Chevrolet Volt


Debut: 2015
Maker: General Motors
Predecessor: Volt Mk1 (2010)



 Published on 22 Sep 2015 All rights reserved. 


According to the original plan revealed at its launch in 2010, General Motors should have already delivered 170,000 copies of Volt Mk1 by this time. Unfortunately, the plug-in hybrid car (or range-extending EV, as insisted by GM) has been proved less popular than expected, with only 77,000 units sold to date. This means the second generation needs to work harder.

From its exterior, you can already see GM has made quite a lot of changes. Its body gets much sleeker, with a roof line flowing smoothly from the nose to the hatchback tail. The front end design is perhaps too flashy and not as tasteful as the old car's, but meanwhile, it has ditched the gimmicky black stripes at the top of the doors. You might say the whole exterior design now gets closer to conventional cars, but that is perhaps something GM did deliberately after consulting the successful story of Tesla Model S.

A bit disappointing though, despite of the streamline shape, its drag coefficient is unchanged at 0.28. It should have been lower.



While Tesla can afford an all-new platform dedicated to EV architecture, the mainstream Volt has to keep production costs under close guard. That's why the Mk2 is still derived from the Delta II platform of the conventional Opel Astra / Buick Verrano and Chevrolet Cruze. It gets slightly larger – wheelbase is stretched by 10 mm to 2695 mm; Length and width are up by 85 and 20 mm, respectively. Only the roof is lowered, yet by merely 5 mm. Sadly, all measurements of passenger space are virtually unchanged from the old car. The only exception is the rear seat, which has been converted from 2 individual seats to a bench seat. Nevertheless, as the T-shape battery still occupies a large part of the central tunnel, the middle rear seat is best reserved for emergency use.

Up front, the new interior looks remarkably different from the old car. Bascially, its architecture gets closer to the mainstream Opel and Buick, with the exception of twin-LCD, one occupies the instrument pod and another at the floating panel above the center console. Both of them are quite large at 8-inch. Underneath the console screen is now the controls for air con and ventilation. It answers one of the criticisms of the old car, i.e. drivers need to use the touchscreen to adjust HVAC. In short, the new cabin trades Sci-Fi theme for practicality and cost sharing.



Despite of the larger dimensions, the new Volt is 105 kg lighter than the old car. This must thanks to the use of more high-strength steel, aluminum bonnet and tailgate as well as improvement to its battery and powertrains.

The lithium-ion battery pack now offers 18.4 kWh instead of 17.1 kWh of usable energy (note: the battery of Mk1 was originally rated at 16kWh, then gradually improved). It is made up of 192 cells, a third fewer than before, so to cut 14 kg of weight, reduce costs and enhance reliability.

The petrol range-extender engine has been changed from the old 1.4 Ecotec iron-block unit to a new 1.5-liter Ecotec all-alloy unit with direct injection, variable cam phasing and on-demand oil pump. Its output is lifted from 84 to 101 hp. We don't care about its torque output as it rarely drives the wheels. Its main mission is to recharge the battery when the latter depletes.

The Voltec II electric powertrain is also improved. Previously, it employed a large motor for propulsion and a small motor primarily for generation. Now it employs 2 motors of closer sizes, and they can provide propulsion together. Total output is unchanged at 149 hp, but maximum torque is improved from 273 to 294 lbft, while efficiency is enhanced by 12 percent. Moreover, the motor/transmission unit and smaller power electronics shave 45 kg. The motors are integrated with the planetary CVT and differential in the front transaxle. Front-to-rear weight distribution is 60:40, much like a conventional FF car.



According to early road tests conducted by C&D and MT, the new car is about 1.5 seconds faster to accelerate from 0-60 mph, taking less than 8 second now. In other words, it’s fast enough for most consumers. Top speed is limited to 98 mph, but a BMW i3 is 5 mph slower still.

GM claims it will travel 53 miles before the range extending engine fires up, up from 35 miles of the original Volt. This means 90 percent trips of its typical owners can be accomplished without burning a single drop of oil. When the gas engine kicks in, the EPA fuel economy is still a good 42 mpg combined, thanks to the engine that always works in Atkinson combustion cycle. With a full tank of fuel, the total range is extended to 420 miles.

In urban driving, the performance feels lively as the electric motors offer good torque at low speed. As expected, the driving experience is extremely calm and relaxed as the electric motors make so little noise and no vibration at all. The suspension is markedly improved from the old car’s, being more composed over undulations. Another big improvement is the brakes, whose pedal feel is linear and natural, unlike many hybrids or EVs with regenerative braking. The new car turns into corner more responsively, too. However, it is still no driver’s car. Push it beyond the rather low grip levels of its Michelin energy-saving tires and it will run into terminal understeer.


When the petrol motor kicks in, the Volt becomes less impressive. Not only the noise is quite intrusive after you have got accustomed to the serene environment, but the engine rev and noise are oddly irrelevant to the speed of the car. There is no mechanical connection between the four-cylinder and the front wheels, remember.

After the first generation Volt, the Mk2 no longer sounds ground-breaking. However, its technology definitely gets more matured and better suited to mainstream production. It is not only more practical to use in all aspects but also gets cheaper. The base price is US$34,000 at its home market. Factor in federal tax break and it becomes just $26,500. In California it is slightly cheaper still. With the arrival of Volt II, plug-in hybrid cars are finally a practical choice for ordinary consumers. The next generation Toyota Prius had better to be good, because it no longer enjoys any cost advantages against the Chevrolet.

Verdict: 
Specifications





Year
Layout
Chassis
Body
Length / width / height
Wheelbase
Engine

Capacity
Valve gears
Induction
Other engine features
Max power
Max torque
Transmission
Suspension layout

Suspension features
Tires
Kerb weight
Top speed
0-60 mph (sec)
0-100 mph (sec)
Volt
2015
Front-engined, FWD
Steel monocoque
Mainly steel + aluminum
4582 / 1808 / 1433 mm
2695 mm
Inline-4, Atkinson-cycle + electric motor
1490 cc
DOHC 16 valves, DVVT
-
DI
149 hp (engine: 101 hp)
294 lbft (engine: 103 lbft)
CVT
F: strut
R: torsion-beam
-
205/50HR17
1607 kg
98 mph (limited)
8.4 (c) / 7.8*
23.4*




















































Performance tested by: *C&D





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