Mileage with 19 vs 21 inch wheels - an observation

[rogbmw]

4 weeks ago I replaced my 21 inch Michelin Pilots with the OEM Goodyear 19 inch tires on T Sport rims. Interesting to note that most of the threads say that the 21's get worse mileage. I am finding out that is just the opposite of what I am seeing. When we took delivery of our S it had the OEM Goodyear 19's, which we took off in the first 200 miles and replaced them with 21 Turbines and Michelins. The Michelins wore fairly well, and I just switched back to the OEM Goodyears at 34,000 miles. It seems from what I am seeing, the 21 inch Michelins were 2% more efficient than the OEM 19 inch Goodyears. Interesting as this is opposite of most findings.

 

[ZoomFPV]

4 weeks ago I replaced my 21 inch Michelin Pilots with the OEM Goodyear 19 inch tires on T Sport rims. Interesting to note that most of the threads say that the 21's get worse mileage. I am finding out that is just the opposite of what I am seeing. When we took delivery of our S it had the OEM Goodyear 19's, which we took off in the first 200 miles and replaced them with 21 Turbines and Michelins. The Michelins wore fairly well, and I just switched back to the OEM Goodyears at 34,000 miles. It seems from what I am seeing, the 21 inch Michelins were 2% more efficient than the OEM 19 inch Goodyears. Interesting as this is opposite of most findings.

It could be the rotational weight. I will be taking delivey of my car with the 19s which I plan to pull off immediately and replace with Axis model S wheels in 21 inch. I will try to weight the wheels when I do the swap and compare mileage.

 

[JPUConn]

I read somewhere that range improves after the tires are slightly worn in

 

[Lyon]

I read somewhere that range improves after the tires are slightly worn in

This probably has something to do with it. I would recommend that OP drives a few thousand miles and then check again. Still, very interesting.

 

[brianman]

@rogbmw - It's helpful to be specific on the full name of the tires. As an example, if you search on "Michelin Pilot" at TireRack you get 444 results.

 

[rogbmw]

The tires were Pilot Super Sport http://www.tirerack.com/tires/tires...toYear=2013&autoModel=Model S&autoModClar=P85