BMW three-cylinder 2013: First Drive

BMW took enormous pains to tell motoring.com.au - four times in 15 minutes - that the 1 Series we were about to drive was neither a production car, nor will it ever be a production car.

It was, they said, a pure prototype - one of three built to show the bona fides of the new three-pot as it sits now.

It was so not-for-production that not even the engine’s output level is a production number. Instead, BMW said it cranking out 130kW at 6000rpm and 270Nm of torque … somewhere in the rev range.

I figured I’d trick them by making my first move a practical one, by opening the bonnet. BMW was, disappointingly, willing to show me only a thick-set but extremely short engine lurking well behind the front axle line in the current 1 Series engine bay.

In fact, there was about a foot of empty crash space directly in front of the B38 engine – enough, quite clearly, for another B38 to sit right in front of it (which, in six-cylinder guise, it effectively does).

Its only distinguishing prototype feature inside was a bright red “kill” switch drilled through one of the cup-holders, but the eight-speed auto’s shifter was the standard unit. Otherwise, it was a standard five-door 1 Series.

But when I fired it up the little motor suddenly could. It burst into an idle that was oddly charming but utterly devoid of tremors.

It idled at around 800rpm and it did it with a level of noise very little different to the N20 four-cylinder engine it’s hell bent on replacing.

BMW’s new triple will, initially, only come mated to this eight-speed automatic and that helps it move off calmly. There’s no launch control system, funnily enough, but the rear-drive 1 Series can be convinced to chirp the rear rubber, such is the little motor’s torque.

BMW insists the three-pot is more six-cylinder than four-cylinder in its character and it’s absolutely right.

It delivers a deeper engine note than the four-pot in the first half of its rev range and doesn’t really behave much differently anywhere at part throttle, either.

From about 4000rpm, though, it starts to act differently. Swing the attitude across into a more traditional, BMW style of attack driving and the B38 swings right across with you.

Its aural character changes note quickly and cheerfully above 4000rpm. Where the four-cylinder needs to build into each new characteristic sound, the B38 flits there with the same ease and conviction as the classic BMW six-cylinder family.

It’s the same in throttle response, because it’s a little soft at lower revs, though it will happily pull eighth gear without complaint from as little as 1500rpm. This combination happily pulled top gear at low speeds, cruising with 1800rpm on board at 100km/h.

Let it swing above 3500rpm, though, and the engine displays a cheerful alacrity in delivering your changes in foot angle through to the rear tyres.

Its throttle response is actually one of its highlights and it lets you float the 1 Series (what would you call it, a 115i?) through sweepers on its limit of adhesion with the steering wheel locked in one place, doing all of your adjustments via delicate fiddles on the throttle.

And all the while the deep, rich wail of the engine actually charms you with its reactions, its timbre and its ability to show a depth of character lacking in the four-cylinder.

It does all this without any disturbing lurches through torque transfer on sudden throttle shut-offs or any moment of inertia changes, either.

It spins out to 6500rpm (though the tacho showed 6600rpm) and BMW’s engineers have given it a sharp, Golf GTI-ish braaap with each gearshift when it’s in its manual mode. In the standard Drive mode, though, it slips the shifts through silkily.

There’s another bonus, too. The entire engine sits well behind the front axle line and while it might not punch as hard as some in the current engine range, its lighter weight takes the agility levels of the 1 Series hatch to a whole new level.

Here for more specs and details on the first BMW three-cylinder

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