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Bodystyle, dimensions and technical details

The multi-motor hybrid powertrain of the 508 PSE is similar to the one used by that experimental 308 of a few years ago; but the ways in which it is different reveal a lot about the limitations of using electric motors, batteries and combustion engines in performance cars, and the challenges as regards robustness of power generation, and management of both weight and heat, that will exist for all car makers that attempt the same switch Peugeot is now making.

Just like the 308 Hybrid R, this 508 uses a front-mounted 1.6-litre turbocharged four-cylinder petrol engine as its primary source of power and also has an electric drive motor for each axle. The front motor is sandwiched between the petrol engine and an eight-speed automatic gearbox, and the rear one drives the rear wheels via reduction gearing.

From the beltline up, the PSE goes for menace rather than flamboyance. The integrated wing is relatively subtle, and the rear glasshouse is heavily tinted, whether you want it to be or not.

The electric motors could make as much as 110bhp each, which is roughly as they did on the Hybrid R, but the 508 PSE’s combustion engine is rated to produce only 197bhp, down from 266bhp in the 308 Hybrid R.

That change may allow the motor some margin to work as a current generator without affecting how much power it can supply to the front wheels but it is just as likely to be about preventing it from producing so much heat that the electric half of the car’s propulsion system becomes adversely affected.

Peak ‘system output’ for the 508 PSE is 355bhp, rather than the 400- odd you might have just tallied up, and peak torque is a combined 384lb ft on tap from just 500rpm.

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The former is because the car’s lithium ion drive battery (11.5kWh, capable of facilitating a WLTP lab test 26-mile electric range) can only output enough current for the motors to draw up to 158bhp between them at any one time – and that’s only when the car is operating in Sport mode. It’s some improvement on the robustness of performance of the 308 Hybrid R – whose drive battery had only 3kWh of capacity, was depleted very quickly and was part of a car with some clear heat management issues – but it also only leaves this car in a broadly competitive place on power-to-weight ratio versus its nearest rivals, not the outstanding one that some might expect of it.

Peugeot Sport has done its familiar thorough job on the 508’s suspension, widening both axle tracks, reappraising its springs, dampers and anti-roll bars at all corners, fitting new adaptive dampers and new Alcon front brakes, recalibrating its electromechanical power steering and fitting 20in alloy wheels and Michelin Pilot Sport 4S performance tyres.

The car can be had in saloon and SW estate bodystyles. We tested the SW, which came with a hefty but not discouraging kerb weight claim of 1875kg. (A BMW M340i xDrive Touring, which has little or no hybrid-related ballast, is only 130kg lighter.) Our test car weighed 1892kg on the scales with a full tank of fuel.