Mercedes E300 Hybrid (2013 CAR review)

As six-pot turbodiesels make way for four-cylinders, you’re increasingly unlikely to spy a 3 on the rump of any big German saloon. Hence you’re more likely to see 520d, E250 CDI and A6 2.0 TDI than 530d, E350 CDI and A6 3.0 TDI. But Mercedes is offering a way to get a 3 back on your bootlid while bettering the performance and emissions of those number 2s: it’s the E300 Hybrid, a car that pairs a 2143cc diesel four with a hybrid boost.

What are the Mercedes E300 Hybrid's vital stats?

So while the E250 CDI makes 201bhp, 368lb ft, returns 56.5mpg and emits 130g/km, the hybrid adds an extra 27bhp and 184lb ft – though at different peaks to the diesel’s, so don’t simply add the two together – plus returns 67mpg and emits 109g/km.

It’s have your cake and eat it stuff: the hybrid bit often works at low speed – so long as you get all bomb-disposal squad on the throttle – meaning silent progress rather than the harsh rattle of a four-pot TD; meanwhile, the lithium-ion boost means you’ll struggle to spot the reduced cylinder count when you go for a fast overtake. What’s more, the electric motor is packaged along with the auto ’box, and the batteries are packaged so as not to take up any boot space – though there is a 110kg penalty.

How does the E300 Hybrid drive?

It’s a very cleverly integrated system, with the transition between the two power sources being subtler than you might expect, especially given we’re working with the switch between silence and diesel here, where most hybrids slip between silence and petrol.

The tech gets to strut its stuff more often than you might expect too: back gently off the throttle at most speeds and the rpms fall to zero. Because of that, and because the E300 has ample performance, you don’t work it as hard as most four-cylinder TDs, which means that refinement is noticeably improved. Press ‘S’ and the hybrid gubbins/coasting mode nods off and the gear-change points become more aggressive, but it feels a perverse exercise.

What sort of economy figures does the Mercedes E300 achieve?

With two kids, two adults and a week’s worth of kit, I covered over 1500 miles in Europe at an average of 52mph and 40.4mpg – not bad considering much of our journey was spent at a 90mph autoroute cruise. Having to refuel only once every 500 miles or so was also a pleasant bonus.

But here’s the but: while the mechanical-spec might position the E300 alongside the E250 CDI, the £39,645 sticker means it’s more accurately an alternative to the £39,250 E350 CDI – 261bhp, 457lb ft, 47.1mpg, 156g/km – a car I’ve previously extracted an easy high-30s mpg from in slightly slower-paced UK motorway driving. It’s hard to see there being more than 5-10mpg between the two in non-urban driving – a worthwhile chunk, but not the 20mpg difference promised on paper.

Verdict

It boils down to this: do the mpg and CO2 savings work for you, perhaps on a company-car level? If they do and you like a comfort-focussed car, you should like the E300 Hybrid. But if you’re buying privately and your annual mileage isn’t too daft, the E350 CDI remains the better all-round E-class.