Comparing MPGs: Tire Diameter VS Weight

This is pretty much my thought process, since this unsprung rotational weight requires more energy from the engine, due to more inertial losses, in turn lowering the MPGs. But maybe since I spend most of my time on the highway, and not so much stop and go, it may not effect me that much in general like Thatbassguy mentioned.

I am up 2” in the front and 1” in the rear, and understand that I will more than likely need some plastic trimming and CMC

I’m definitely accepting it, since I’m going up so much regardless. But if I can save a few dollars on my commute from 1-3 MPGs by choosing one size over the other, that’ll add up quite a bit over time!

 

Just some FYI. When I switched from my 50 lb+ KO2's to the 41 lb Bridgestones, my MPG absolutely went up by 2-3. Unsprung weight does matter , though not really enough to worry about.

G.

 

I might be misunderstanding your definition of "unsprung weight", but if you mean weight not supported by the suspension, it has little to do with fuel economy. IMHO, what you probably experienced is a difference in rolling resistance between the two different tires. See my previous post.

References:
https://en.wikipedia.org/wiki/Unsprung_mass
https://ecomodder.com/forum/showthread.php/effects-wheel-tire-rotational-energy-25197.html
https://www.nhtsa.gov/DOT/NHTSA/NVS/Vehicle Research & Test Center (VRTC)/ca/Tires/811154.pdf