Originally Posted by StephenVA

There are so many thoughts on this issue left over from the 70's fuel crisis (for all you youngsters that was when the Gov got involved in gasoline distribution as fuel prices reached ...gasp $.50 @ us gallon).
Best practices... Use the hills to your advantage. speed up on way down and slow down on way up.
Acceleration... Burns more fuel than anything other than a cold start up. Slow, easy, allowing the trans to get in to higher gear will give you all there is to gain.
coasting.... In gear or out of gear? Out of gear allows you to speed up with out engine involvement. You are left only with rolling and air resistance. The fuel is cut off when coasting in gear but the drivetrain will slow you down REAL QUICK.
Now the real questions should be "What is the wear on an auto trans when coasting in neutral, if any?"
For those of us who do not give a rats ass other than to say "hey, it is double digits!" I say hard acceleration is why we own the V8's with fat tires.
If you want fuel economy sell it and buy a 4 cyl whatever, with skinny tires and a manual trans. I personally use my Vespa to run to the post office and the bank. Early mornings only on weekend as I do not care to become a bumper ornament on a texting idiot's Honda.