Another week, another new BMW diesel. And like the 535d we drove last week, which is powered by a twin-turbo 3.0 rather than a 3.5-litre six, this one has a misleading badge.
Because the 318d has in fact a 2.0-litre engine. Look under the bonnet and you’ll find not a 1.8, but a detuned version of the same 1995cc turbodiesel you’ll find nestling in the 320d – which is a firm favourite here at Autocar.
Last year the 320d replaced the 318i as BMW’s best-selling model, and the 318d is an opportunity for the boys from Munich to cash in on the current craze for oil-burning executives. At £22,650, our SE version weighs in at £1125 less than a 320d SE, with power down 35bhp to 115bhp and torque down 36lb ft to 207lb ft.
If you were expecting any big cuts in running costs, forget it. Stick with the standard manual gearbox and the Euro4-compliant diesel’s CO2 emissions are down 2g/km to 151g/km, but it’s in the same 16 per cent company car tax bracket, and you will get just 0.9 miles extra from every gallon of the black stuff, according to BMW’s claims.
You won’t find the engine lacking for power or refinement; if anything the lower-tune motor has a smoother, less gruff engine note than its gruntier brother.
It’ll still get to 62mph from rest in a respectable 10.6sec, just 1.8sec behind the 320d and only bettered among the BMW’s premium rivals by Jaguar’s X-type 2.0d. Only when trying to make really swift progress will you miss the 320’s extra poke, in particular the thump in the back that comes when its extra 36lb ft is delivered at 2000rpm.
More importantly, the 318d retains all of the qualities that make the 3-series one of the UK’s top-selling cars: neutral handling, superb build, peerless driver environment and – despite the optional 17in alloy rims fitted to our test car – a firm yet compliant ride.
To cut costs there’s a five-speed box in place of the 320d six cogs, but it’s no bad thing because the well-spaced ratios are swapped by a delightfully positive and fluid change. The solitary gripe that still bothers us about the all-round driving experience is the steering, which seems overly weighty and imprecise around the straight-ahead.