Based on the 2.0-litre diesel 320d, the D3 is faster and keener than the regular car. So although the four-cylinder turbocharged engine remains unchanged internally, it gets new ancillaries: bigger injectors, a different turbo (part 330d, part Alpina), the 330d’s intercooler and exhaust and a revised ECU. The upshot is 197bhp - up 34bhp over the 320d - and 302lb ft, up 52lb ft.
What's it like?
It’s not all good news, though. There’s more turbo lag and throttle response isn’t as sharp at low revs, but acceleration is strong once the turbo has spooled up.
Otherwise the Alpina is a convincing driver’s car. The ride is firm but just short of harsh – it rides on 19in wheels shod with 35-profile front and 30-profile rear tyres – while the steering is accurate and responsive.
Throw the D3 fast into a corner and it will initially understeer gently as you nudge up to its limits, but it can be coaxed into mild oversteer if you give the steering a flick and add plenty of throttle. With no limited-slip differential, tail-out antics are limited, although it corners in a satisfyingly flat and adjustable manner. Grip levels are also high.
Should I buy one?
So it’s an entertaining driver’s car. But despite the extra power, the Alpina isn’t good enough to start bridging the gap to the very talented six-cylinder 330d. Which is why it’s not priced to do so. At £26,995, the D3 even undercuts the top-spec 320d M Sport by a whisker.