Opel Ampera: the full, official technical story

Published: 25 March 2009

Opel/Vauxhall predict that the new Ampera production car will sell more in Britain than anywhere else in Europe. The extended range electric vehicle, unveiled at the recent 2009 Geneva motor show, will go on sale here in late 2011 and marketing bosses say the UK is more accepting of hybrids and alternative vehicles than other markets.

It’s not clear at this stage how much the Ampera will cost in the UK, but we’re looking at a likely cost around £20,000. GM hasn’t announced yet where the Ampera will be built, but Britain’s Ellesmere Port is in the frame and the Government is discussing grants to make it possible.

So what’s the new tech on the Opel/Vauxhall Ampera?

A quick recap of the details we already know, and then a few details that we didn’t. The Ampera uses Opel/Vauxhall’s small 74bhp 1.4 gasoline engine mated to a 16kWh lithium ion battery and an electric motor.

Unlike existing hybrid cars, which use petrol engines to drive the wheels when the battery gives up the ghost, the Ampera never uses the internal combustion engine for direct propulsion. Rather, the petrol motor is used purely to generate electricity, which always drives the road wheels.

So the Ampera’s a new sort of hybrid?

Sort of. Studying the electrification of the automobile reveals a murky world of claim and counter claim, but GM says the technology underpinning the US-market Volt and Euro-spec Ampera (they’re the same car, essentially) makes it an extended range electric vehicle.

The basic premise is that 80% of Europeans drive less than 50km a day on average. As the Ampera has a range of 60km on pure electric drive, that means that most journeys could be completed on silent zero-emissions mode. Get home at night, and plug the Ampera into your home 230v socket for a three-hour top-up so you can drive a similar distance tomorrow. Want to drive further? No problem. The petrol engine will kick in to generate electricity for an overall range of around 500km.

And the Ampera removes what Bob Lutz calls ‘range anxiety’ – you’ll never be stranded at the side of the road, because you just pop in some normal 95-grade unleaded (or biofuels, or diesel – depending on the powertrain installed by GM for each market) and off you drive.

>> Click ‘Next’ for more of the new technical details of the Opel/Vauxhall Ampera

So what are the key figures on the Ampera?

The production Ampera will produce ‘less than 40g/km’ of CO2 and consume ‘less than 1.6 litres per 100km’, which equates to 177mpg. Impressive stats. Indeed, a commuter travelling no more than 50km each day may never have to top up their car with fuel ever again, say the engineers. Which sounds great until you consider that the unleaded in the tank will degrade, so they’re planning to set the ECU to wake dormant engines automatically to give them a work-out and pump oil around the engine.

Energy is recaptured during coasting and braking to regenerate battery levels. The engine alone never actually charges the battery. GM points out that charging the car on a typical cheap overnight tariff will cost €0.02 per kilometre travelled, compared with unleaded at around €0.10. ‘Charging a battery through fuel is too expensive and makes no sense,’ says Gherado Corsini, GM’s E-REV implementation director.

Sounds a bit complicated to me!

Yes, the tech is complex. The batteries pack more than 200 lithium ion battery cells into four modules shaped like a T. The whole battery pack weighs 180kg and sits where a propshaft would on a rear-drive car and across the space normally occupied by a fuel tank. This is one heavy car, weighing in at around two tonnes…. In an Astra-sized hatchback!

Those complex batteries require careful thermal management and come with their own heating and cooling system to maintain the optimum operating temperature of 10-30C. All fans and ancillaries are electrically operated, leaving the petrol engine unfettered by pumping losses. And this car has a fleet of different radiators and cooling systems: one each for the engine, battery, charging mechanism and cabin.

GM is planning some kind of guarantee for the batteries to convince sceptical buyers worried about the cost of replacing a dud one. Have you seen how much Apple charges for a new iPod battery these days? It’s almost enough to write your MP3 player off.

They have yet to decide whether to sell or lease the batteries, but we understand it will likely offer both options to buyers. The internal targets for durability is for the batteries to last 10 years or 240,000km, although the customer warranty might not last that long.

>> Click ‘Next’ to read more about the family of extended range electric vehicles

Will there be other E-REV models from Opel/Vauxhall?

There are plans for more models using the Voltec system on both sides of the Atlantic; the Cadillac Converj concept car at Detroit proves that even GM’s premium cars are likely to get the new tech. Of course, these are conditional upon GM surviving its current financial woes, but we’re likely to see a whole family of extended-range hybrids assuming The General does continue trading.

One problem on the Ampera is that the bulky T-shaped battery pack restricts it to being a four-seater. However, it does come with a conventionally sized boot and the battery boffins we spoke to suggested that true five-seaters or even MPVs are possible. Remember, the Ampera uses many of the Delta component sets from the next-gen Astra/Zafira, including the steering and suspension systems.

Will the Ampera drive like a normal car?

We don’t know yet, although prototype drives are scheduled for later in 2009, once the first 80 prototypes have been built.

But the Ampera has some impressive figures on paper. Top speed is limited to 100mph (to improve battery performance) and 0-62mph takes around nine seconds. GM claims equiavalent ratings of 273lb ft of torque and 149bhp – enough to give it the spritely performance of a 250bhp V6, they say.

There’s no gearbox; the electric motor simply changes direction to select reverse gear.

>> Would you ever buy an Ampera over and above a conventional petrol- or diesel-powered car? Click 'Add your comment' below and have your say.

By Tim Pollard

Editorial director of CAR's digital publishing arm. Motoring news magnet

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