This year I have been driving on 100% gas and with that I am able to get much more accurate mpg readings than relying on the guess o meter to tell me how many electric miles I have to subtract. I switched from my Michelin X-Ice snow tires to the OEM tires over 2 weeks ago now and have put 2 tanks of gas in since the switchover. Amazingly I found no discernible difference in mileage between the last few tanks on snow tires and the 2 on OEMs. All the tanks were between 39 and 41 mpg under similar driving and weather conditions. I did use -1 tires at the 17" wheel size so perhaps that reduces friction a bit but the result is still surprising. FYI both tires list the same diameter of 26.3" so there should be no ratio changes influencing this result. So I think when my OEM tires wear out I'm just going to go with something more reasonably priced than the expensive Michelin OEMs. Anyone with good data on mpg with alternate All Season tires?
The Tire Rack reports mpg differences among tires they test. That’s perhaps your best source of data, since they have run many different tires through their testing protocol. I just used their site for info and ordered tires mounted on wheels for another vehicle. They showed up on my porch the next day, mounted and road forced balanced for free and with free shipping.
Others in this forum have also noticed no dramatic difference when using non-OEM tires (but usually see a bit worse). I think the conventional wisdom is that snow tires do a bit worse than A/S tires because of their softer compounds. The lack of a difference in your case is probably the narrower width of your snow tires. I was surprised Honda decided to install such wide tires on the Clarity (the base Kia Stinger, a sports sedan, has narrower tires) but I'm glad for the better handling they provide. There is a significant mileage improvement with narrower tires. That's why the high gas mileage versions of hybrid vehicles always have narrower tires than the other trims.
