i have a 2012 prius c with 72k miles. when i bought teh car, it took a while for the fuel economy to increase. i drive 100 miles a day at 85mph and topped out at 52mpg. pretty damn good, if you ask me. im all interstate with very little city driving. 2 years later, its time to get new tires and ever since i changed them, my fuel economy has decreased to 45mpg. i plan to give it a few weeks to see if it increases but I was wondering if anyone else has had this problem. my new tires are goodyear fuelmax assurance - supposed to be great for fuel economy.
I changed my tires to Hankook's Optimo H426 or whatever they're called. Cheap tires because I am not keeping the car for long. I'm down about 4 mpg on average.
A decrease is normal after a tire change. Part of the decrease is due to a difference in circumference between the old and and new tires.
As I understand, there are two tires used as OE for the Prius C in the US. I got mine with the Goodyear Assurance Fuelmax from the dealer (as a new car.)
Somewhere on this forum, there's an "ultimate tire guide" thread. It mentions that 2 Michelin tires are the best for fuel economy at 15" and 17" wheel sizes. I may consider those next time I need tires, but you got what Toyota felt are the right choice for the car with respect to a good balance between ride/handling, fuel economy, and noise. Good choice!
I tried to find it but couldn't in the short time I had. I'm hoping someone who knows where it is will link it.
I posted a link here, I hope it's the right one. BTW, I think my MPG decreased after changing to Ecopia EP422 but they're much more quiet than the original tires.
Switched to Ecopia EP422's as well. Much quieter tire. I have them set at 35 PSI, and get between 400-420 miles on a tank. (I fill up when I get low gas warning beep). They have a soft sidewall so you get that weird cushy/spongy feel when turning. Might increase to 38 PSI and see how things turn out.
its not normal unless you change tire size. The only change we see here with literally thousands of new tire changes is you can expect less mpg only if you mount heavier tires or go bigger on tire diameter. Mount narrower tires of same size with less weight and you will increase mpg. Thats why you go slightly smaller tires when the choice is extra width, If your mpg decreases its because the new tires are bigger thanks to more tread but its not statistically verified. Its merely because the tire weight has changed or in rare cases a tread design will change mpg but thats due to aggressive treads that aren't smooth and round. And don't forget that you may have to change tire pressures to get same results. Use the spec data on tire rack.com to get the dimensions, weights, and revs per mile to get good comparision. While you're at it check their buyer opinions and performance data. Its like everything else. research counts. And yes as you wear the trad it often, but not guarnteed to get better but its not really actual data. the tire rotates smoother with less rolling resistance but naturally more often per mile so your odometer thinks is going further between fillups. Not really that significant. You'll have more result with a good waxing. Really, just ask the salt flat racers. Or NASCAR.
