Road surface effect on mpg

[herektir]

Any anecdotal stories about your experiences with road surface changes that has effected your tank to tank average mpg? Mine is that in the last 2 weeks a 12 mile stretch of my rural route home was resurfaced with a larger rougher gravel. That portion of my trip mpg went from 56 to 58 mpg(some good coasts on that part) down to 51 mpg. Overall effect is morning commutes went from 53.5 avg down to 51. Evening return 57 mpg down to 53-54.

Almost makes it worth it for the faster highway route now despite the even lower average I’ll get. Save 7 or 8 minutes but lose 1 or 2 mpg vs what used to be losing 4 or 5 mpg for the highway route.

The actual coasts down hill used to net me a gain of 3 mph now barely hold speed. I also now also lose speed on the shallower coasts which used to maintain my mph to within 1 mph.

Any other stories of route changes for similar reasons?

[oil pan 4]

No not anecdotal.
I have seen an actual DoE or EIA chart showing how different road surfaces effect fuel economy. Smooth polished concrete was the best by far.

[freebeard]

Any other stories of route changes for similar reasons?

Every year people congregate to test their cars against the poorest surface on the planet — The Salt. I went 1300 miles out of my way just to watch.

[Daschicken]

Cummins has a white paper on truck mpg. In there, they detailed the effects of road surface on mpg. Thankfully, this paper is not only easy to find, but free!


https://minutemantrucks.files.wordpr...whitepaper.pdf

Page 26 has what you seek....

[mpg_numbers_guy]

I haven't really noticed a difference in MPG on paved roads that can be attributed to the road type, but the dirt road I live on is horrible when freshly grated or graveled, both for driving on and for biking. It's worth it to reduce the washboarding and potholes that tend to creep up but driving on it for the first day or two is horrible for coasting and efficient driving.