Rev Matching the BMW: Where's the Off Switch?

Jim Motavalli

Jim Motavalli | Aug 23, 2016

I’m driving the 2016 BMW 340i, and I love it. The three-liter TwinPower turbo six (with 24 variable-control valves) is a treat in this smaller platform. The car ($58,420 as equipped, with $13,000 in extras) has gobs of power, and the handling to keep it on the road. Plus it’s a handsome beast in red.

The six-speed manual shifter in the 340i has hidden tricks. (Jim Motavalli)

Except for one thing. Well, two, but one is minor. Why isn’t it a 330i? I thought I understood BMW nomenclature, but they’ve changed it for reasons only the Germans know. Once a 328i had a 2.8-liter engine, but now the 328 has a two-liter. And the 335i has a three-liter. Apparently, the numbers refer to the amount of power you get at the wheels, not engine displacement. I sort of get it….No, actually I don’t.

The second thing has to do with the six-speed manual transmission. Normally I love manuals in sports sedans—wouldn’t have them any other way. But this one feels weird.

How so? It’s mostly downshifting. I’m used to significant engine braking when making, say, the 5-2 shift. The engine’s RPMs go up wildly, but that’s part of the fun. And it’s useful if you don’t like overheating your brakes. In the 340i, it’s just not there. Instead, the car shifts smoothly and you’re in an already adjusted second gear, without slowing down much.

Now I know racers use a technique called “heel and toeing” downshifting to change gears while simultaneously applying both the brakes (the ball of the right foot) and the throttle (the heel), thus matching engine and wheel speed. It’s all about increasing stability and not losing momentum around a turn where shifting is necessary. The 340i does this so-called “rev matching” automatically for the driver. I see the benefit, but I immediately wanted to turn it off.

The problem is, there’s no simple switch—turning off rev matching means using “Sport+” mode, which also turns off electronic stability control. And that I just don’t want to do—I’m not Stirling Moss.

The 340i is a fine driver's car, with the exception of one tiny quirk. And why isn't it a 330i? (Jim Motavalli)

This automatic rev-matching thing is not solely the province of BMW. The Mini Cooper S uses it, though of course that’s a BMW in all but name. Nissan calls it SynchroRev Match, and claims to have invented it. Porsche likes it, too, as does General Motors for the Camaro, Corvette and Cadillac ATS-V. On the Corvette Stingray, for instance, you flick a steering wheel-mounted switch to turn it off. (The same car has a nasty 1-4 shift that avoids second and third gear to save gas. It can’t be defeated.)

This issue will be foreign to readers who always drive automatics. Why not let the car make shift decisions all the time, say most Americans. Rev matching could be seen as a way to ease manual drivers into an inevitable acceptance of automatics, but more likely it's simpler than that--they had the technology, so why not use it?

This is the point in the column where I admit that rev matching is probably a very good thing, and my reaction to it is somewhat curmudgeonly. I’ll probably get used to it, and won’t be able to imagine it not being there. I got used to all kinds of other things—navigation systems, back-up cameras, heads-up displays, even quirky infotainment systems without volume knobs.

In the meantime, though, while I’m adjusting, I’d prefer to be able to turn rev matching off without penalty. Here's a closer look at rev matching--and why you might want to do it--on video:

And here's how active rev matching works on the new Corvette:

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