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lundi 4 décembre 2017

THE AUTOMOBILE 2.0: CHEVROLET BOLT EV PREMIER VS NISSAN LEAF SL VS TESLA MODEL 3 LONG RANGE


The first comparison test of the practical electric car

Can I see a show of hands for all of the Tesla Model 3 reservation holders out there? Now drop your hand if you’re put off when I tell you that the one Motor Trend tested is a big-battery ($9,000), “premium features” ($5,000) Long Range version that stickers for $60,500. Mostly shrugged shoulders? You know how Tesla rolls, then. Although the base price on the window sticker in fact reads “$36,000,” we get the loaded version to test. Just like any premium automaker, the high-profit versions get delivered first.

Now how about everybody who is serious about plunging into a long-range electric car but doesn’t have the stomach for Tesla’s financial roller coaster? Quite a few. That means you’re picking between two other recent entrants: the 238-mile Chevrolet Bolt EV (last year’s Motor Trend Car of the Year) or the redesigned, 150-mile Nissan Leaf—both of which we’re comparing here to the Model 3. By the way, any of you buying the Chevy or Nissan with profit you made off of Tesla stock? Just kidding. Sort of.
I’ve been covering electric cars for so long that I once pushed a stone-dead General Motors EV1 down a street. There have been plenty of “firsts” in this rapidly evolving segment. But this exclusive comparison—the Model 3, the second-gen Leaf, and the Bolt—matters because it’s a milestone. This is the first time anyone has tested and compared three electric vehicles that really could be your affordable, everyday, one-and-only car. With ranges of 150 to 310 miles and stripper-version base prices from $37,495 to $36,000 before federal and local incentives, they’re full-fledged, meat-of-the-market automobiles. And Tesla’s global Supercharger network is 7,320 (and counting) nails in the coffin of the argument that an EV can’t replace your gas-gulping jalopy as your road trip car of choice.
To help with evaluating our exclusive gathering, we brought in some veteran co-conspirators of all things electric. Patrick Hong has a 23-career testing cars (including that same GM EV1) and carries degrees in both mechanical and aerospace engineering. Alec Brooks is a seminal figure in the history of the modern electric car, having led the development of the GM Impact, predecessor of the EV1, and run the development of the of the tzero electric sports car, which was the inspiration for Tesla’s Roadster.
As if there weren’t enough built-in tension already in this test, Hong rolls a grenade into the big picture takeaway from the comparison: “Comparing this Model 3 to the Bolt and Leaf isn’t fair—like comparing a BMW 3 Series with a Camry or Accord.”
It’s an awkward setup, yes. As with any head-to-head test, you just have to weigh whether extra features and qualities seem worth their price. And although we’ll get to the “How do they drive?” part soon, we’ll start with a more fundamental comparison: how people fit. After all, if this is your everyday car, you’re likely going to have passengers.
Hong thought the Tesla’s back seat is roomy enough but “felt a little sunken in, without much forward vision.” As for seat comfort in general, Brooks found the Tesla’s and Leaf’s front seats more comfortable than the Bolt’s—the Chevy’s bottom cushion is too narrow; its little side bolsters cut into his thighs.
Brooks then examined the trade-off of the Tesla’s sweeping glass roof, which maximizes headroom but at the expense of some sunload during daytime driving: “The glass was noticeably warm when the car was sitting in the sun. Access to the rear seats isn’t as good as the Leaf and Bolt due to the low seating position and substantial sills.” Of the two hatchbacks, the Bolt gets the rear passenger’s thumb-up for better foot space beneath the front row.
And thus we’ve tripped over the slow-unfolding evolution of the electric car’s architecture and how it affects its human cargo. Take a look at the three cars’ seating profiles.

Having batteries slabbed beneath the floor might be great for lowering the cars’ center of gravity for handling purposes, but it pinches headroom. No big deal for the Bolt and Leaf silhouettes, which are as draggy as coral reefs anyway (Cd’s of 0.31 and 0.28, respectively). They just go taller. As such, Hong found the Bolt’s back seats to be roomy with a stadium-seating configuration.
But the Model 3’s lower, sloping profile is reaching for slicker aerodynamics (0.23) resulting in some unusual consequences in back: a roof crossmember forward of the rear passenger’s heads allows for a headroom-maximizing thin sheath of glass directly above their noggins. Simultaneously, their knees are noticeably raised due to the smallish difference between foot and hip heights. Still, it’s worth noting that on paper, at least, the Model 3’s traditional SAE rear dimensions are quite similar to those of the BMW 330i.
The thing is, Tesla’s compromised back seat gives the direct payoff of less drag, leading to more efficient battery use. Despite being 400 pounds heavier than the Leaf and 350 more than the Bolt, the Model 3’s combined mpg-e is 6 percent higher than the Chevrolet and 13 percent better than the Leaf.
Equating the consumption of electricity to fossil fuels is dubious, but EVs are extremely efficient. The value of the Model 3’s better aerodynamics is evident in its highway mpg-e.
Now to a driving dynamic unique to EVs: “One pedal driving”—as in, not having to touch the brake pedal to slow down. As you lift your foot off the accelerator pedal, the electric motor furiously captures kinetic energy (giving some charge back to the battery) while slowing the car. Think of it like super strong engine braking that can substitute for light braking situations. Nissan has even branded its feature as “E-pedal,” and it’s pretty cool. Particularly in that it automatically interweaves friction braking if the battery is too full or when coming to a full stop (no need to hold the brake while paused on a hill).
During our tests, the Bolt and Leaf similarly lift-pedal decelerated, though the Chevrolet’s can be further intensified and fine-tuned by squeezing a steering wheel paddle. By comparison, the Model 3’s regen deceleration is more of a speed corrector; the brake pedal is needed for real slowing and absolutely required to come to a halt, as regen vanishes at about 4 mph.
Most EV drivers quickly find that slowing for traffic or corners by simply lifting their right foot is a really cool way to drive. The Bolt wins this debate with a steep slope, decelerating to zero mph and having a hand paddle to fine-tune it. A plus for the Leaf’s “e-pedal” is that it seamlessly employs its friction brakes when the battery’s close to full and there’s no capacity left to fill. The Tesla has selectable profiles but still requires friction brakes to stop.
Brooks felt rather strongly about how the Tesla system works (or doesn’t): “It’s not strong enough to slow the car for normal corners—you have to constantly move your foot to the brake pedal. From my experience, I know firsthand that strong regen and rear-wheel drive don’t always play well together.”
When it is necessary to use the brake pedal in an electric car, it often is a shotgun wedding of friction braking and regen deceleration. And the words we often use to describe it are “nonlinearity,” or more poetically, “fishiness.”
Regenerative brakes recoup some of the kinetic energy otherwise lost to brake heat. Try that with an internal combustion engine! The trouble is that at higher stopping rates, regen and friction braking must be combined, and not always very artfully. Here, we’ve accumulated data from several stops, measuring both brake pedal travel and foot force versus stopping rate. Things to look for: A fuzzy plot means an indistinct response, and the straighter the line, the more predictable it is. Favorite? The Model 3. The Bolt’s effort is mushy; the Leaf’s travel has too much initial play.
Depicted as data, it’s recognizable as that fuzziness in the Bolt’s nearby plot of pedal force versus stopping g’s. It suggests an indistinct initial feel—that rather uncertain sensation in the car’s braking feedback. The Leaf’s effort is light and there’s a lot of free motion when you step into the pedal. The Model 3’s pedal doesn’t move much, but its 1.00g stopping rate signals why it was the shortest stopper in our emergency, 60–0-mph brake test.
Where are the more familiar performance numbers, you ask? They’re next. Just know, as we embark on an electric future, charts like these are going to be increasingly important. But to satisfy the old-school folks, here are the ones that matter when chatting with your friends.
0–60: The Model 3 buries the other two. It takes 4.8 seconds to hit 60 mph versus the Bolt’s 6.3 and the Leaf’s 7.5. As for entering a long freeway on-ramp, the Tesla’s quarter-mile time was 13.4 seconds at 104.9 mph, whereas the Bolt’s was 14.9 at 92.9, and the Leaf’s was 15.8 at 87.6 mph.

In terms of handling, it’s a blowout. At Hyundai’s winding track handling venue, the Bolt was pointy and nimble, but the Leaf felt softer, less powerful, and nose-heavy. The Model 3? It handled like a four-door Porsche Cayman (albeit loaded with luggage).
“I thought the Model 3’s handling felt terrific, and its rear-wheel drive was noticeable by its lack of steering drama on hard acceleration,” Brooks said. Added Hong: “The Leaf understeered heavily on the track, and its chassis felt dated.”
So why can’t Chevy and Nissan simply make their electric cars handle better? With very few exceptions, firming up a car’s handling means that ride comfort gets harsh and uncomfortable. One feature of Hyundai’s Proving Ground is a reproduction of some infamous Southern California freeway surfaces—all of which we traversed at 70 mph while logging the driver seat’s vertical acceleration and the noise levels in the front row.  Although there are striking differences, each car’s ride is actually good if it fits your taste and expectations. The Leaf is great if you like downtown L.A. pothole compliance; the Model 3 is perfect if your commute is paved like the Nürburgring. Swap audiences and preferences, and both will feel terrible.
Another central characteristic of electric vehicles is the major influence on ride quality caused by battery weight. What’s going on in the three ride quality graphs below? An accelerometer helped measure the driver’s seat’s vertical accelerations over the same 5,400 feet of an aggressively bumpy stretch of test track. That raw data was interpreted into what’s akin to the frequency bands of a sound system’s equalizer. There are two peaks of note—one at about 2 hertz, which is the springs’ natural frequency, and another between 6 and 7 Hz, which is vibration from the wheel’s motions. What’s notable? The Leaf has the calmest ride and is also the quietest (see figures at bottom) Meanwhile, the Bolt EV heaves a lot on its springs; the Tesla doesn’t but shows a lot of higher-frequency input from its wheels and tires.
As for autonomous-driving features, Tesla is not alone in edging EV drivers ever closer to a hands-free world. Longer term, the emergence of autonomous systems in electric cars means the battery will support the heavy power loads of self-driving’s computing and multiple sensors, and the awareness of its driving environment will stretch the batteries’ range and strategize the car’s navigation into the charging infrastructure.
When I originally sampled Nissan’s ProPilot Assist in Japan, I half wondered if it was just the jetlag. This thing seemed better than good. But upon returning to home soil, I felt the same reassurance when I tried the system in Detroit and now again after using it for several days in California’s high desert.
ProPilot Assist is outwardly quite simple—a single video camera, a solitary radar. But for single-lane driving, adaptive cruise control, and lane centering, it’s freakishly adept at centering itself between the lane stripes. It needs only a light hold on the steering rim—its hand detection is impressively sensitive.

How does it compare to the Model 3’s Autopilot?
Autopilot 2 is a suite of sensors (notoriously sans lidar)—configured with software to do (at the moment) about the same job as ProPilot, plus auto lane changing. Except it does it less well. But those pairs of extra video cameras on the Model 3’s flanks—paused, waiting to see the world—will they be the eyes of the first privately owned Level 4 car? That’s the promise.
Present day, Tesla’s autosteering tended to hug the left side of the lane. “ProPilot Assist was more fluid, though it was sometimes confused in the dark with dim lane markings or strong opposing headlights,” Hong noted.
Added Brooks: “The Tesla seemed to enter freeway turns well after a human driver would. At one point, it chose to drive over the Botts’ dots on the left edge of the lane for a good 20 to 30 seconds. ProPilot steered into curves without any lag—just like a driver would.”
We mentioned these irregularities to Tesla. The response was that its test vehicle was a preproduction vehicle and still being fine-tuned. No opportunity was given for a retest.
Which gets us to the issue of the screen. Tesla has incorporated nearly everything having to do with driving the car into its giant center touchscreen. Its nerviness to go all in on a total touchscreen interface is breathtaking.

THE WINNER

So which car is our pick?

Brooks: “The Bolt—despite its seats and the hard-to-manage infotainment system. My return trip was over Angeles Forest/Angeles Crest highways, and that drive reinforced my thinking. Slowing for a corner was as simple as lifting off the accelerator and holding the steering wheel paddle. No need to constantly be shifting back and forth between pedals. It’s a real demonstration of the driving experience available that’s possible with electric propulsion.
“The Leaf’s display seemed about 10 years behind Tesla’s for resolution and fluidity of operation. But the second-gen Leaf is a substantial improvement in most areas—it’s very easy to drive, and the steering has good feel. When it gets the bigger 60-kW-hr battery pack, it will be a credible Bolt alternative. But for many people, having only two-thirds of the Bolt’s range may not cut it.”

Hong is a Bolt fan, too, but thought better of the Leaf: “Good exterior styling but an outdated, if well-finished, interior. They seemed to be cramming a new, smallish screen into a traditional instrument panel. Its lack of range was really apparent in this test, but if you’re a lower-mileage driver, it’s a heck of a deal.”
But the Leaf’s range still is a deal breaker for many. Such is the world we live in: We have gasoline cars with roughly 350-mile ranges because that’s what makes us comfortable. And EVs are no exception—especially with fewer places to recharge and a longer time commitment required to do so.

As for me, it’s about more than a couple of check box attributes, such as 310 miles of range or the existing Supercharger network. In broad-brush, the Bolt and Leaf are great cars but leaned-back EVs; they seem pushed onto the stage, hesitant in their groundbreaking roles. The Model 3 leans into the future with a reckless glee you cannot avoid noticing. Its infotainment and autonomous systems are still a work in progress, but new software features are being beamed in seemingly every night. Its Autopilot 2 is crazy ambitious; will it work without lidar? Electric cars are often dismissed for seeming soulless; the Tesla fills the void with human fantasies. You may need to talk yourself into a Bolt or a Leaf; you need to talk yourself out of paying the premium for this Model 3.
Taking all these factors into consideration, our finishing order in this first-ever comparison test of affordable long-range electric vehicles: Tesla Model 3 first, then the Chevrolet Bolt and Nissan Leaf. True, this is a $60,500 Model 3—but some say magic is priceless. Hey, Tesla fans, are your hands still up?
2017 Chevrolet Bolt EV Premier2018 Nissan Leaf SL2017 Tesla Model 3
DRIVETRAIN LAYOUTFront-motor, FWDFront-motor, FWDRear-motor, RWD
MOTOR TYPEPermanent-magnet AC synchronous electricPermanent-magnet AC synchronous electricPermanent-magnet AC synchronous electric
BATTERY TYPELithium-ionLithium-ionLithium-ion
POWER (SAE NET)200 hp*147 hp @ 3,283 rpm271 hp
TORQUE (SAE NET)266 lb-ft @ 0 rpm*236 lb-ft @ 0 rpm307 lb-ft @ 0 rpm
WEIGHT TO POWER17.8 lb/hp23.8 lb/hp14.4 lb/hp
TRANSMISSION1-speed automatic1-speed automatic1-speed automatic
AXLE RATIO7.05:18.19:19.00:1
SUSPENSION, FRONT; REARStruts, coil springs, anti-roll bar; torsion beam, coil springsStruts, coil springs, anti-roll bar; torsion beam, coil springsMultilink, coil springs, anti-roll bar; multilink, coil springs, anti-roll bar
STEERING RATIO16.8:114.9:110.3:1
TURNS LOCK-TO-LOCK2.92.62.0
BRAKES, F; R10.9-in vented disc; 10.4-in disc, ABS11.1-in vented disc; 11.5-in disc, ABS12.6-in vented disc; 13.2-in vented disc, ABS
WHEELS6.5 x 17-in cast aluminum6.5 x 17-in cast aluminum8.5 x 19-in cast aluminum
TIRES215/50R17 91H (M+S) Michelin Energy Saver A/S215/50R17 90V (M+S) Michelin Energy Saver A/S235/40R19 96W (M+S) Continental ProContact RX
DIMENSIONS
WHEELBASE102.4106.3 in113.2 in
TRACK, F/R59.1/59.1 in60.6/61.2 in62.2/62.2 in
LENGTH x WIDTH x HEIGHT164.0 x 69.5 x 62.8 in176.4 x 70.5 x 61.4 in184.8 x 72.8 x 56.8 in
TURNING CIRCLE35.4 ft36.1 ft38.1 ft
CURB WEIGHT3,555 lb3,503 lb3,902 lb
WEIGHT DIST, F/R56/44%58/42%48/52%
SEATING CAPACITY555
HEADROOM, F/R39.7/37.9 in41.2/37.2 in40.3/37.7 in
LEGROOM, F/R41.6/36.5 in42.1/33.5 in42.7/35.2 in
SHOULDER ROOM, F/R54.6/52.8 in54.3/52.5 in56.3/54.0 in
CARGO VOL BEH F/R56.6/16.9 cu ft30.0/23.6 cu ft—/14.6 cu ft
TEST DATA
ACCELERATION TO MPH
0-302.6 sec2.7 sec2.1 sec
0-403.63.92.9
0-504.85.53.7
0-606.37.54.8
0-708.19.96.1
0-8010.313.07.7
0-9013.016.99.6
0-10012.0
PASSING, 45-65 MPH3.04.02.1
QUARTER MILE14.9 sec @ 92.9 mph15.8 sec @ 87.6 mph13.4 sec @ 104.9 mph
BRAKING, 60-0 MPH128 ft129 ft119 ft
LATERAL ACCELERATION0.78 g (avg)0.76 g (avg)0.87 g (avg)
MT FIGURE EIGHT27.4 sec @ 0.63 g (avg)27.9 sec @ 0.61 g (avg)25.7 sec @ 0.74 g (avg)
CONSUMER INFO
BASE PRICE$41,780†$37,085†$36,000†
PRICE AS TESTED$43,905†$37,915†$60,500†
STABILITY/TRACTION CONTROLYes/YesYes/YesYes/Yes
AIRBAGS10: Dual front, f/r side, f/r curtain, front knee6: Dual front, front side, f/r curtain8: Dual front, front side, f/r curtain, front knee
BASIC WARRANTY3 yrs/36,000 miles3 yrs/36,000 miles4 yrs/50,000 miles
POWERTRAIN WARRANTY8 yrs/100,000 miles8 yrs/100,000 miles8 years/120,000 miles
ROADSIDE ASSISTANCE8 yrs/100,000 miles3 yrs/36,000 miles4 yrs/50,000 miles
BATTERY CAPACITY60 kW-hrs40 kW-hrs75 kW-hrs
BATTERY CHARGE TIME (L2)/RATE9.3 hr/7.2 kW8.8 hr/6.6 kW8.5 hr/11.5 kW (est)
EQUA REAL MPG, CITY/HWY/COMB118/128/121 mpg-eNot tested90/128/104 mpg-e
EPA CITY/HWY/COMB ECON128/110/119 mpg-e130/106/118 mpg-e (est)131/120/126 mpg-e
EQUA ENERGY CONS, CITY/HWY28.6/26.3 kW-hrs/100 milesNot tested37.5/26.2 kW-hrs/100 miles
EPA ENERGY CONS, CITY/HWY26/31 kW-hrs/100 miles26/32 kW-hrs/100 miles (est)26/28 kW-hrs/100 miles
CO2 EMISSIONS, COMB0.00 lb/mile (at vehicle)0.00 lb/mile (at vehicle)0.00 lb/mile (at vehicle)
RECOMMENDED FUEL(240-volt) Level 2 or (480-volt) Level 3 electricity(240-volt) Level 2 or (480-volt) Level 3 electricity(240-volt) Level 2 or (480-volt) Level 3 electricity
* SAE certified
† BEFORE APPLICABLE TAX REBATES

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