REPORT: BMW M5 dropping V10 for turbo V8
The straight six in the first BMW M5 supersedans was silky smooth and plenty powerful, but it was getting a bit long-in-the-tooth, so it had to go. It was replaced by the 400 hp V8 in the E39, then later with the fire-breathing V10 in the current M5 (above) that pushed horsepower into the stratosphere, particularly when you activated the 'M' button. That engine remains powerful, but with CO2 concerns, fuel economy standards and the fact that the V10 isn't available in much of anything else in BMW's lineup, it seems like the next-gen M5 will probably find its motive power supplied by a V8 instead. If a V8 is good enough for the Audi RS6 and Cadillac CTS-V, perhaps it's good enough for the BMW M5, too.
We saw speculation about a V8 M5 as far back as May, 2008, and more recent speculation that it was going to be a twin-turbo V10 instead, but now Inside Line is reporting that BMW reps have confirmed that a V8 will indeed be in the next M5's engine bay – although they didn't confirm which one. Most likely, it will be the 4.4-liter turbocharged V8 that first appeared in the X5M and X6M. With 555 horsepower and 500 pound-feet of torque, it falls right in the ballpark with other supersedan outputs. That new powerplant will sit in a new cradle as well, with the all-new 5-Series just months away. Around these parts, we're starting to refer to this next generation M5 as the Goldilocks Edition. Six wasn't enough, ten was too much and eight is just right. Thanks for the tip, Derick!
Gallery: Review: BMW M5
[Source: Inside Line]
Reader Comments (Page 1 of 3)
Infidel 11:04AM (9/28/2009)
Thats not totally correct, the previous M5 had a V8 which was a fun car.
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quiteurgent 11:06AM (9/28/2009)
how did you forget about the 5.0L N/A V8 in the E39 M5?
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Craig 11:37AM (9/28/2009)
That's what I was thinking...
cancuno (formerly Mike) 11:51AM (9/28/2009)
yea I was like wtf?
typhoon5000 12:19PM (9/28/2009)
Same here, WTF? I thought the 5.0L V8 was an unforgetable motor it was so good, but I guess not.
zamafir 11:05AM (9/28/2009)
bi turbo v8? sounds fine, sounds like audi will return to the previous RS6 forumula as well.
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Shawn 11:41AM (9/28/2009)
Twin Turbo... Bi-Turbo is a turbo that goes both ways
Affalterbach 1:02PM (9/28/2009)
BiTurbo = parallel turbocharging
Twin Turbo = mostly sequential turbocharging
Or atleast that's how I remember it....
zamafir 1:22PM (9/28/2009)
I just call it like audi does, even the tupercharged.
Infidel 11:06AM (9/28/2009)
Oh, also the M6 packs the V10 apart from the M5
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pirate 11:07AM (9/28/2009)
Hopefully it keeps it too
Jung 11:07AM (9/28/2009)
I guess the global recession continues...
I hope Mercedes doesn't get rid of its V12.
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Dr. Greenthumb 11:17AM (9/28/2009)
Has nothing to do with global recession, has more to do with these engines being unnecessarily large (physically). Difficult to package, DOHC heads already raise the center of gravity in these motors. The eights represents less mass. Less mass contributes to better handling.
hashiryu 11:21AM (9/28/2009)
Add two turbos, inter-cooling and associated plumbing, I'm not so sure that there is much of a weight benefit to be gained.
Joe K. 12:14PM (9/28/2009)
Don't forget the torque!
The current V10 is less powerful than the Turbo V8 and the Torque is much higher. Seems like a win-win to me...
esoterica 12:17PM (9/28/2009)
And V8's are the second-most inherently balanced engine configuration after the inline 6. V10's are ... not. And the BMW V10 sounds awful. Really actually the only V10 I've heard that sounds good is the one in the Gallardo (and I would assume, by extension, the R8 V10) but its shrieking sound wouldn't be very appropriate in a Jekyll/Hyde sports sedan.
Toy Yoda 1:09PM (9/28/2009)
Hey Dr. Greenthumb, well by your reasoning, why not stick an LS7/LS9 motor in there? It has compact packaging, it's lighter, and lower center of gravity. It's even more reliable. Heck, I don't mind it at all, and I own a BMW. The LS7 has comparable numbers to the motor mentioned in this article. In fact, I want to swap the motor in my 6 series with an LS4, LS7 or LS9.
hashiryu 1:30PM (9/28/2009)
@ Estoerica......
and V12's?
Artega 1:54PM (9/28/2009)
I liked the V10 in the M5. In my opinion, it sounds really good.
MikeW 2:53PM (9/28/2009)
A cross plane crank V8 is not inherently balanced.
V12 is the best. There really isn't any synergy with a V16 configuration, and the marginally smoother power delivery is enough to offset reduced power (for same displacement)
V10 are variable: A 90 degree odd firing version can utilize the same balancing arrangement that V8's use.
http://www.timberwoof.com/motorcycle/V-TWIN-7.html
Motorcycle V4 are usually 180 degree crank to have the slight imbalance offset each other.
The result is an acceptable, because engine is very narrow, side to side moment imbalance. Though Honda does 360 degree crank with balance shafts in the ST1300 (for exhaust scavenging, think of it as two inline2 engines)
an inline8 has about the same balance as a x-plane V8, but makes crap for power-due to manifolding
a boxing 8 is as balanced as a balanced cross plane V8 (and still fires LRLLRLRR)
a flat plane crank V8 with balance shafts is almost as well balanced as a balanced x-plane V8
Inline 6 > boxing 6 > Vee 6