Gas Milage Change on sizing up to 225/45/18?

[Guntherjds]

I'm looking at putting Falken 452 or Sumitomo HTR Z III on my stock wheels.(both 225/45/18) Does anybody know how much change this would cause in my gas milage? My Speed is stock except for a Cobb SRI. If its gonna be a big change or there are other reasons to not size up, then I'm guessing I am petty limited to going with the Kumho Ecsta SPT 215/45/18. Your thoughts? Advice? I need new tires and need some wisdom. I do not want to hurt my gas milage.

Thanks for your help.

 

[mr_mazda329]

The new tires are about 1lbs heavier than the stock ones. You gas mileage may go down or stay them same. The gear ratio will slightly get taller due to this size. Also the extra rollling resistance with it being a wider tire to.

 

[StealthWyvern]

I highly doubt you would see any difference in your mileage thats noticeable.

 

[Guntherjds]

Thanks.

So is it going to effect power as well, or are we talking a really really minor effect? Is the 225/40/18 a better way to go? You guys have preference on the tires listed? Sorry I'm new to alot of this stuff,I catch on quick though. I appreciate the help.

 

[mr_mazda329]

Both tires are really good gripping UHP tires. Good for rain and dry. Good tread life too. I say go with the 225 45. Thats what I'm going with once I buy them for my new wheels.

 

[builthatch]

Both tires are really good gripping UHP tires. Good for rain and dry. Good tread life too. I say go with the 225 45. Thats what I'm going with once I buy them for my new wheels.

if you won't see any slush/snow, i'd say get falken azenis 615. they are the best street tires IMO, period. a bonus is that they are not necessarily that expensive either. they are just fine in the rain despite what anyone might say, however, they of course won't be as capable as some other options in torrential downpours while driving at high speeds ; )

the downside is tread life, but the performance is just so wonderful, i think it's worth it. just rotate often and save the tire spinnin' for when you really mean it.

to be honest, i'd say you won't notice anything from the change, period, other than the speedometer being off by ~.5 to 1 mph during the course of normal driving speeds : )

 

[mr_mazda329]

i'd say get falken azenis 615. they are the best street tires IMO, period.

The exact tires I am getting too. I wont go as far as the best street tire due to that they can get real greasy at the track, but for the price, hells yea they are. The Toyo R1R's and RE-01R's are currently stomping the RT-615's for street tires used at AutoX by about 1.2 seconds for a 60second course on average. But those tires are super pricy

 

[builthatch]

The exact tires I am getting too. I wont go as far as the best street tire due to that they can get real greasy at the track, but for the price, hells yea they are. The Toyo R1R's and RE-01R's are currently stomping the RT-615's for street tires used at AutoX by about 1.2 seconds for a 60second course on average. But those tires are super pricy

yeah def. i'd never spend over 225 a corner on this car with daily driven soft tires, ESP if i planned on auto-x on the same tires...it'd just be money down the drain.

save the r1r for the course, where you will get the most out of your investment over the course of a season. 615 is right at home on the street and if you wear them out, you'll be paying substantially less than what the other tires command.