[84porsche]

I tend to drive 10 to 15 mph over on back roads on my way to work. But on twistes, I prefer to stay with the posted speed limit or a few miles over as I really don't know the roads. If I know the road and I have driven it several times then 10-15 mph over is fine. However, I usually only drive extreme fast if I know that the roads are clear of pedestrians and other cars, basically a place with no side streets or schools etc.

It's funny this question came up because I was thinking about how fast over I usually drive and if I slow down will I improve my gas mileage.?