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Old 04-07-2009, 02:16 AM   #30 (permalink)
Sean T.
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Join Date: Apr 2008
Location: Lake Orion, MI
Posts: 448

Taurusaurus Rex - '97 Ford Taurus GL (Sedan)
90 day: 19.39 mpg (US)

Blue Wagon - '00 Ford Taurus Wagon SE Comfort
90 day: 19.61 mpg (US)
Thanks: 6
Thanked 18 Times in 11 Posts
Quote:
Originally Posted by MechEngVT View Post
I have read that BMW instructs drivers to accelerate at 75% engine load and shift when the engine's mean piston speed reaches 1200-1500 feet per minute. Mean piston speed is a function of engine stroke and RPM.

Vp=RPM*S/6

Vp= mean piston speed
RPM= engine speed
S= engine stroke length, inches

This keeps you in closed-loop operation (for EFI) at high volumetric efficiency with low frictional horsepower loss for as short a time as possible before you can achieve steady-state cruise and/or EOC. It is what I like to say is accelerating "smartly."
Using this formula, and my engine stroke length of 3.1", I came up with an ideal range of 2322-2903 RPM... is is really possible that it's that high?

It would explain my dramatically low mileage compared to my fellow Taurus drivers. I try to always keep the engine under 2000. Never over 2500.
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