Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Oversize tires? (higher sidewalls, but still as skinny as possible)

busypaws · 05-01-2010, 12:08 PM

Haven't done any A-B-A testing but I didn't see it with my 95 Toyota PU. Stock tires are 195/75/R14. First time I changed to 205/75/14. So I went a little wider and a little taller. Did not see a change in fuel. Then 40K later I went 215/75/r15. So I bought new steel rims. Now my Spedo is off by 8% so I have to remember that when going through the auto camera speed traps. Again no noticable change in mpg. I can say that the interstate here in AZ is 75 and now I can go 65 on spedo which is really 70 and not feel like the engine is too high RPM. Also 70 in 75 zone doesn't piss off too many people.
I think the real answer is trying to find taller tires that don't also increase width. If you are already at 75 ratio then you can't really go any taller without also going wider and heavier.

05-01-2010, 12:08 PM	#3 (permalink)
busypaws EcoModding Apprentice Join Date: Jul 2009 Location: Live in Tucson AZ, work and car now in Detroit Posts: 200 Protege - '97 Mazda Protege DX 90 day: 46.42 mpg (US) Thanks: 13 Thanked 23 Times in 18 Posts	Haven't done any A-B-A testing but I didn't see it with my 95 Toyota PU. Stock tires are 195/75/R14. First time I changed to 205/75/14. So I went a little wider and a little taller. Did not see a change in fuel. Then 40K later I went 215/75/r15. So I bought new steel rims. Now my Spedo is off by 8% so I have to remember that when going through the auto camera speed traps. Again no noticable change in mpg. I can say that the interstate here in AZ is 75 and now I can go 65 on spedo which is really 70 and not feel like the engine is too high RPM. Also 70 in 75 zone doesn't piss off too many people. I think the real answer is trying to find taller tires that don't also increase width. If you are already at 75 ratio then you can't really go any taller without also going wider and heavier.