Do higher tire walls affect milage / efficiency?

[Stijn_NL]

I was wondering whether tires with higher walls affect efficiency.

For example, mounting a 255/50 instead of a stock 255/45. Same rim radius (inches).

I’m asking this because the wheel to fender gap on a Model Y is a tas large and it’s confirmed the 50’s fit.

My reasoning is there is a small negative difference. The contact patch grows ever so slightly (because of the larger circumference) which increases rolling resistance and the car is lifted further off the ground, which allows more air to pass under the car (which is usually not a good thing for efficiency).

I only read people who did this for winter tires and have noted reduced range, but these numbers are mixed in with the fact that winter tires use more energy anyway.

I’m also looking to do this with my summer tires for looks. Anyone with experience?

 

[ATPMSD]

The speedometer is tied to a known tire radius. If you put on taller tires you will be traveling slightly faster than what it shows. Faster means higher drag and thus reduced range.