"Larry Bud" > wrote in message
oups.com...
>
> Cory Dunkle wrote:
> > Driving at 85 MPH vs 70 MPH only reduced my mileage by .3 MPG. So
> take that
> > you speed kills freaks and tree huggers. Anyhow...
>
> You need more stats:
>
> -How far did you drive at each speed
~225 miles
> -Did you do them within the same time period (atmospheric conditions,
> temperature, affecting combustion and tire pressure)?
Approximately the same temp, wasn't very windy in either direction,
everything was pretty much the same.
> -On the same stretch of road (hilly?)
Yep, same roads each way, both directions run next to eachother the whole
way.
> -What about wind?
Not much wind going either direction
> -How did you calculate MPG? (Car computers are not THAT accurate IME).
Computers? We're talkin' about a '68 Galaxie here. I filled the tnak and did
the math... No topping it off or anything either way.
> -Same type of gas?
Ran 93 octane both directions. Bought Sunoco in NJ and Shell in CT. Both are
good quality gas so I doubt there is much difference in fuel quality.
> -Same vehicle weight?
I had a few extra things on the way back, not more than a 20-25 lb increase
though.

Even if you figgure a couple tenths of a MPG error from various things, such
as perhaps the pumps at the gas stations shutting off at different levels
giving slgihtly more or less gas at one station, it still isn't a
significant change in mileage for the time saved (over half an hour). I will
say though that driving at the higher speed took more attention and left me
feeling a little more drained when I got home. Perhaps most of that was from
not sleeping much while I was in CT though.