Richard,
the quick answer, using the assumptions below, is that 5th gear will
always give you better mileage, because the engine is taking fewer
'gulps' of air/fuel mixture per mile of road traveled, therefore
ultimately consuming less fuel in a given amount of time
elapsed/distance traveled - in the case of 60 mph, the engine would be
taking in 1500 'gulps' per minute (3000 rpm / 2) in 5th or 1900 'gulps'
per minute (3800 rpm / 2) in 4th.....this is the simplified version,
ignoring such factors as throttle position required in each gear, head
winds, engine condition, carb. jetting, altitude above sea level in
relation to carb. jetting, etc., etc.
Pete Long
'68 (nee 2L Solex) KA24DE
"Ryan, Richard" wrote:
>
> I have 2 questions for you techie types:
>
> 1. Which gear provides more miles per gallon of fuel, fourth or fifth?
>
> 2. Why?
>
> ASSUMPTIONS
> * Straight and level road
> * Constant 60 miles per hour speed
> * 3000 rpm in fifth
> * 3800 rpm in fourth
>
> Dick Ryan ex. 24022
> (650)312-4022
> Risk Management Dept. #857
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