The Opel Ampera is the identical sister car to the Chevy Volt only sporting Opel design cues. It will be built side-by-side with the Volt in Michigan for export to Europe where it will go on sale in 2011.
Like the Volt, only a little later, Opel is beginning to allow journalists to test drive an Ampera. Famed British publication Telegraph had its chance at the wheel and author Andrew English has produced an interesting review. GM has been careful to only allow journalists, myself included, the chance to test drive Volts at modest sub-50 mph speeds, limited to pylon-flanked parking lot impromptu tracks. English had the chance to take an Ampera out on the highway.
He was pleased with the spacious and attractive interior calling it “comfortable, classy and commodious.”
He found acceleration strong noting the car “charges hard” up to 50 mph. After that he perceived, “the single-speed electric motor’s flat torque curve has begun a nose dive and acceleration at high speeds is poor.” Perhaps this is why GM hasn’t allowed US drives beyond 50 MPH. That was the fastest speed I could hit on a roughly half mile track, though one US reporter was said to take a Volt to 92 MPH at the Warren Tech Center, on a side road.
English suspects the perceived power fade at high speed is because the Volt/Ampera’s top speed is100 mph which is lower than most similar-sized gas sedans which is typically 130 mph.
He claims GM has a solution forthcoming:
General Motors is working on the problem and this autumn plans to unveil a mechanical direct-drive from the engine to the front wheels through the existing twin-clutch planetary gearbox. This would reduce the energy losses of turning petrol power into electricity to drive the car at high speeds, and would also give the Ampera more spritely overtaking performance.
This claim, if true, is rather shocking because it flies in the face of everything GM has said in the past and would mean the gas engine could power on even during the first 40 miles.
I reached out to Volt spokesperson Rob Peterson who with utmost respect for the reporter denies this is the case. He also notes the Ampera English drove is a 65% calibration build, whereas current Volt test cars are at a much more refined 99%. This is what Peterson had to say about the powertrain change claim:
This report is inaccurate. First off, the Volt cannot be driven without electric power. It always makes use of electric power within the drive unit.
Secondly, we have no plans to make any mechanical or control strategy changes prior to launch.
The team is in the final stages of validation and durability and have not identified any reason to make any changes. We have a very innovative drive unit that includes a number of clutches and a planetary gear-set which is highly efficient and exists in our pre-production vehicles today. For competitive reasons we won’t provide more details on the operation at this point, but will soon.
Source (Telegraph)


