Ancient History

SnoMo1 at aol.com SnoMo1 at aol.com
Wed Sep 4 15:53:24 GMT 1996


Gentlemen,
I have been on this list for some time now, and have found your discussions
informative, and interesting. This latest thread (discussions of gas milage
from a big block) has finally prompted me to ask a question. 
Why is it  a 3500 lb big block car can get 12mpg when on the other end of the
weight (and size) spectrum, my parents have a 14,000 +lb motorhome powered by
a 454 chevy (tbi), with ovedrive, 5.13 ? gears, 20" wheels (rim dia) , and
the areodynamics of a house, and still get 10-11mpg on the highway. And, when
pulling a towed 3700lb 
vehicle (Brono II 4x4) they still get 8-10mpg. This has been documented over
10's of thousands of miles. 
And yet, if I buy a full size truck with 4-wheel drive and a 5.0 to 5.8 litre
V-8, I can only excpect 16mpg? Do you think that possibly many vehicles are
being over-geared? I recently changed the gears on my 2.8 L ford ranger from
3.73 to 4.11 and actually saw a slight increase in mileage. I think this was
cause by always having the foot to the floor. Now, the engine revs higher,
but I notice the pedal isn't constantly kissing the carpet. And, by the way I
did take into account the odometer error after changing the gears (plural,
4-wheel drive makes changing gears a pain!).


Just thinking outloud again,

Mark



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