What is it?
After a positive introduction to Peugeot’s new large saloon/estate in range topping GT specification two weeks ago, here we’re moving to the opposite end of the price list. The e-HDI, both the cheapest diesel 508 (there is a petrol model that costs less) and the most efficient. The SW estate version tested here emitting Co2 110g/km, the saloon 109g/km.
The e-HDi tag comprises a 110bhp 1.6-litre four-cylinder diesel, stop-start technology and a six-speed electrically controlled manual gearbox (EGC).
What’s it like?
We tested the e-HDi mostly in town, where the engine’s 199lbft of torque proved adequate for reasonably progress in what is a large car, and without becoming overly vocal. However what we weren’t able to verify on this initial test, was the engine’s ability at higher speeds and carrying heavier loads. We’ll conduct just such a test when we get the car back in the UK.
The urban driving did give plenty of opportunity to evaluate Peugeot’s stop-start system though, which uses a reversible alternator rather than a conventional starter motor. Although the engine doesn’t cut out and restart imperceptibly, the refinement is as good as any rival system. It also stops the engine just before the car comes to a rest, rather than waiting until it has completely stopped – without any affect on brake progression. And although the engine is not restarted until you release the brake pedal, it is not caught out with a quick application of the throttle, unlike some other automatic stop-start systems.
Unfortunately though, once on the move, progress gets markedly less smooth. The electrically controlled gearbox feels like very old technology in the face of twin-clutch systems, or even the latest torque converters. In drive the gearchanges are both ponderous and all too noticeable, in Sport the shifts are quicker but still nowhere near smooth enough for a car with otherwise impressive levels of refinement and comfort. Peugeot advise that it is best driven as a manual, which does help, but only by virtue that you anticipate each change, but to my mind this somewhat defeats the purpose of an automatic.
In theory this engine can be made to work with a manual gearbox – but the ECG is required to achieve the Co2 figures – and therefore is not offered. While 110g/km is impressively low for a large car (matching VW’s forthcoming Passat Bluemotion), it hasn’t been achieved without sacrifice.
Which is a shame because in other respects the 508 SW makes a fine estate car, its load bay as large as the Passat’s, if not the Mondeo’s. And compared to the saloon there is little trade-off in driving dynamics for the like-for-like 20kg weight gain and higher centre or gravity.
The e-HDI also our first chance to try a 508 with the standard MacPherson front suspension, and although, again, our urban test route was not the ideal environment to test outright grip, it did prove that the 508 still steers and rides well, if not quite with the same precision as the GT.