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Old 08-23-2012, 12:03 AM   #18 (permalink)
rmay635703
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Quote:
Originally Posted by Mustang Dave View Post
My lifetime average is over 47% over EPA combined. What am I doing wrong?
Your driving a manual transmission.

Despite being a physicist the op has little understanding of how our engines behave real world, there are volumes past and present about how inefficient most engines are, how many losses there are in various drivetrains, how most engines run efficiently near only one high level load, etc, etc.

Simply put if you drive a manual transmission you can load up your engine to its most efficient level, which is usually somewhere between 75-90%.
It may be more or depending on auto/manual and whether your car richens up dramatically.

Anyway Your motor inevitably makes power most efficiently near its design limit (least losses VRS power created) so accelerating along that curve is ideal if you can do it and your automatic doesn't twart your efforts.

This means if you pulse at max efficient power and kill the engine you will get the best FE out of your platform.

If you instead drive at low load levels your motors power will be wasted on parasitic losses AKA, throttling losses, compression and other internal engine efficiency losses and more on friction than at a high load level where internal friction is less of a percentage of total engine power.

Cheers
Ryan
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