Peugeot 308 R Hybrid first drive

The Peugeot 308 R Hybrid could be the next watershed moment for plug-in hybrid powertrain technology, which is flooding into the performance car market in the way that all advanced technologies tend to: from the top downwards.

It has transformed the modern hypercar into something we wouldn’t have recognised 20 years ago, and has left a big impression on the sports car scene in the outlandish shape on the BMW i8.

While the decidedly lukewarm Volkswagen Golf GTE has already given it an outing of sorts among hot hatchbacks, that debut is nothing like what rival European car-maker Peugeot is currently planning: a five-hundred horsepower four-wheel-drive mega-hatch capable of accelerative potency and responsiveness unmatched within its class.

Though the R Hybrid draws primary motive power from Peugeot Sport’s 266bhp 1.6-litre turbo four as seen in the 308 GTi and RCZ-R, it also carries 200kg of not-entirely-useless ballast accounted for by a 113bhp, 148lb ft electric motor for each axle and a 3kWh lithium-ion battery where the fuel tank would otherwise be.

Unlike in other performance hybrids, the 308’s front electric motor drives straight into the Torsen limited-slip front differential, bypassing Peugeot’s six-speed automated manual gearbox entirely. Both front and rear electric motors transfer their power via single-speed reduction gearing.

Meanwhile, the 308 GTi’s suspension has had the kind of fettling you’d expect in order to cope with all that grunt. So the R Hybrid’s axle tracks are 80mm wider than the GTi’s; its front suspension has been entirely redesigned, with new struts, mounting points and wheel angles employed; its springs, dampers and anti-roll bars have all been beefed up; and it runs on wider, 19in forged alloy wheels and Michelin Pilot Sport Cup 2 tyres.

Interestingly, Peugeot’s torsion beam rear suspension survives the transition, with Peugeot Sport’s engineers claiming that it has the rigidity and sophistication to cope with the longitudinal as well as the lateral forces in its new job description.

Much as it’s an abject professional failure for an Autocar road tester, I have to admit that I can’t tell you what 500-horsepower feels like in a car the size of a fairly ordinary family hatchback.

That's because the 308 R Hybrid actually only develops that much urge in launch control mode, and launch control was off the menu during our regrettably brief test drive of this prototype offering.

In the car’s other driving modes - ‘ZEV’ electric-only running, ‘Hybrid’ and Hybrid Sports’ – it delivers a peak of around 400bhp and just over 400lb ft: outputs that the high-voltage electrical system can sustain for flat-out bursts of about five laps on circuit, or more unconditionally during less demanding road driving.

Ask for more than 400bhp from the car for much more than the length of a couple of typical straights, the engineers say, and you soon have a very hot, very depleted lithium-ion battery to nurse back into condition.

But even with a piffling 400bhp to struggle along with, it feels like an indecently rapid thing. Flat-out, just about fast enough to outsprint its rivals from Quattro GmbH and Mercedes-AMG up to about 100mph - after which point those electric motors really do become ballast, the ECU ramping down their output levels in order to give the battery an easier life.