Sunday, May 18, 2008
GM checks off milestones in the development of its gasoline-electric plug-in vehicle.
General Motors is developing the Chevrolet Volt electric vehicle and its lithium-ion battery pack on parallel paths—and both have passed significant milestones en route to a targeted November 2010 launch.
Larry Burns, GM vice president of research and development and strategic planning, tells Car and Driver in an interview that the design of the car has been frozen. While the production model is not a twin of the Volt concept, the more conventional sedan bears a family resemblance to the Chevy Malibu. And, in the interests of speed, it dips into parts bins of existing GM products wherever possible. That likely includes an existing four-cylinder gasoline engine as the on-board means of recharging the battery that, alone, gives the vehicle a range of only 40 miles.
The car was designed around the need to package a battery pack with a 150,000-mile life, with enough performance for a 0-to-60 mph time of 8.5 seconds. The Volt concept also underwent changes to improve aerodynamics after extensive wind-tunnel testing.
Time to Hit the Road
And at an event in Detroit, GM execs discussed preparations for road-testing the lithium-ion batteries that will go into the production car—past tests were with nickel-metal hydride batteries. The next stage of testing begins this month, with battery packs in a 2001 Chevy Malibu mule to gather much-needed durability data as the team scrambles to simulate 10 years of usage over the next two.
Burns says initially GM canvassed numerous battery suppliers around the world as part of its e-flex program. After a “bake-off” between suppliers, GM is working with two deemed to “have the chemistries to get there.” Burns says there are eight criteria that GM determined its lithium-ion batteries must meet for automotive application, including such things as energy density, extreme temperature viability, the material set, and cost.
The Volt will qualify as a PZEV (partial zero-emissions vehicle) and there will be an E85 ULEV (ultra-low emissions vehicle), but there are no plans for a diesel, execs said this week.
Second-Gen Work Underway
Meanwhile, Burns says work is already underway on the second generation. He declines to give a timeframe.
Plug-ins may be exciting, but with a range of only 40 miles, they fall short in comparison to a family-size fuel-cell vehicle with a 300-mile range and zero emissions. Burns sees work on plug-ins as a complimentary play to FCVs that convert hydrogen to electricity onboard, with batteries for power assist and to store energy regenerated in braking.
And he doesn’t anticipate the Chevy Tahoe or other full-size vehicles—or even minivans, wagons or mid-size SUVs—will be offered as plug-ins. “It’s okay for a Cobalt-sized vehicle, but not something with twice the mass.” For larger vehicles, GM’s two-mode hybrid system makes more sense. And efficient gasoline engines will continue to play a significant role in the future, Burns says.
GM Determined to be Fuel-Cell Vehicle Leader
And while the Volt program has been designated a number-one priority at GM, fuel-cell-vehicle development is running full steam as well, Burns says, because GM is determined not to repeat with FCVs what happened with hybrids, with Toyota getting so far out in front of the market. “Toyota creamed us on the Prius,” Burns says. “It won’t happen again.”
Pole-dancing? Audi’s next lightweight supermodel might be a bit more of a stripper.
The Audi R8 is great. But as evidenced by the R8 V-12 TDI (nee R8 TDI Le Mans) concept car on display at this year’s Detroit and Geneva auto shows, Audi is clearly thinking about proliferating the R8 lineup.
The next R8 to roll down the spotless Neckarsulm, Germany, assembly line may be a lightweight stripper version rather than a more powerful oil-burner. So hints Stafan Reil, the head of development for Quattro, GmbH, which assembles the R8 and almost every Audi that starts with “S” and “RS.”
Lighter, more intensified cars make sense for Audi’s sport cars, Reil tells Car and Driver, much like Lamborghini’s success with the lightened Gallardo Superleggera.
“This is a direction you can go and make business,” Reil says, stressing that Audi won’t build anything that won’t make the company money. “It makes sense for the TT, and maybe in the future in an R8.”
This philosophy would translate well to the R8. Horsepower would rise from 420 to somewhere around 500, we think, with racing seats, fewer speakers, and more carbon fiber throughout the body and chassis. We also expect to see carbon-ceramic brakes and slightly racier bodywork/paintwork. Such a car might be able to hit 60 mph in about 3.5 seconds, given that the “base” R8 does the dash in four flat.
Audi maintains performance while increasing efficiency by 20%.
Those who assumed the 2010 Audi S4 would share its powertrain with the S5 were incorrect. Instead, look for an all-new forced-induction 3.0-liter V-6 that will generate something close to the 340 horsepower found in the outgoing S4’s 4.2-liter V-8.
Why is the Audi S4 moving from a V-8 to a V-6, just as the BMW M3 moved from an inline-six to a V-8? In two words: Fuel economy. Audi’s strategy is to deliver comparable or improved overall performance by toeing the line on weight and maintaining power output by using forced induction on a smaller displacement engine. Doing so will boost a manual transmission S4’s fuel economy on the European cycle to 23.3 mpg compared with only 19.4 mpg for the V-8 S5. That’s an efficiency gain of 20%.
A less powerful, 290-hp, 310 lb-ft version of the engine will be the base offering in the A6 Quattro, replacing the 3.2-liter V-6. Known as TFSI, which in the past has been Audi’s internal moniker for four-cylinder turbos, the new engine may be referred to as the 3.0T in the model name, possibly indicating a twin-charged system using both a supercharger and a turbocharger. While Volkswagen has a “twincharger,” Audi has not yet offered such a system. At the very least, we expect the new V-6 to be supercharged, although what will allow the S4’s version to generate 50 or so more horsepower is still a mystery.
We expect to see Audi roll out its Magna-sourced “sport differential” (BMW uses ZF) in the S5 and Q5 as well, to combat understeer in its four-wheel-drive vehicles. This trick differential, like the one in the BMW X6, adds about 40 pounds. The S4 will be the first Audi vehicle in the U.S. with a longitudinal engine layout to offer a dual-clutch transmission. Now known as S tronic (although even Audi people still call it DSG, as it was originally known, and as VW still calls it), this seven-speed sequential-manual will further improve performance and efficiency.
The supercharger will make the V-6 weigh about the same as the V-8 overall. Add in the requisite safety and luxury features that every new model gets, and it’s a wash. Expect Audi to claim a nominal weight reduction of only 20–100 pounds for the new model, putting it at about 3900 pounds.
Audi will debut the 2010 S4 this fall sometime after the 2008 Paris show in October—making the L.A. show in November a possibility. Expect the new S4 to compete with the BMW 335i for efficiency but the Audi probably won’t have the edge in performance and will cost significantly more. Watch for more details on the new S4’s engine in the coming days.
