BMW M340D xDrive

This new BMW M340d might be a curious collector’s item in decades to come. One of the last hurrahs for a meaty diesel engine in a sensible car, before the idea gets swept away in the electrification tsunami. 

You’d have to know your stuff to end up buying one of these. Hilariously, BMW will sell you a cheaper, less powerful 3 Series powered by a diesel straight-six: the 330d. It’s got 261bhp, 428lb ft and hauls to 62mph in 5.5 seconds. You don’t really need a faster junior exec than that, do you?

And yet, here it is. The M340d. The twin-stage turbocharged engine has been breathed on, and joined forces with a 48-volt starter-generator motor that adds 11bhp on its own and fills in any pesky turbo lag. 

The result is 335bhp, and a staggering 700 Newton metres of torque. That’s 516lb ft in old money. Small wonder BMW has had to entrust drive to all four wheels, via a fettled eight-speed automatic gearbox. There’s even launch control, for heaven’s sake. 

I’ll say. Getting from 0-62mph in 4.8 seconds in any family estate car is impressive. The way the M340d manages it is just silly though. It’s so fuss-free, you arrive at 62mph and it’s anti-climactic, as if the car’s just getting into its stride. 

Underneath, this is a fantastically complicated machine. The engine is busy maintaining maximum boost pressure wherever you’ve got the throttle, it’s harvesting electrical energy and juggling the electro-surge, and the exhaust gases are on a magical mystery tour through a sewage treatment works-meets-waterslide, so this rampant runaway diesel locomotive actually complies with tougher tailpipe tests not actually coming into action until next year. And yet it’ll still keep a Cayman honest.

And yet, from inside, you’re blissfully unaware of all of this. You just aim and fire. There are modes available, but you needn’t bother toggling them. Jump on the gas, the gearbox readies itself for the onslaught, and you’re off. An M3 pilot would still be busy selecting his gearshift ferocity menu. The M340d is two, no, make that three counties away.

Nope, it handles. As with all M Sport 3s, the ride’s rather taut and busy on back roads, even with the optional adaptive suspension locked into Comfort mode. It’s beautifully controlled though. You could load up the family and set off for holidays without having to swerve around potholes or adopt the brace position for drain covers.

If you’re really cracking on, then you’ll run into the limits of front-end grip sooner than you would in a four-cylinder 3 Series – this is a hefty lump of engine dangling over the front wheels, after all. But that sort of behaviour isn’t what the M340d is about. 

This is a distance-crushing, journey-shrinking monster that uses its monumental muscle, not dainty cornering, to get you home considerably faster than you were expecting.