General Motors confirmed it will no longer manufacture any more Chevrolet Spark EVs, and that production stopped in the summer of 2016.
The automaker valued lessons learned from the Spark EV as it prepared to launch the Chevy Bolt in December.
“We’re excited to build on the great experience of our electrification program, including Spark EV, to introduce the first affordable, long range electric vehicle, the Bolt EV,” Chevrolet spokesman Fred Ligouri said.
Revealed in June 2013, the 2014 Spark EV was GM’s first mass production all-electric vehicle, though the company confirmed that only about 7,400 units were sold. The electric car with 82 miles of range was first sold only in California and Oregon, with Maryland added in spring 2015.
When GM unveiled the Bolt concept at the 2015 Detroit auto show, the company said it wouldn’t replace the Spark EV. That appears to have changed, though GM could stick to the claim with the Bolt offering nearly three times the range at 238 miles and more size and interior space.
In April of that year, GM cut the Spark EV price by $1,650 at just under $26,000 to spur sales. Built at a South Korea plant, the Spark EV is no longer listed as an available electric vehicle; and it wasn’t refreshed to match the front exterior of the 2017 Spark.
HybridCar’s Dashboard reported that the Spark EV had 3,035 vehicles sold in the U.S. during the 2016 calendar year, up 15.4 percent over 2015 sales.
Ending Spark EV production brings GM’s current electrified vehicle offerings down to the Bolt all-electric, Volt plug-in hybrid, and Malibu Hybrid, Ligouri said.
GM has high hopes for the Bolt, which should surpass the Spark EV’s 7,400 units sold mark in the first half of this year. It sold less than 600 units in December with the launch. Chevrolet officials said last week that U.S. sales should reach 1,200 vehicles in January, and they came close at 1,162.
As tradition would have it, January plug-in electrified vehicle sales were down compared to December, but of all cars for sale in the U.S., the Chevrolet Volt’s 1,611 units were enough to place it first.
The Volt’s sales were up 62-percent over January 2016’s sales when the second-generation extended-range EV was still rolling out following first deliveries that had begun in October 2015.
January 2017’s Volt sales were however well down from December’s all-time record 3,681 sales, but then others, such as those of the Tesla Model S and X, Nissan Leaf, and more usual sales chart leaders were also down.
December, being the month before the end of the year, received a double boost from both consumers and automakers explaining why it saw an estimated 5,300 Model S sales, while January saw less than one-quarter that many, or an estimated 1,200.
For car buyers, December is the end of the tax year and positions them for the shortest wait until they can recoup a federal tax credit. January, on the other hand, is the beginning, so the wait is now longest.
For automakers like GM and Tesla, they each had something to achieve. For GM, a push was made so the Volt’s 24,739 sales in 2016 exceeded previous highs in 2012 and 2013 in the 23,000 range. For Tesla, it was hustling to make its year-end guidance, and indeed it did set a record 29,156 Model S sales, and 18,023 Model X sales. Otherwise, the California automaker traditionally bears down hard at the end of fiscal quarters like a school kid cramming late for an exam, and it especially pushed units out the door in December.
Thus the Model X was in a similar situation to the S. In December, an estimated 3,300 were sold. In January, but 1,000 are estimated as having been delivered.
As for the Nissan Leaf, it too was down from 1,899 sales in December to 772 in January. The Leaf’s sales may also be explained by the fact it is on its way out, as a revised 2018 model due for reveal is expected. So it goes – out with the old, in with the new.
And on that note, the Volt’s sibling, the Bolt EV, trailed the down estimated month of the Model S by a mere 38 units, as its 1,162 January sales made it the fourth best seller. That’s OK, as it is still being delivered in only a few markets in its second month for sale, including California which usually speaks for half the U.S. volume.
Bolt EV at media drive in Portola Valley, Calif.
Which plug-in sold better? The Prius Prime plug-in hybrid. After three months on the market, its sales were up to 1,366 units, placing it second to the Volt.
Toyota has priced the Prime within the range of the Liftback hybrid, and incentives can make it net cheaper than the non-plug-in – a decent value proposition compared to gen one which was clearly priced above. Contrary to a speculative report that Toyota does not really want to sell these in volume to all 50 states, media rep Sam Butto said the opposite is true. It is still ramping up volume, but the company’s planners are estimating about 25,000 units in 2017, about the same as the Volt last year.
Prius Prime. Analyst Alan Baum concurs with Toyota that the car is still ramping up, so availability, though reportedly sparse in the first couple months, is due to increase.
So, despite initial reports that the car was not widely available, its marketers answered our question: If Toyota got 50,000 orders for the Prime in the U.S. this year (including many from non-ZEV states), could it fill them?
In a recent crash test by the Insurance Institute of Highway Safety (IIHS), two plug-in hybrids – Toyota Prius Prime and Chevy Volt – earned the highest Top Safety Pick Plus designation, while Tesla’s Model S and the BMW i3 fell short.
To qualify for the IIHS’ Top Safety Pick, a car has to earn a rating of good in five tests – small overlap front, moderate overlap front, side, roof strength, and head restrains. The vehicle must also have an available front crash prevention system that earns a rating of advanced or superior. If a car meets the requirements and passes the assessments, it can earn the “Plus” moniker if its headlights are found to be good or acceptable, as explained in a video below.
With those criteria in mind, the IIHS reports that the Model S earned a rating of good in all of its evaluations, except for the small overlap front crash test, which simulates running into a narrow object. In that specific area, the sedan earned a rating of acceptable.
Other areas where Tesla’s sedan fell short include its headlights, which the IIHS rated as poor, having safety belts that didn’t prevent the crash dummy’s torso from moving forward, and not having hardware that allows the vehicles to make an emergency stop. As USA Today points out, not all Model S sedans built since last October have a front crash prevention system.
The i3 also failed to obtain the institute’s highest ratings, as the electric car earned a rating of acceptable in the seat and head restraint evaluation.
Meanwhile, the two plug-in hybrid electric vehicles, the Chevrolet Volt and Toyota Prius Prime managed to impress the IIHS, with both being named as Top Safety Pick Plus cars.
According to USA Today, Tesla came out with a statement in regard to the Model S’ crash tests saying, “we are committed to making the world’s safest cars, and Model S has previously received a 5-star safety rating from the National Highway Traffic Safety Administration and a 5-star rating from Euro NCAP. Model S has the lowest every probability of injury of any car ever tested by NHTSA.”
Tesla also told the outlet that it is continually working on updates for its vehicles, which will include new software that will allow its vehicles to brake automatically in an emergency situation in the near future.
The 2017 Chevrolet Bolt is an entertaining yet practical car that happens to be all electric.
That’s at least one overarching impression following a 100-mile drive around San Francisco last week in the 238-mile range compact crossover that nets for under $30,000 after a federal tax credit.
While inevitable critics will poke at things they find objectionable, this article’s opening line echoes what’s been said of Tesla’s cars – i.e., they’re great cars that happen to be electric – and earning such praise was an official General Motors goal.
Indeed, chief battery engineer Bill Wallace said the objective of the engineering and design teams which fast-tracked it to market ahead of Tesla’s Model 3 was to make an excellent “B Class” (subcompact) car in its own right.
What that should add up to is this is an electric car with far more appeal than 80-110 mile range EVs it now towers over in the range-for-dollar metric.
Thanks to its relatively supersized 60 kWh battery, the Bolt has enough range that many drivers will not need to plug in to recharge every single day, and this buys peace of mind even in regions where charging is not as plentiful as in California, and other EV hotspots.
Mass-Appeal Tech Halo
Presentation of the Bolt as a symbol of a new GM on the edge of the technological frontier was mixed with mutually contradictory messages expressed and implied that this is a potential mainstream solution that may not sell in mainstream volumes.
On the positive side, engineers and marketers passed along the sentiment from the top that CEO Mary Barra lights up with enthusiasm in internal meetings when discussing what the Bolt means for the company and its positioning for the future.
As GM also announced this week an $85 million assembly plant with Honda for hydrogen fuel cells, it is posturing with its most advanced battery electric car to date – due in all 50 states by Q3 2017 – as competitive and a harbinger of more to come.
For many consumers who’ve bought plug-in electrified cars that now comprise 0.9 percent of the U.S. passenger car market, the Bolt is obviously a huge step forward. Hope is that the car will sell well above the just-over 30,000 unit record held by Nissan’s Leaf in 2014, even if GM’s marketing – underway with a slew of video spots – is only as effective as it was for the Volt.
Of the staged rollout, lead marketer Steve Majoros says this is necessary to ensure a quality dealer experience and to meet customer expectations. The company won’t estimate how many units it would like to sell, but as it takes its time to do things right, its people say their hope also is the Bolt will be well received, even capturing sales from buyers who weren’t necessarily thinking of going electric.
Great Spec Sheet
The Nissan Leaf has been the sales king in the sub-$40,000 price class, and while as Majoros noted real-world transaction prices for it are several thousand dollars less than what the Bolt is to sell for, many will see it as worth the stretch.
Of course a next-generation, longer-range 2018 Leaf is right around the corner, but for now the Bolt EV is much faster, more efficient, and with more than double the range.
Powering it is a proprietary motor with 200 horsepower (150 kW) and 266 pounds-feet of torque good for 0-60 mph times for the 3,580-pound car of 6.5 seconds – a relative hotrod next to the 10-second Leaf – or Toyota Prius hybrid or Prime plug-in hybrid.
Chevrolet will also offer over the air software updates as does Tesla now. How often or substantial these will be remains to be seen.
Like other EVs, it is a one-speeder – effectively working like an automatic transmission. Top speed is 92 mph at which point the motor validated at over 12,000 rpm is spinning at about 9,100 rpm.
Range at the top speed is not known – for those of you in Europe who’ll be getting an Opel Ampera-e, a rebadged Bolt exported from the Orion Township plant where they’re exclusively built. A misconception reported out there is range is 170 miles at 92 mph, but Chevrolet communications rep Fred Ligouri says that’s the range for sustained speed of 70 mph, not 92.
The flat in-floor battery adds rigidity to the structure. Ordinary propylene glycol coolant is routed through a cooling plate that regulates temperature for the 10 modules of 288 cells in 96 cell groups to a “chiller” and back. Wallace said the battery is field serviceable, though if ever bad cells are detected, it would mean a module replacement. Proprietary control software can accommodate old and new replacement battery modules, and even mildly different li-ion chemistries. The Volt saw four li-ion chemistries, for example, and things are always evolving.
Providing juice is a rigid, water- and vapor-tight 60-kWh battery. It’s thermally managed – heated and cooled – unlike the Leaf’s battery with which Nissan saved money by foregoing water cooling.
Level 1 (120-volt) charging adds four miles range per hour, or about 60 hours for a 238-mile refill. Level 2 (240-volt) via the 7.2-kW onboard charger adds about 25 miles per hour, or a complete charge in just over nine hours with the official $699 Aerovironment unit sold by Chevrolet, or EVSE of your choice.
About 11 components including the battery cells come from South Korea’s LG Chem and LG Electronics. Unlike Tesla, and potentially other manufacturers, GM’s $750 standalone DC fast charge option is limited to a nominal 50 kW.
This adds 90 miles range in 30 minutes to the pack, and critics have asked why GM would not offer quicker charging like Tesla does – or a public fast charging network like Tesla does – for those wishing to travel.
Apple co-founder Steve “Woz” Wozniak who recently got out of a Model S to get into a new Bolt however answered this objection in a comment under another Bolt review.
“Not mentioned is that this car works fine for road trips.” He said. “We took a test trip last week to Anaheim and back. I was surprised to discover how many DCQC’s (Quick Chargers) there were, 2,200 in the U.S., more sites than for Tesla Superchargers.”
It’s expected more DC fast chargers are coming too, the VW diesel emissions cheating settlement being one source that will enable GM cars to plug right in.
Chassis and Styling
Built with seven types of steel strategically placed plus aluminum for the door, front quarter panel, and hood skins, the Bolt rides on a proprietary chassis clean-sheet designed for this EV – and others that are to follow.
CEO Barra has said the Bolt EV is the company’s platform, not just for its autonomous drive efforts now underway, but for future electric cars as well.
Fitting with the “mainstream” appeal, Chevrolet says the car is stylistically meant to fit in to the family line, and not stick out like a screaming green-car statement as has Toyota’s Prius or Nissan’s Leaf.
Armchair pundits alternately find its utilitarian style to be contemporary and satisfying enough, or not as hip as Tesla’s planned Model 3 which may be in first customer’s hands by October, according to green car analyst, Alan Baum.
Left: rear portion of inside of Bolt’s chassis. Right shows front and firewall. Of the seven types of steel, five are high or ultra-high strength (including “press hardened”), one is mid-strength, one is mild strength.
The Bolt’s coefficient of drag is 0.308 – not 0.32 as reports bashed it as being last year – and otherwise better than the smaller Spark EV’s 0.326 and respectable for what is classified as a “small wagon.”
Unique details give it its own identity, and Wallace said it’s much more than a modified Sonic with fancy battery and motor, though a cost-savings mandate dictated some shared GM parts where feasible.
If anyone still has doubts, the Bolt comes with accoutrements expected of a car pushing just below and above $40,000.
At the business end, an 8-inch main instrument cluster is accompanied by a 10.2-inch infotainment screen with Apple CarPlay, Android Auto, plus OnStar 4G LTE with a Wi-Fi hotspot. Navigation is by OnStar turn by turn or your connected smartphone.
The Bolt by any measure is also a marvel of space utilization. Though it’s a subcompact on the outside, its 95 cubic feet passenger volume plus 16.9 cubic feet cargo volume is within the EPA’s 110-119 “midsized” scope. If it were classified as a sedan as the Leaf is, it would be midsized.
This is enabled by details like carved out seatbacks, but mainly thanks to the flat floor which let the designers optimize the five-seater to be roomier than the Volt. In fact, its 95 cubic feet total volume is a nominally above Tesla’s large-class 94-cubic feet volume Model S and Model X, though some of this is due to the Bolt’s high ceiling.
The 16.9 cubic-feet cargo volume with rear 60/40 bench seat back up is decent, and a stow-able false floor in back comes out to stash stuff, though there is no spare to replace a self-sealing 215/50-17 Michelin Energy Saver tire, if needed. With seat folded down, while the floor is not perfectly flat, room is enough to lie a large bicycle with front wheel removed or other largish objects thanks to the tall ceiling.
Larger size people may wish to test sit in the narrower than usual seats. Design lead Stuart Norris said engineers consciously made the inside bolster (away from the door) to be asymmetrically narrower in order to make room for a wider center console and armrest. This was deemed a good tradeoff as other cars of similar width dimensions have narrow and thin or no center armrests.
Front and rear seat occupants – of average dimensions to a few inches above six feet – ought to find the interior accommodating enough and the rear bench is wide enough for as many as three child seats to be installed. An available heated steering wheel, and heated front and back seats also add to the upscale feel, though lumbar support for the driver would have been appreciated.
Equipped with 10 air bags, the Bolt has safety and user friendliness baked in. The upscale Premier, as shown to the media, has a rear camera mirror replacing the standard rear camera, and a 360-degree Surround Vision system gives a bird’s eye view by stitching multiple camera images together. This system is handy for perfectly fitting within the lines at a parking lot, but the front and rear cameras have noticeably lower resolution than the side cameras that are located in the bottom of the side view mirrors. This leads to an oddly blocky overall look on the surround view image where these lower and higher resolution cameras are stitched together.
A squirter for windshield washer fluid – one fill location for convenience – is positioned to clean road dirt from the rear camera-mirror’s eye.
Other features optional on the LT, and standard on the Premier are Side Blind Zone Alert, Rear Park Assist and Cross-Traffic Alert. Also in place as part of a $1,000 option on the Premier car driven was GM’s Forward Collision Alert, Lane-Keep Assist with Lane Departure Warning and a Low-Speed Forward Automatic Braking plus Front Pedestrian Braking.
Bolting Down The Road
Putting the shift by wire system in D lets the very quiet motor propel the vehicle forward with effortless ease.
Chevrolet made better-than-average quickness a priority in its limited-market Spark EV with its up to 400-pounds-feet of torque in the 2014 model, and the Bolt follows through with the fun factor.
Stomping on the accelerator from a standstill will scuff the tires a bit though StabilTrak stability and traction control – which can be turned off – stops the rubber burn. Torque is enough that entering a highway from an on ramp at about 35 mph the front tires lit up for a brief spell.
With a top-speed of 92 mph, all the go-power is concentrated for legal and mildly extra-legal potential in the U.S. That makes sense when dealing with a single-speed transmission which sees energy losses go much higher when it winds to higher rpm.
Wallace said a multi-speed transmission might very well deliver efficiency gains, but per almost universal EV practice, that is off the table, as is for now all-wheel-drive, though the chassis is capable of handling a rear motor drive. Another rep on hand said “we shall see” whether GM ever rolls that out, but the primary goal for now was to stay lower on the cost scale.
Ride quality is within limits of normalcy, though on rough roads a somewhat firmly sprung MacPherson front, torsion beam rear suspension lets potholes and bumps be felt more than in a longer wheelbase car tuned to the plusher side of things.
Would you like a bigger battery? It’s not believed the Bolt’s battery form factor is able to squeeze much, if any more cells in, and no word of modular batteries a la Tesla has been mentioned.
On some uneven pavement, a mild fore-aft seesaw effect was noticeable, but overall, the vehicle is well controlled, and the ballast of a 960-pound battery in the floor offers exceptionally low center of gravity and poise.
So, is this a “hot hatch? No. Not if max-velocity cornering or lap times are part of the formula, though the 6.5-second 0-60 and 2.9-second 0-30 times are quick and within realm of some cars positioned as performance models.
Corner carving otherwise is enjoyable, if not scintillating, and if one wanted to amp up this a bit, grippier tires than the low rolling resistance rubber could be had on the aftermarket, at the expense of some range.
Speaking of which, while we did not have opportunity to run the car out of power, its range is known to be within spec for the 238 mile EPA estimate. The EPA certification is conservatively based on the D setting, and while Chevrolet will not estimate a non-official number, this means maximizing regenerative braking makes more range possible.
And for that, Chevrolet has your best interests in mind. That is, it innovated beyond competitive EVs like the BMW i3 which utilize a lot of regenerative braking with the Bolt’s L shifter setting. This allows “one-pedal driving” as Chevrolet calls it, and will bring the Bolt to a complete stop. Actually, the system uses some motor torque to hold the car at a complete stop, and otherwise lives up to its name and is quite novel.
With this capability, the driver need rarely touch the brake pedal and it opens up a whole new experience that seems welcome and makes sense.
A left-side mounted paddle – like a paddle shifter in a sports car – also lets the driver feed more regenerative braking in, adding to the ability to focus on the go pedal. Of course a brake pedal is in place, usable – necessary on quicker stops – and feel is OK.
Using regen from any of the possible ways – ordinary coasting in D, deceleration in L, and via the paddle make the drive experience unique. With up to 70 kW of regen energy being returned to the battery, range is definitely extendable and adds to an effect akin to trickling gas back into a tank, as it were.
Of course internal combustion vehicles do not add gasoline to their tanks on the fly, so this is an elegant solution EVs offer that conventional cars do not.
And, it can be an entertaining solution too, as it becomes a game to add miles to the range-o-meter which uses algorithms to estimate how far you have to go based on load draw and it learns and adjusts to the driver’s habits also.
Mass Market Ready
The Bolt EV folds in lessons learned from the Volt, Spark EV, and other electrified vehicles and promises a well-sorted car.
GM notes out of over 100,000 Volts sold, no battery has needed to be replaced under the degradation warranty. Its cells are “pharmaceutical grade” with only two problems per million, and the Bolt is positioned as a pure EV to take things from there.
Volt and Bolt parked at the Henry House, a modern sustainably built green home in Portola Valley near Palo Alto owned by one of the first three buyers of the Bolt. (See also top photo.)
But while the engineers are genuinely proud of the product, the Bolt is the first of a field that will include the Model 3, and next Leaf. Hyundai and Kia are also planning 200-mile EVs in a year or so, Ford will have one later this decade, as will VW, and well, there will be more to come.
The Bolt is first in the 200-plus miles for under $40,000 club, but won’t long be the only. This is now more true with a rollout schedule that won’t see some U.S. states getting customer deliveries until mid-year and even to September, and by then the Tesla Model 3 hoopla may be in full swing for its fans, and 400,000-plus intenders.
Analyst Alan Baum’s first-year Bolt sales estimate factoring variables including its new tech versus new vehicles on the horizon plus other realities such as Chevrolet’s plug-in marketing track record, is 21,000 units in 2017. That’s about 3,700 less than the second-gen Volt did last year, but once the Bolt is fully for sale in 50 states, how might it do in 2018, you ask? Baum estimates 25,000 Bolt sales.
As a further counterpoint however, GM is quietly confident and has under promised and over delivered on a few things, not least being the range. Its quality control is also likely to be quite high, whereas Tesla has seen a number of QC issues including replaced drive motors in the Model S, and myriad glitches in the Model X.
Tesla’s chief challenge is to improve manufacturing processes – something Elon Musk has promised will happen – but meanwhile the Bolt, while maybe more perceptibly plain, offers a lot. Now.
Its maker, with something to prove, is furthermore prepared to back up the emblem of its technological credentials with white glove customer service just like Volt and Cadillac buyers already enjoy.
Our summation? As we said to head marketer Majoros – who offered a mild nod of acknowledgment – if the Bolt were a BMW product, it might break any glass ceiling that’s existed until now on EV sales.
Chevrolet’s policy is however not to boast as it’s still coming out from under the shadow of its past, and it’s been stung by too-ambitious projections before. That was for the Volt introduced for 2011 which by all accounts has been underappreciated by the general public, yet loved by many, if not all, who’ve driven and known the car.
So, the new EV with a bowtie badge may thus be in a similar boat. The expectation of high quality and a satisfactory value proposition is what Chevrolet is saying between the lines, and until proven otherwise, we see no reason not to believe it.
In fact, until it is fully known what other carmakers bring to market this year and next, the Bolt may be the best EV value for the dollar that anyone can buy.
Honda and General Motors are taking a step forward on hydrogen-powered cars together, announcing an $85 million investment into hydrogen fuel cell stack production at a plant in Michigan.
GM’s Brownstown Township plant in Michigan will produce the fuel cell equipment, starting around 2020, under the name of the joint venture, Fuel Cell System Manufacturing (FCSM). The project will create 100 new jobs according to the automakers, which share an equal investment in the new venture.
The fuel cell stacks being built will find their way into next-generation hydrogen fuel cell vehicles starting around 2020, and will be shipped to other factories where they will be installed into the vehicles. When the new fuel cell system is ready, it will be deployed in two separate vehicles, one from each automaker.
GM and Honda first joined forces on hydrogen back in 2013, looking for ways to cut development costs while achieving their goals of lighter, smaller, more powerful and less expensive fuel cell stacks.
The FCSM will have a board of directors consisting of three executives from each company and a rotating chairperson.
“With the next-generation fuel cell system, GM and Honda are making a dramatic step toward lower cost, higher-volume fuel cell systems. Precious metals have been reduced dramatically and a fully cross-functional team is developing advanced manufacturing processes simultaneously with advances in the design,” said Charlie Freese, GM executive director of Global Fuel Cell Business. “The result is a lower-cost system that is a fraction of the size and mass.”
Honda is currently selling a hydrogen powered vehicle, the Clarity, which went on sale in December of 2016.
The article went on to quote him as saying the car’s coefficient of drag was measured at .32 versus the Toyota Prius with a Cd of just .24.
Stuart Norris, the managing director of design for GM South Korea, had actually been referring in that article to the general category of squat and wedge-shaped hatchbacks as being “a disaster” but some news accounts reporting the Automotive News interview implied that he was referring specifically to the Bolt EV itself.
Car and Driver magazine then published a detailed review of the Bolt in its October 2016 issue in which a road test showed the car could drive a surprising 190 miles with cruise control set to 75 mph and climate controls set to 72 degrees.
How could this be?
We now know at least one part of what enabled the Bolt’s unexpectedly good highway range.
In an interview last week, Norris said the .32 coefficient quoted by Automotive News last summer was actually the original engineering design target for the car rather than the final measured result.
When pre-production prototypes were revealed in January 2016 the wind tunnel testing was coming in at .312, as Car and Driver magazine reported at the time. With the final production headlight lenses and other exterior parts in place on the car it has since fallen to .308.
Coefficient of drag combined with a car’s width and height describes its resistance to being pushed through the air. Drag has an adverse effect on efficiency as vehicle speeds increase so it does not matter much in city driving but does play an increasing role at higher speeds.
Other factors like powertrain design also play a role in good highway efficiency. For example, the Bolt’s large 60 kWh battery may allow it to more efficiently discharge the power levels needed to maintain faster highway speeds where a smaller battery might struggle a bit. In addition, the Bolt’s motor is also geared to run at a relatively slower rpm at highway speeds than some other electric cars.
According to Norris, computer analysis guides the design process but final surface shape optimizations are done with physical models and wind testing.
He said the Bolt EV was put through 6 full-scale rounds in GM’s wind tunnel to optimize its slipperiness and counterbalance the inherent drag of its space-efficient utilitarian shape. Typical car designs may see the wind tunnel 4 times or less, he said, but even conventional gasoline-powered cars are getting increasing attention now as companies stretch to meet regulatory fleet mileage goals.