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Old 10-28-2012, 02:11 PM   #22
John V
No more BMWs
 
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Join Date: Apr 2005
Carmudgeonly Ride: Ram, MS3, CX-5, RX-8
Location: Glenwood, MD
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Quote:
Originally Posted by JST View Post
The 26 mpg thing isn't really fair, though--that's in the Corvette, which is small, light, and (most importantly) has an interplanetary overdrive gear.

Put a 4.x liter DOHC V8 in a similar car with a similar OD and I don't know that the mileage would be any worse.
You get away with a massive overdrive when you have big displacement. BMW can't do that in the m3 because the v8 isn't nearly as torquey.

Engines run most efficiently at low rpm but high load and wide throttle openings. So a BMW 4 liter v8 turning lots of revs at freeway speeds gets worse mileage than a corvette 7 liter turning just above idle.
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