Quote:
Originally Posted by oldtamiyaphile
According to Cummins, the difference in CRR between smooth polished concrete and chip and seal blacktop is 45%. As a rule of thumb if you can hear your tyres roaring against the road surface, your MPG is suffering.
Stick to where it's polished smooth  |
Except that traffic generally does not polish the surface, but roughens it. Especially with concrete, as the cement is worn away, exposing the rougher aggregate.
With the Insight's instant mpg gauge, I can definitely see a difference between the ridges & ruts, and between different road surfaces.