Thursday 28th June 2012

PH Blog: BMW M6 and the art of noise

A roofless M6 ... all the better to enjoy some epic V8 noise, right? Wrong.

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It says something about the state of the world when the PistonHeads review of the latest BMW M car concludes ... you'd be better off buying the diesel version. It says even more when the majority of replies in the comments thread seem to agree too!

BMW prefers the sound to come from the speakers

And I can't help but think one of the key contributors to this is that the M6 just doesn't sound good. Or rather, anything like you'd hope a 560hp, V8-powered mega-coupe should. I've wittered about the importance of this before and PH opinion on the fact BMW has resorted to digitally enhancing the noise on both the M5 and M6 has been pretty unequivocal. The outcry has been immense but you know the worst thing? Even with this trickery it still fails to excite.

I spent most of my time on the M6 launch in the coupe, figuring this was the more manly and PH of the two. But, diligent as ever, I did take the Convertible out too and, in fairness, it's a pretty impressive piece of kit with none of the wobble you might expect of a roofless four-seater. As you might hope, given that the reinforcement required tips it over the two-tonne barrier.

We'll talk about that another time but at least, I thought, without a roof I'll be able to get an honest impression of what that undeniably mighty M twin-turbo V8 really sounds like, rather than rely on some synthesised version playing through the speakers.

The best way to enjoy a BMW M V8? Actually no.

Trouble is, the answer is rubbish.

And that's a real problem. If you're paying a £30K premium over the 640d - a car that'll do 0-62mph in 5.3 seconds but also achieve 50mpg - you at least want it to sound like an M car. Instead the M6, bar the odd little upshift parp, sounds like an overboosted, downsized four-cylinder. I knew the answer but I even had to check with the engineers - was it a flat-plane crank? Nope. The guys at AMG must be feeling particularly smug too, having managed to make their equivalent 5.5-litre twin-turbo V8 sound nearly as epic as the normally aspirated 6.2 it's steadily replacing.

It's an issue affecting BMWs of all shapes and sizes - the diesels sound and behave more like petrols while the petrols do the opposite. Fine, the M6 delivers its peak torque at 1,500rpm. But so does the 640d, and with 465lb ft it's only 35lb ft down and, coupe for coupe, weighs 135kg less!

Looks mean, goes like stink ... sounds dull

An M engine should be all about drama and emotion, not diesel-like power delivery. But this twin-turbo V8 leaves the hairs on your neck very much unpricked. Sure, the M6's V8 can and will rev out to over 7,000rpm and the engineers are very proud of its ability to do so, referring constantly to its 'high-revving character.' But where's the incentive to do so if it's already delivered its maximum torque and doesn't even sound good with a few more revs on the dial? True, BMW is probably only responding to criticism that the old V10 was too peaky. But it's possibly gone too far the other way.

Dan

[Saxon12]

Lovely colour, I like it very much!