Go Home

Chevrolet Volt Review and Test Drive – Milford Proving Grounds

Chevrolet Volt Review and Test Drive (From a Volt Enthusiast)

We arrived at Milford Proving grounds on just after noon on Wednesday July 14th.  The first thing to greet us at the entrance was no less than a pre-production Volt and a transformers yellow Camaro.

  Milford Proving Grounds Volt and Camaro

I thought to myself, if you were going to visit Detroit, Milford is about the coolest place to be.  The weather that day was clear, hot and a little balmy – I would estimate about 92 degrees F at 50-60% humidity.  Despite the heat, I was happy with how the weather broke, considering that the day before there was a driving rainstorm and generally cloudy conditions.  While I would have preferred a San Francisco summer, I couldn’t complain.  It would also be a good excuse to find out how good the air conditioning was in the Volt.

We checked in to security, and unfortunately I found out that we would not be able to take our cameras into Milford Proving Grounds for the Volt test drive. Primarily this was in case we happened to see a 2014 Camaro or Corvette (I did end up seeing some camouflaged cars and some very new looking Corvettes driving around).  Nonetheless, they would be bringing the Volts outside of the secured area so that we can touch it, feel it, and take photos and videos.

It was a short wait before we saw two crystal-red Volts roll into the parking lot at security.  Keep in mind that no photos of the red Volt had yet been released at the time, so seeing the red rendition of the Volt very striking and novel.


Walking up to the Volt, I had noticed some minor changes since I drove the Volt in San Francisco – a testament to the ongoing development of the Volt and how much engineering, testing and refinement still being put into the car.  Notably, the leather seats had changed – instead of being a solid black, they are now two tone beige and black.  Also as others have noted before the shifting lever was changed from the full palm shifter that we’ve seen before to a more conventional one, but sharing the same glossy trim.  I would find out later that the reason for this change was from feedback that people were jamming their fingers between the shifter and the shifter recess when moving the car into “park”.  Check out the video below to get a walk around of the Volt.

There are some interesting details that you can see in the video that I’d like to point out.  First was that the Volt’s faux grill is made of a glossy plastic – probably injection molded.  Next, the wheels are 17 in polished rims, equipped with 205/55 R17 Goodyear Assurance FuelMax Tires.  Although many of us were attached to the 20 in rims on the concept, I found that the 17’s very comfortable looking, and notable.  As you approach the trunk section of the car, you can peer inside to see the rear seats that fold flat with the rear center console, creating a very useful cargo area.

In the Volt’s Trunk

It was at this point where I starting talking to the Volt engineering, Trent and Valerie about what was under the floor mat of the trunk compartment.

Chevy Volt Trunk

In the photo, you’ll notice several interesting things.  From the left, the 120 Volt 20-foot Charging Cord equipped with the Volt (More on this and the plug in process later).  Next, you’ll notice in lieu of a spare tire, there is a 12 volt compressor with a tire repair kit attached to it – an alternative to trying to fit in that spare.  Finally in the center you’ll notice a 12 volt standard automotive battery.  The intention of the battery is to run the car’s computer to do pre-start up diagnostics and also to power the electronics that will switch on the high voltage battery.  You can also still give a jump to anyone who needs it as the terminals are readily accessible through removable plastic tab panel.

Back Seat Comfort

I moved back forward in the car to check out rear seating comfort – as many have asked.

Volt Rear Seat

The photo you see is with the driver’s seat in the full – rear position.  To give you an idea, I am 6’2” tall, and while in the driver’s seat in the full rear position, I could easily reach all the pedals, but my most comfortable position would probably be one notch ahead of that.  The Volt has all manual seat adjustments to reduce on weight and cost.  Given that the front seat was in the full rear position, I had a hard time swinging my legs into position behind the front driver’s seat (it was nearly a contortion act).  So if you had a tall 6’4” person driving in the front with the seat all the way back, you could probably comfortably fit a person who is perhaps 5’6” at the tallest.  A good rule I thumb for that maximum tandem seating height I think would be 12’ total height.  Meaning two people who are 6 foot tall sitting tandem (6+6=12) would be comfortable.  Keep in mind comfortable in a compact car does not mean the back of your BMW 7 series where you can stretch your legs out, but that you can comfortably sit without any appendage being constrained by anything. 

Legroom was the primary factor of comfort concern, the driver’s side headroom is very good and the rear headroom was not of concern to me.  I never bumped my head when we actually drove the car later in the day.

The Charge Port

Moving farther forward, we can now look at the charge port door and the way in which that is actuated. 

Chevy Volt Charge Port

You will notice that the charge port door has a shroud that interfaces with the plug to protect it even when the door panel is closed.  The door itself is actuated by a button located on the driver’s side door, ahead of where the window rocker switches are.  The door is spring loaded, so a pressing the charge door button releases a latch, and the door springs to the full opened position.  The door swings out quickly, but towards the end of its travel, its motion in dampened so that the door does not slam into stop on the other end. 

Chevy Volt Charge Door Button Close Up img_1030

Now that the door is opened, I asked to be able to “plug” in the Volt in.  The SAE J1772 plug was light in the hand, as the entire housing was plastic.  Sliding the plug in was quick and easy, in the plug the tolerances were a little looser so you didn’t need to line everything up perfectly, but pushing the plug down resulting in a confident snap into place.  Releasing the plug was as simple as pulling a trigger release on the bottom of the plug and pulling it out.

Inside – The Center Console

After viewing the charge door, I sat down in the Driver’s seat to get a feeling of ergonomics and placement.  It was simple to get in, and the leather seat was firm and supportive.  Looking across the dash and center console, there are some interesting things to note.

Volt Center Console

On the center console, this version was the black version (white is the other option).  You’ll note that while the main aesthetics of the car have not changed materially over time – there are same refinements and variations to what the specific buttons do.  The buttons on the center console are capacitive touch, which means it detects the presence of your finger when you touch it instead of being triggered when you depress it.  There are small finger indentations for you to help find the location of each button.  Of course, the beauty of having a capacitive touch panel like this is that you can easily reconfigure the actions of each button, and simple re-etch its icon onto the center console.

Most of the functions are self-explanatory, like a normal car.  What’s different of course starts with the Power button.  No longer an ignition, the car powers on if when press the power button while depressing the brake pedal.  Power up consists of a short audio cue followed by both lcd screens showing a Volt logo animation. 

Moving up from the power button you’ll see the Drive Move and Leaf Symbol.  The Leaf Symbol Controls what climate mode the car is in (Comfort or Economy) while the Drive mode button toggles between the different driving modes (Normal, Sport and Mountain).  Moving to the right, you’ll notice also the lock/unlock buttons on the center console, and tune / volume controls, which are rotary switches with rubber finger grips.  I don’t remember clearly but I believe the “tune” rotary switch had detents while the volume switch had no detents in the rotation.

Lastly you’ll notice the said shifter that is now much more traditional.  This is a case where ergonomics and user experience trumps aesthetics.  While it’s no longer a full palm shifter, I’d have to say the shifting experience was much more familiar and comfortable as you can now easily grip the shifter with your palm and several fingers.  The shifting detents and tactile feedback was tight and pretty much like a conventional car with the stops and detents where you expect them.

Inside – The Instrument Panel

Moving onto the main instrument panel, you’ll see the LCD Instrument Panel in the “Off” Position.

Volt Instrument Panel

The Panel itself is very bright, and easy to see even on the bright summer day it was.  The resolution on screen was good.  My estimation was that for the 7 inch screen it probably had 800×600 pixels – about the resolution of a good laptop screen, but not for watching HD movies on.  Both screens were of similar resolution, and the animations that played were at good frame rates.  Much better than the Gen 2 Prius screen, but not quite to the level of a 120hz HD Screen.  Think traditional movie of 24 frames / second.  It was smooth but not silk.

Under the Hood

Stepping out of the car, I stepped forward to finally see what was under the hood of the Volt.  You can see a good view of this in the video below, as well as a higher res photo.

Under the Hood of the Volt 2

The first thing to notice is the presence of three separate tanks for coolant.  One on the far left for the internal combustion engine, and two in the front near the grille for the Power Electronics and the battery.  Each component, engine, battery, and power electronics has its own separate cooling loop.  (You’ll notice that the tubing to the engine coolant is much heavier duty than the electronics coolant).  The engine air filter sits on the left between the coolant tank and the engine block.  The engine block itself without surprise sits right in the middle.  That assembly looks conventional, with easy access dipstick and oil fill cap.  You will note that the cap says 5W-30 Oil, which is very typical for smaller engines.

While I did not get a very clear view in this very tightly packaged engine compartment, I did not notice any separate belts for the engine.  No surprise as the whole car needs to operate without the engine being on.  Trent also mentioned that the Gasoline Engine and Generator were part of the same assembly.

Moving right you’ll notice the DOT3 brake fluid reservoir and in front of it, the power electronics / traction motor unit.  You can’t see too much from here other than the many orange power cables going to the power electronics assembly.

I managed to get a couple videos where Trent was describing some of the features under the hood.  You can view those below.

After this we paused for a quick photo op, with Elena and I, and then we packed up, ready to drive out to the secured part of Milford proving grounds.


At this point, we had to stow our camera equipment, so you’ll have to imagine without visual aids the rest of the driving experience.

I jumped into the shotgun seat of one of the two Volts, and Valerie proceeded to drive us inside Milford proving grounds to the Ride and Handling Loop where we would be driving the Volt.  Remember the “Hot” Day that I mentioned?  Well this quickly became evident as we pulled away as the Volt had 30 minutes or so to bake the Michigan heat.  Sitting in the front, I was able to play with all of the center console controls.

Cabin Air Conditioning

First, the air conditioning – there are two capacitive touch buttons under the actually display to control fan speed and temperature.  I toggled it down to 68 degrees and maxed out the fan speed.  Cool air came pouring into the cabin, but something seemed wrong, it wasn’t really enough volume of cold air to cool the cabin.  It helped, but wasn’t adequate for the Michigan summer.  Valerie then pointed out and corrected this – as I noticed that we were in “Economy” Mode, which basically limited the power available to the cabin cooling system by capping out the blower speed and consequently the cooling power available to the cabin.  With one press of the “Leaf” Button, we were into Comfort Mode, and instantly the blower fans went up to full power – blasting me with a torrent of chilled air – Much Better!  Quickly the cabin became comfortable despite the 92 degree summer day, and I eventually turned down the fan speed as it was no longer needed.

Comfort taken care of, I proceeded to play with the on board sound system and radio.  The radio interface was simple and straightforward, clean but not pretentious.  I found the “90’s Channel” On XM radio and turned out the volume.  I believe, but didn’t confirm whether the speaker system in the car was Bose.  The sound that came out of the speakers was clean and generally decently equalized.  To give you some perspective, think Bose “Wave Radio”.   It was better than average, but not audiophile or Bass Thumping quality – above par for factory equipment.

Infotainment and Energy Usage

Next, I experimented with the center console “infotainment” display.  I was able to bring up the “Power usage monitoring and watched it as we drove around”  The home screen for power usage showed a diagram of the Voltec Drive train, and where power was flowing, much like the Prius screen does.  Notably, the animation quality was much better, and the screens were crisp.  The buttons on the screen were comfortably sized, though very simple in its implementation.  Most on screen buttons were a rounded outline on high contract black with text in it.  Not like the mobile phone icons you might be familiar with, but I suspect this has to do with a tradeoff between easy readability and aesthetics.  Likewise, when you pressed the button, there was a slight noticeable delay before the button would highlight and actually trigger the action with an audio cue for response.  That delay was probably about a quarter to half second.  I later found that the reason for this was not a technology constraint, but rather adding in that latency helps prevent inadvertent presses and that was a usability decision.  Personally, I prefer crisper button actions, but I’m sure the guy wearing his glove in an area where winter actually gets cold would appreciate this.

One thing I noticed right away on the energy usage screen was that when we had placed the car into “comfort” mod with air conditioning at full blast, the estimated electrical range dropped from 40 miles to 32 miles.  This may give you an idea of what to expect depending on your accessory load.  After watching the true mileage for a while, the estimator tool seemed to be fairly accurate.

I paused quickly to look up as we drove past the Hybrid Vehicle lab, where about 20-30 Volts in varying states of build (from the Cruze-Volts to the Early Iv’ers) were parked under an awning receiving electrical charge.  Very cool and interesting to see the work GM is still doing using the engineering builds.

The Test Drive

After 10 or so minutes, we arrived at the start of the Ride and Handling Track at Milford Proving Grounds, which is a 4 mile loop with all sorts of road conditions built into it, from chatterboxes, permanently slick roads, simulated railroad tracks, very deep bumps and potholes etc.  Knowing that the Volt still had substantial electrical charge, I opted to drive last, so as to get a chance to drive with the charge depleted.  (Fortunately for me the hot day and the air conditioning on full blast helped eat up that charge faster)

For the first several laps, I sat in the backseat of the Volt, behind the driver.  As I mentioned before, rear seat comfort is primarily a function of the combined height of driver and passenger riding behind.  As the drivers sitting in front of me were generally under 5 ‘9” I did fine in the back.  Headroom was fine and I had a place for my legs that was not in the back of the driver’s seat.  As the other drivers took their first laps around I made note of the things I would do when I got behind the wheel.  About 40 minutes later, we switched and I got behind the driver’s seat of the Volt.

Stepping in was a more familiar feeling this time – as you might already know, I got a chance to drive it in San Francisco, so this time it was not altogether new.  First I adjusted the seat to my comfort position, one notch from the farthest travel back.  Next, I adjusted the review view center mirror, and found to my pleasant surprise that rear visibility was very good because of the extra glass in the hatchback assembly.  Side window visibility was also good and front visibility unimpeded.

I set the car into reverse and saw the backup camera view appear on the center console display.  The implementation was very backup camera standard, with a decent view and colored distance hash marks showing how close you were to anything behind you.  Additionally if you got close to anything, a warning icon would appear on the screen and an audible beep would alert you to your proximity to another object.  The beep become faster as you approached something – in this case another car parked at the start of the handling track.

Shifting it into drive, I pulled away from the lot, stopped the stop sign right before the entry to the ride and handling loop.  I swung the Volt slowly around the corner, gingerly pressed on the brake to bring it to a near stop, and then pushed the pedal to the floor.  Without hesitation, the Volt pushed us into the back of our seats with a constant G Force.  10, 20, 30, 40, 50, 56, 60, 65, 70 – During the middle of the acceleration Valerie help me toggle the Volt into Sport mode, and sure enough about another 20% power was unlocked, giving you a little extra spirit all the way along.  I didn’t time it, but compared to other cars I’ve driven, the 0-60 felt like it was around 8-9 seconds as advertised.  It was quicker than a 4 cylinder compact car (Unless you have a turbo), and probably just a hair less than a new model V-6 sedan that makes over 220 Hp.  This was with a 3800 lb car + a full passenger load of 4 normal sized adults. 


The acceleration profile of the Volt of course was very different than a typical gas powered car.  With all the torque at the beginning and no gear shifts, you were basically pushed into your seat for the first 3-5 seconds of the acceleration without relent -unlike a traditional gas car that gets more torque at high rpms.  There was a noticeable power fade around 45-50 MPH even with your foot all the way down, where the feeling that you were getting pushed into the back of your seat eased.  (This corroborates with the information that the peak power was engineered to be around 48 mph).  The acceleration loss was noticeable, but not huge.  It seemed like perhaps 20-25% less than in the 0-40 mph range. 


Once up to full speed, I did some “passing speed” behavior to the extent that the course and the test engineer would let me. When I  accelerating from 50 to 65 mph and 55 to 70 mph, the passing acceleration performance overall now felt more like a normal car, but without the downshift and sudden speed boost.  Definitely adequate for highway driving and you’d be able to overtake a slower driving car with ease, but in this regard, not as exciting as to 0-45 where you were actually pushed into your seat.  Short summary on acceleration, fantastic for freeway onramps, adequate for passing speeds, where adequate is performance similar to a typical 4 cylinder compact car at highway speeds.

Ride Quality

Coming out of the first stretch, we now entered the stretch of road meant to simulate different road conditions, like sudden bumps, big dips in the road etc.  Here is where I could get the best evaluation of the ride of the car. Having driven many different compact and mid-size sedans of varying brands, the closest I would pin the overall ride quality of the Volt would be a shorter wheel-based Ford Fusion.  It definitely rode more like a mid-sized car than a compact car, undoubtedly due to the increased weight of the vehicle.  It did not really seem to “bounce” over the bumps and dips and compact Corolla and Civics often feel like, but rather rode through them with the suspension taking the brunt of the hit.  Compared to other midsized cars, like the Hyundai Sonata, Toyota Camry, Chevy Malibu and Ford Fusion, it was closest to a new Fusion.  Whereas the ride on the Camry and Malibu was a little softer and the Sonata just a little less refined, the Fusion has a firmer ride to it, but overall is still tuned for comfort.  It absorbed small bumps very well, but the larger bumps you would feel a little bit more of it.  Never did I really feel in the handling loop that I would bottom out the suspension though.  Because of the shorter wheelbase, the pitching of the car felt more compact than mid-sized, as you’d notice pitching a little bit more going over, and recovering from a bump more so than a mid-size vehicle.


I now entered into the handling portion of the loop, where curves of varying radiuses appeared before me.  You might have noted in my previous review how the steering feel was, but as a reminder, the steering was power assisted to a level typical for most cars.  Not loose feeling, but not race car like either where you can really feel the road.  This element as well seemed primarily designed for comfort over performance.

Turning into the corners, you felt very little initial body lean – but as I took progressively aggressive corners at 50 mph, you eventually fell the suspension give way to some body lean.  To get this feeling, I was taking corners at above normal driving speeds, but not racing fast.  (I was doing 50 mph in a 40 mph suggested corner).  This gave me much better perspective than the parking lot ride I did since I could not feel the car handle at highway speeds.  The body lean at higher speed and tighter corners was a little dose of reality.  I guess there isn’t much you can do you compensate for the loads you are putting into the suspension of an already fairly heavy, and loaded down Volt.  Compared to other cars in the category I thought that this part – again was average.  A well tuned mid size like the fusion felt a little better (lighter) in the corners.  It’s the price you pay for the weight of all the electronics/battery on board.

I’ll echo from the previous review that one positive aspect of the low CG of the Volt was that the body lean never went so far as to feel like you were going to lose traction.  So the Volt stayed confidently planted on the ground, even while you did notice that bit of body lean.  So this aspect of the car helped compensate a good deal for the increased weight.

Braking Performance

Braking performance on the Volt was excellent.  Not only could you not tell whether the car was regenerative braking or disc braking (except for the feedback on the instrument panel telling you that you are braking inefficiently) but the stopping performance was great.  If you slammed on the brakes, it was responsive and fast, especially given the weight of the car.  4 wheel disc brakes no doubt help out here, along with very careful calibration and performance merging between regenerative and friction braking.

In the last segment of the ride and handling loop we drove across a chatterbox / permanently slick surface as well as some simulated railroad tracks.  This is where the weight of the vehicle actually helped pick up the terrain of the road.  For small road disturbances like small bumps and railroad tracks, the suspension absorbed the road very well, and you didn’t get the feeling of getting bounced around.  At higher speeds you can feel the car fishtailing a little on the super slick chatterbox surface, but nothing alarming.

Mountain Mode and Charge Sustaining Mode

I came around for my second lap, with the intention of seeing how the Volt drove in charge sustaining and mountain mode.  Starting the lap, I noticed that there was about 6 miles left of electric range, so I figured this would be in the territory where mountain mode would force the generator on.  With three presses of the “Drive Mode” button, I was into mountain mode.  The first press always sets the default to normal mode, the second to sport, and the third sequential puts it in mountain mode.  With the mode change the engine roared to life, the range indicator switched to gas, and I was driving in Mountain Mode.   This transition was more aggressive than others have described in normal mode as the engine is quickly spooling up to start recovering charge, instead of transitioning over very gently to an idle 800-1000 rpm.

I estimated that while cruising, the engine ran at about 3000 rpm as it was trying to recover to the higher charge point during normal driving.  If you pressed hard on the accelerator, the engine would increase its speed up to 4000 or so rpm, giving you some familiarity with the fact that you’ve mashed the pedal.  In that sense the engine reacted very much like a typical car would.  It was clear that the engineers were trying to do some simulation between pedal input and engine rpm, as well as the fact of course that you are demanding more power.

As soon as you eased off the pedal, the engine would gradually spool back down to 3000 rpm, giving you some feedback that yes, indeed you’ve pulled off the gas pedal.  This affirmation in my mind was quite useful as it gave you some feedback that your car wasn’t about to “run away”.  Imagine if you removed your foot from the pedal and the engine did not give some feedback.  That would likely be a jarring and confusing situation.  Though the engine of course didn’t spool back to lower rpm, the fact that it reduced rpms and noise gave you some confidence that your input was being acknowledged.

All the time, there was no difference at all in driving performance.  I found out earlier that day why that was the case from Andrew Farah, who described the control logic loop.  Basically what happens is that the computer detects your pedal position, that logic loop then send a signal to the power electronics on controlling the traction motor, the power electronics on the traction motor then sends a signal to the engine controller, which determines based on the current draw and current drive mode what engine rpm to put out.  The engine and battery are on a common DC bus.  So basically your foot controls what the traction motors demands, and it doesn’t care whether it’s getting juice from the battery or the gas engine directly.  It’s then up to the gas engine to best estimate how much power to put out to either deliver the needed power to the drive motor or to charge the battery.

Satisfied with the mountain mode experience, I toggled modes back to normal, and the engine spooled down eventually shutting off, leaving me back in normal drive mode with 6 miles of charge still remaining.  Eventually I got to experience the normal transition from electric to gas, which as people have described before was totally seamless.  You could not sense any vibration as the gas engine game online and with the tire noise at 30-40 mph, you can hardly hear the gas engine if you are just cruising around.  I noticed that the gas engine typically stayed around 1200-1600 rpm if you were just cruising around at 40-60 mph on flat terrain, with the AC on pretty hard.  For normal, non aggressive, non hill climbing driving, the gas engine for the most part was out of the way.  You could hear it, but it was a dull drone with no perceptible vibration in the cabin.  Once again, there was no difference at all in driving under those conditions.

As I finished the last lap and pulled into the parking lot, I had to do my favorite thing, pull the pedestrian alert lever.  (I think I’ll be doing that a lot when I buy a Volt)

MPGs in Charge Sustaining Mode

Since you’ve read this far, I’ll give you what I saw as the MPGs in charge sustaining mode.  Basically, I watched the energy display over a period of time.  In total, during our drive we used 0.40 gallons of gasoline.  In that period of time, the estimated miles on gas resulted in an MPG measure varying between 30 and 40 mpg.  Keep in mind; this is with the AC on full blast, us driving inefficiently and also an unknown amount of extra charge that was put into the battery from using mountain mode for part of the drive.  Of course, given the sample size of actual gasoline used – you’ll have to take this with a grain of salt.  However, I suspect that you can get 50 mpg if you are not using air conditioning, and driving conservatively.

To Close

I hope you’ve enjoyed reading the full review of a Chevrolet Volt from a Chevy Volt Enthusiast!  Please let me know if you liked it by leaving a comment – or if there is a specific topic I missed also leave a note and I’ll answer to the best of my ability. Also if you’re ever in Detroit, make sure to stop by the Volt Bar :)

Chevy Volt Bar

31 Responses to “Chevrolet Volt Review and Test Drive – Milford Proving Grounds”

  1. Fred says:

    Very nice review, I appreciated all of the detail. I’m enjoying the blog, keep up the good work and hopefully I’ll see you on the road in December when we’re both driving our Volts. :)

  2. PatrickZWang says:

    Thanks Fred! Whereabouts are you – I’ve already got in mind that every time you see another Volt you should hit you pedestrian alert as a way of saying hi :)

    Good luck!


  3. Austin says:

    Hey Patrick-

    Great writeup & pics, thanks! One thing I’m unclear on is the roof… it looks like glass, but can you see through it? What’s it look like from the inside? Is it sunroof-esq or totally opaque?

    • PatrickZWang says:

      Hey Austin,

      The roof is painted black. It looks cool – but it’s a standard steel top with black paint.

      The concept had a opaque polycarbonate top, but that didn’t make it into production. (I bet for safety reasons)


  4. Kevin says:

    Nice review. I’m already enthusiastic. I just wish the Volt had come out last year when I was car shopping.

  5. Shaft says:

    Terrific, especially your Mountain Mode experiment.

    Did you ask the engineers how the “transmission” works? (How is the engine connected to the generator? Is the generator ever connected to the drive train to regenerate? Are there any gears between the traction motor and the wheels? What clutches exist and why? etc.)

  6. Shaft says:

    Also, the video got cut off at a crucial moment. Did the engineer actually verify that there are only 2 motors, one for generation and one for traction? There has been some discussion in other forums about the possibility that there are 2 traction motors built somehow into the same housing.

    • PatrickZWang says:

      Hey There,

      I haven’t figured out the specifics of how this would work, but from what understand the transmission itself involves an E-CVT (electronics CVT) One of the engineers mentioned that is has a E-CVT implementation. The basic concept of an E-CVT allows for gearing (usually combined through a planetary gearset of some sort) that creates mechanical advantage through the relative motion of the gearing components.

      Some variations of the Sun Gear and Ring gear powered, or Sun + Planet Gears.

      I haven’t gotten a clear explanation of how this might work exactly – or how the gas generator becomes involved. But I think it’s safe to say that the transmission is more advanced than just gas engine+generator piping electricity to a single traction motor, with a direct gear down.

      Hope that helps!

      • Shaft says:

        Well, it’s interesting that the engineer said there is an E-CVT. But that only makes me more confused since I cannot imagine how that would work if the ICE-GEN unit is completely disconnected from the traction motor. The Prius relies on that connection to make the E-CVT work.

        In your accelerations up to 70 MPH, did you ever feel any kind of shifting? Or are you convinced from your test drive and/or converstaions with GM engineers that there is only one gear between the traction motor and the wheels?

        • PatrickZWang says:

          Yeah I don’t understand the implementation, but that could be a new secret sauce. Given that the Toyota PSD Drive if definately patented (though I guess Toyota recently had to settle that)

          I imagine the implementation of this E-CVT is something different.

          There was definately no perceptible “shift point” in the acceleration at any point. Though that does not mean it was a fixed gear ratio. As mentioned it could be a CVT which would make effective gear ratio changes inperceivable.

          I have the pedal to the floor from 0-70 and aside from a little power fade after 50 mph, it was pretty much linear acceleration.

  7. RB says:

    Great review! Very thorough. You mentioned “you’ll notice in lieu of a spare tire, there is a 12 volt compressor with a tire repair kit”. Is this compressor meant to be used only for fixing flats or is it a convenient way to put add’l air in the tires when they are running low?

    • PatrickZWang says:

      Hey Robert,

      I don’t see any reason why you can’t use the12 volt compressor to pump up your tires periodically. It’s there for fixing flats, but it’s probably just like any other 12 volt compressor you can buy just about anywhere else.

      I didn’t think about that utilization! But useful in any case! (I have a pancake style compressor at home)

      As long as you don’t have a blowout or a large puncture I suspect you should be ok.


  8. Shaft says:

    Hi Patrick,

    Another question.

    You can see 6 wires in the front for AC to/from the generator and traction motor. But you can also make out 4 wires in the back close to the firewall. No doubt these are to/from the battery. But I would have expected 2 wires for DC. Any idea why there are 4?

    • PatrickZWang says:

      I am not certain exactly what those are for – I can only conjecture based on what I’ve seen at the battery lab. Presumabally they could any of the following.

      1.) Signal / data cable bundles (though that would not explain why there would be an additional two of them) We definately know that the battery hookup has many failsafes built into it and as the battery lab mentioned they sample over 500 inputs / second.

      2.) A pair of cables running to the rear 12v APU/battery. Both the battery and the dc/dc converter that takes high voltage down to 12v for accessories and computer are in the rear of the car behind the passenger seats.

      3.) HVAC power. (less likely, but we know that the compressor runs at high voltage for efficiency reasons, perhaps stands to reason that the heating elements would as well.

      Those are my guesses anyways!

  9. DEREK says:

    you did a great job.considering buying a volt

  10. no comment says:

    could you describe the red color? it is very difficult to perceive color characteristics from photos and videos because the lens exposure can throw it off from what it would actually look like to a viewer who was actually present. for example, did it seem like a bright/loud red or darker shade of red? the brightness of the color seemed to vary widely so i would be interested in your perceptions as having actually seen it. i’m just looking for general impressions of what your visceral reaction to the color was. thanks.

    • PatrickZWang says:

      Hey There,

      Thanks for your note! The Red is available on other GM Models, so if you want to get a firsthand look you might goto your local Chevy dealer and see if they have the Crystal Red Tintcoat.

      As far as my impressions – you are right the photos show up brighter than it actually is. The closest to what it actually it is is the Volt Rolls in Video. It’s a deep red with a shiny depth to it. It looks like it has two layers, the deeper red base and a glossy overtone.

      It actually looks really good in person on the Volt – Much better than a flat candy apple red, it looks like there is depth to the paint like a really freshly waxed car. (Though it may have been freshly waxed as well)

      The only reason I did not order was because I could not be caught dead in a red car being a Cal Graduate (We are Blue) – But in another life red would have been a great pick.

      • PatrickZWang says:

        I noticed you mentioned Visceral Reaction – I thought of “Royal Crimson” as being the closest thing. Something a little regal. Not sports car FAST red, but a stately, regal and composed red.

        Hope that helps!

      • no comment says:

        you got something against stanford? hey, take the red one and then take comfort in driving around in your volt while playing dvd’s of “the play”. :-)

        on the other hand, you could order the red but demand that the dealer call it “crimson” and not “red”. then you should be ok – unless you’ve got bicoastal animosities and have also got something against harvard (hahvahd) as well.

        thank you for your comments, i’ve been taking note of a cadillac cts in red that i regularly see. it’s a nice looking red, and i think that the red/black contrast in the volt looks good.

        • PatrickZWang says:

          Yeah – Too Bad they didn’t do the transformers blue – I would have jumped on that one. Went with the Viridian Joule in the end – its a nice unique color. (Black & White & Silver are a little sedate for me – I like bold colors)

  11. Ken says:

    Patrick–I really enjoyed your very thorough review of the Volt. I’m a Bay Area aerospace engineer and a Kar Krazy, and I’ve been fascinated by the Volt since it was first announced. Although the Prius is (in my mind) a really outstanding piece of engineering and Toyota gets an A+ for sticking with the car and developing it into a great product, I think the basic concept is flawed. The Volt, on the other hand, (again in my opinion) is exactly the way the hybrid architecture should be implemented—decent range on batteries plus extended range on the ICE for longer trips and no worries about running out of charge, plus plug-in recharge capability with reasonable recharge times on 120VAC. The Nissan LEAF, for example, can’t compete on either of these parameters—range worries and reasonable recharge time.

    I had a couple of questions that you didn’t address in this writeup that perhaps you know the answer to.
    1) What’s the estimated (or guaranteed) life of the LiPo battery and what is the replacement cost?
    2) The Volt actually connects the ICE to the wheels directly under either a) heavy load conditions or b) at higher highway speeds in order to increase overall efficiency. Did the GM engineering team go into any details of how the E-CVT accomplishes this? The ability to have the ICE drive either the generator and/or the car’s wheels is very interesting.

    Lastly Patrick—are you a Cal guy? After this year’s Big Game I can’t believe you’d admit to it.


    • PatrickZWang says:

      Hey Ken,

      Thank god the football season is over – hopefully next year will be better. Yes I am a Cal Guy – and it was painful to watch the Defense hold 3 teams to 1 offensive touchdown each and we still can’t win.

      To answer your questions.

      1.) GM Warranty’s the pack for 8 years / 100,000 miles. GM has overprovisioned the pack, so basically at the start of life you won’t have access to all the pack energy, and as the pack degrades, the software opens up the pack usage to keep your electric driving distance consistent over the 8yrs/100k miles. No word on replacement cost – I suspect the idea is in 8 years, who knows how much a pack will cost?

      2.) Yes the Volt eCVT is very interesting, with 6 distinct operating states and a pretty sophisticated software algorithm. I would write a review, but MotorTrend does it much better.


      Would you happen to be from Stanford Aerospace? Know a guy by the name of Steve Rock?

      Enjoy :)


      • Ken says:

        Patrick—First, thank you again for the excellent review and getting back to me on my questions. Second, the vaunted Cal defense didn’t look all that good against the Cardinal. However, the loss to Washington in my opinion was on Tedford’s shoulders. I think he failed to motivate the team and they were flat—they should have waxed the Huskies.

        Lastly, you’re right on the money regarding Stanford Aero and Astro. I have a couple of graduate degrees from Stanford Aero and Steve Rock is a long time old friend of mine. You may also know Dave Powell—Steve and Dave were professors together in the Aero Dept for many years and Dave is quite an expert on automotive technology. He and I discuss hybrid vehicles (Prius and Volt) quite frequently.

        One last question: what’s your strategy and/or opinion about buying or leasing a Volt in the Bay Area? It seems that the Volt will be in really short supply for at least 6 months to a year. Do you have any qualms about buying a brand new extremely complex product first time out of the box? Remember the horror of the then-new BMW 7-Series a few years ago where BMW actually had to buy back a number of cars they were so bad.

        Any thoughts>

        Best regards, Ken

  12. PatrickZWang says:

    Hey Ken,

    Much as I would not like to admit it the Cardinal has a strong team this year to be respected in many regards. Nothing flashy like the Ducks, but well composed and balanced. Its a shame that they probably won’t goto the Rose Bowl because of TCU though.

    As far as Buying a Volt in the Bay Area, unfortunately AFAIK, they are sold out well into 2012 (unless you find someone willing to sell you their position) So in that sense, buying early won’t be a problem anymore.

    For me, I signed up to buy basically as soon as they had a price and could take ordered, consequently I ended up with VIN #10. Fortunately I’m not really buying the Volt sight unseen as I’ve had a chance to drive two pre-production models and ride in a basically completed build. While there are risks with new technology, the feeling I am getting in experience the completeness of the car and the attention to details when I spoke to their engineers inspires enough confidence to me that there won’t be a material show-stopping design flaw that will emerge in production. That combined with the fact that the most expensive (and relatively new components in the car) the battery and electric drivetrain are warrantied for 8 years 100k miles makes me willing to take the first adopter risk.

    You don’t happen to work with any FIRST teams in the Bay Area do you? I know that some LM employees are getting around with that. I still coach a team down in Cupertino and maybe we’ve just missed each other in plain sight. If you and Dave are interested I’ll let you know when I get my car and we can have a little technology geek session.



  13. Ken says:

    Patrick—-really disappointed to hear that the Volt is completely sold out for 2011 and into 2012. I had thought once the car was in dealer showrooms and that if I really liked the car in person, I might put one on order—I guess that’s not going to happen. On the other hand, it’s really great news for GM and the whole concept of alternative types of automotive propulsion—plus, the Prius needs some viable competition.

    I would absolutely love to have a “geek session” with you when your car arrives. I’m sure you’ll be looking for excuses to drive it, so heading on down the Peninsula where I live should be a nice gas-saving outing. Please do let me know—if you contact me at my work e-mail I’ll be happy to give you the rest of my contact information.

    I’ve heard and seen the acronym FIRST before and I actually think some of my colleagues participate in it, but I’m not familiar with exactly what the program is.

    Best regards


  14. Fletcher says:

    Considering a Volt for the desert area of southern Utah. Wondering your thoughts of the black roof on all Volts coupled with the substantial glass at the front and rear and how the AC might deal with the heat load from high sun angle and very high (above 105 degrees F) temperature. Not too worried about the electrical draw and cost of charging as I will have 3kW of photo voltaic panels on our home. Just wondering if the cars AC can actually keep up under the climatic conditions in St. George, UT summer. Seems like GM would make a roof that at least matches the car body color rather than black.

    • PatrickZWang says:

      The AC on the Volt is very good as long as you let it draw the electrical load – the compressor runs at 320 volts off the high voltage battery (it will reduce your all electric range of course, under full load I’ve noticed it will take your AER from 38-40 miles down to about 32 miles)

      Recently I drove the Volt through Reno, in direct 95-100 degree days with sunlight – on full blast AC it was very comfortable. you will notice that with all the glass the car does heat up quite a bit after you park in the sun though and with black seats you get your normal “leather roasted bum”, but the AC can keep up well once you get going.

      Your back might get a little sweaty (especially with leather seats) but I don’t know any other way around that even with other cars unless you have cooled seats :)

      I have heard rumors that future versions (maybes 2013?) would have a matching body color roof.

      Thanks for visiting!


Leave a Reply to Austin