Posted by Horisly in
BMW on 01 27th, 2012 |
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Tech Talk: BMW ///M Loses Their Spark Plugs & Blows Our Minds
It’s been a long time coming, but after years of speculation, hope and fear, BMW’s M division has launched their first Diesel cars/SAVs. As if to apologize for the lack of spark plugs, the marketing gurus have branded these new M Diesels as “M Performance Automobiles.” We’re hard at work trying to determine if this is a cypher with encoded meaning. Here’s what we know about the new M diesels so far, and why they may be slightly sub-branded from the M division. A matter of redline. The heart of an M car is always its engine. Historically, M cars have had hearts that beat very fast – as in 8,000 + rpm; in the medical community we’d call that ventricular tachycardia. In the BMW community, we call that spinning to heaven. Predominately due to the specific burn rate of diesel fuel, compression-combustion engines (diesels) cannot rev as high as sparked (gasoline) engines. Most diesel engines in the automotive market today rev to a maximum of 4,000 to 4,500 rpm. Above 3,000 rpm, most of these diesels will sound and feel like they are about to spin themselves to oblivion, becoming rash, noisy and a bit unhappy. BMW diesels, however, welcome revs – whatever their redline might be. In the case of the new M diesels, redline is set to a maximum 5,400 rpm. That may not sound very high in the company of high-revving M engines, but trust us: for a diesel, that is stratospherically high. Consider that modern turbo-gasoline M engines – such as the S63tu engine found in the new F10 M5 – rev to a maximum 7,200 rpm, and this high-revving diesel appears that much more impressive. The new M diesel gives up only 1,800 rpm to the highest revving turbo-gasoline M engine, and produces prodigious power along the way. This diesel, ladies and gentlemen, is an engineering marvel, a technological masterpiece. We will lay down the farm to bet it will win multiple engine of the year awards. This 3.0 liter turbo diesel is a genuine M engine – let’s get that matter out of the way early on in this tech piece. One turbo, two turbo. Two turbo, three? Did somebody say three turbos? Isn’t that kind of a lot of turbos? Indeed it is, and we don’t mind one bit that there are six scrolls packing air into...