On Mon, 25 Aug 2008 13:44:14 -0400, spamTHISbrp@yahoo.com wrote
(in article
<15ff3e92-abd7-4335-a5a7-f1b662416551@79g2000hsk.googlegroups.com>):

> Not surprising as a result, smaller engines are set up to make better
> power in the higher revs, the cylinder filling is just so much better
> at those revs it offsets the pumping/friction losses.

I recall some years ago BMW did some tests with one of their cars and
found that the best gas mileage was achieved by accelerating at wide
open throttle (WOT) to cruise speed, then holding constant speed. That
would apply only to that model of car, whose engine was designed to run
most efficiently at WOT, and similar cars by BMW and others.

> I'd have to guess an engine wears out after part X rubs past part y
> for the umpteen-billionth time and it just wears out.
>
> As long as you're not lugging the engine, having the car travel in the
> highest gear possible will minimize the number of 'rubs' per mile
> driven.

In 1955 I spent six months as a co-op student working at the Ford Motor
Co. proving grounds, then located in Dearborn, Michigan. One of the
things I helped do was to run fuel efficiency tests on Ford and
competitors' cars, all at constant speeds (that is, not from a standing
start like the BMW test above). The highest efficiency was invariably
obtained at the lowest possible speed in the highest possible gear.

Things may have changed in 50 years, but I expect that relationship
still holds.

--
John Varela
Trade NEW lamps for OLD for email.