Currently reading: GM’s powertrain of the future: E-Flex
Battery-powered family of cars will give GM the lead in sustainability

General Motors, parent company to car brands Vauxhall, Opel, Holden, Chevrolet, Saab, Buick, Cadillac, Pontiac, Hummer and others, is about to take the lead in the race to make the car a sustainable means of personal transportation. Within the next three years, it plans to bring a family of cars it calls E-Flex to market that could make both conventional internal combustion engines and hybrid-electric technology seem harmful and outmoded.

From also-ran to the head of the green field

GM, until very recently the world’s largest car-maker, gave up ground to rivals Toyota and Honda in the late ‘90s and the early ‘00s in the rush to adopt hybrid petrol-electric technology as the saviour of the climate. “The General” was always sceptical about hybrid technology, maintaining that it was expensive and relatively ineffective when it came to cutting emissions, and that other routes around the problem – via biofuels, hydrogen fuel cells and pure electrical power – would prove better.GM’s philosophy will soon be vindicated. Behind the scenes for the last two years, it has been focussing on what it calls “the electrification of the motor car.” That focus is about to pay off with a family of electrically powered battery cars capable of travelling commuter distances without any emissions at all, and of tackling longer trips on a choice of petrol, diesel, hydrogen, bioethanol or biodiesel.

Chevrolet Volt: an early warning shot

Back at the Detroit motor show in January 2007, the Chevrolet Volt concept arrived as the first sign that something big was about to happen at GM. Here was an electrically powered sports car capable of hitting 60mph in less than 9.0sec that could also be charged from the mains and convey you the 40 miles to work and back on electric power alone. Beyond that range, it relied upon a modest, low-emissions 1.0-litre petrol engine that extended its range up to 600 miles. But fundamentally, it was not a hybrid, said GM; it was a pure EV (electric vehicle) backed up by a petrol engine.

E-Flex: don’t call me “hybrid”

The genius behind the Volt is GM’s E-Flex system; it’s the reason why the firm has reallocated some 500 powertrain engineers over the last eighteen months, and it’s been the recipient of more development miles and money than you could realistically account for. Instead of a petrol or diesel engine, E-Flex has, at its heart, a 161bhp electric motor and a 150kg, 16 kilowatt-hour lithium-ion battery. You charge this battery from the mains, or by regenerative braking, and once it’s totally spent, it will have taken you around 40 miles. GM says, in 95 per cent of journeys you will have, by then, arrived at work, or at home, or somewhere else where you will be able to find an electrical power point, and the necessary 3.5-hours it takes to recharge your car. And that alone is worth a considerable slap on the back. Until recently, the battery technology required to give that kind of range, performance and charging time just didn’t exist. It’s only thanks to development contracts GM agreed with electrical giants LG Chem and Continental Automotive Systems that it does now. At least it does in unproven form.What happens once the batteries have run out is just as interesting. GM is developing three different versions of the E-Flex car, each with a different crutch for its electrical propulsion system (see gallery). The Volt used a turbocharged, 1.0-litre petrol engine capable or running on normal petrol, E85 bioethanol or even E100 pure ethanol. However, there is also an E-Flex chassis in the works with a hydrogen fuel cell, and one we’re about to be shown, which uses GM’s 1.3-litre turbodiesel engine. In every case, the combustion engine or fuel cell serves only as a power generator; they’re not attached to the wheels at all. However, they’ll allow GM’s new breed of EVs to go beyond commuter range; to forge up and down the interstates, autobahns and motorways of the wider world. And that, together with GM’s experimental battery technology, should make them as acceptable to the masses as piston-engined cars ever were.

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Son of Volt: the Opel E-Flex concept

Visitors to the Frankfurt motor show this September will be shown the next step on the road to making E-Flex a production reality, a new monocab concept called the Opel E-Flex. Picture it as a more modern-looking, slightly smaller, battery-powered Vauxhall Zafira and you won’t be far wide of the mark. We’ve been given only a couple of enigmatic renderings of the car up to now (see gallery). What’s significant is that this will be the next interpretation of the E-Flex philosophy; the next illustration of what will be possible if the line GM is currently following runs to its completion. And it’s an Opel, which means it could come to the UK as a Vauxhall, offering realistic, practical and affordable carbon-neutral motoring to Brits for the first time.Questions like “when will it be available,” and “how much will it cost,” will have to wait until later. All that GM will say now is that real-world proving tests on the E-Flex battery technology begins early next year. If they go well, the first E-Flex models could be on the road by 2010. There’s no guarantee a Vauxhall or Chevrolet will be among them, of course, but it’s a strong possibility. And before you right E-Flex off as more far-flung wishful thinking from a car-maker keen to win PR points, bear this in mind. The E-Flex mules that begin hot- and cold-weather testing next year are based on GM’s new global compact car platform architecture known internally as the ‘Delta Platform’. So, incidentally, will the next Vauxhall Astra and Zafira, not to mention the eventual replacement for the Chevrolet Lacetti.Coincidence? Don’t you believe it.

Matt Saunders

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