The quest for a good wheel/tire setup?

[fatoni]

Originally Posted by ZDan

9" is wider than the maximum recommended wheel width of 8.5" for 225/45-17 tire size (for any tire make/model I'm seeing, anyway). To me, that makes it a STRETCH by definition.


225/45 on a 9" might be quicker and put up better handling numbers vs. 225/45 on an 8", BUT on a given 9" wheel, 245/40-17 is going to be quicker around just about any autoX or road course than 225/45-17 of the same make/model tire. And it will look better (subjective).

Also, it's not ONLY about absolute lap times.
OP said: I daily drive the car but would like to take it to some track days and drift it and enjoy my self.

Daily driver, not competing where tenths matter. Besides being a lower-performing option on 9" wheels vs. 245/40-17 and being outside tire manufacturer's recommendations for fitment, 225/45-17s on 9" will leave the wheels more susceptible to curbing due to the stretch. Rim will hit the curb way before the tire's "rim protector".
And it looks dumb (subjective).

For OP's usage, I'd actually still prefer 245/40-17 on 8.5" wheels. This is the street fitment I have on the front of my FD. If I were to run 225/45s on the street, I would want 7.5" wheels. Personal preference based on not being a fan of any stretchie look at all and also in order to protect the rims better against curbing.

you can pick whatever definition of stretched you want but i think its important to note that its changing. tire rack historically wont mount a tire that isnt recommended but they will for the 225 on a 9" rim now. we can call it stretched if you want. it doesnt change what is happening.

im from the camp where i pick a tire size and use the best rim. not the reverse. even if i wasnt, i dont think a 245 street tire is faster on a road course but it probably will be at an autox if its the right tire. the curb rash thing is a legitimate concern but i think its a small price to pay to have the faster, more responsive setup.

[ZDan]

Originally Posted by fatoni

you can pick whatever definition of stretched you want but i think its important to note that its changing. tire rack historically wont mount a tire that isnt recommended but they will for the 225 on a 9" rim now. we can call it stretched if you want. it doesnt change what is happening.

Tire Rack doesn't specify recommended rim widths for tires. Tire manufacturers do. That's why (on rare occasions) some tires of the same size have different approved rim widths.

Run 225/45-17s on 9" wheels, you are outside the tire manufacturer's spec.

im from the camp where i pick a tire size and use the best rim. not the reverse.

Yes, I recognize your approach, you INSIST that to get the best out of a given tire you MUST run it on the absolute widest rim you can! But this ignores other real-world concerns *and* the fact if you run the WIDEST possible tire on a given rim width you will probably be FASTER than if you run the NARROWEST possible tire on the same given rim width.

even if i wasnt, i dont think a 245 street tire is faster on a road course but it probably will be at an autox if its the right tire.

I would bet money that 245/40-17 will be faster vs. 215/45-17, same make/model tire, under most conditions at most tracks on 17x9" wheels.

the curb rash thing is a legitimate concern but i think its a small price to pay to have the faster, more responsive setup.

225/45-17 on 17x9 won't be FASTER than 245/40-17 on the same wheels. Also, for the OP's usage, I think that even if there were a couple of tenths in lap time from stretching narrower tires on a given rim width (which I don't for a minute concede) that it wouldn't be worth it!

For a street tire, 225/45-17 on a 17x9" tire is stupid. It's slower, and it makes rims much more susceptible to damage. If you like the stretched look, fine. But don't pretend it's for any real performance advantage.

[86-tundra]

Originally Posted by Boofneenee

Go light weight for improved performance. Just picked up some used rims 17" that weight 4 lbs less than stock. Using stock tires. I cant believe how much more responsive and just quicker the car has become. If u can find 18 that are light i guess that will be good as well. Will look better for sure but expect to drop big money as ure gonna hve to get tires with that.

This.

i'm running 17x8" wheels that weigh 18lbs (stock tires still), and there really does seem to be a difference.

[koyv90]

Originally Posted by ZDan

9" is wider than the maximum recommended wheel width of 8.5" for 225/45-17 tire size (for any tire make/model I'm seeing, anyway). To me, that makes it a STRETCH by definition.


225/45 on a 9" might be quicker and put up better handling numbers vs. 225/45 on an 8", BUT on a given 9" wheel, 245/40-17 is going to be quicker around just about any autoX or road course than 225/45-17 of the same make/model tire. And it will look better (subjective).

Also, it's not ONLY about absolute lap times.
OP said: I daily drive the car but would like to take it to some track days and drift it and enjoy my self.

Daily driver, not competing where tenths matter. Besides being a lower-performing option on 9" wheels vs. 245/40-17 and being outside tire manufacturer's recommendations for fitment, 225/45-17s on 9" will leave the wheels more susceptible to curbing due to the stretch. Rim will hit the curb way before the tire's "rim protector".
And it looks dumb (subjective).

For OP's usage, I'd actually still prefer 245/40-17 on 8.5" wheels. This is the street fitment I have on the front of my FD. If I were to run 225/45s on the street, I would want 7.5" wheels. Personal preference based on not being a fan of any stretchie look at all and also in order to protect the rims better against curbing.

The wheels im looking at come with 225/45 they don't look that bad but i will definitely look into 245/40 when changing tires. Want to try both !

[fatoni]

Originally Posted by ZDan

Tire Rack doesn't specify recommended rim widths for tires. Tire manufacturers do. That's why (on rare occasions) some tires of the same size have different approved rim widths.

Run 225/45-17s on 9" wheels, you are outside the tire manufacturer's spec.

Yes, I recognize your approach, you INSIST that to get the best out of a given tire you MUST run it on the absolute widest rim you can! But this ignores other real-world concerns *and* the fact if you run the WIDEST possible tire on a given rim width you will probably be FASTER than if you run the NARROWEST possible tire on the same given rim width.

I would bet money that 245/40-17 will be faster vs. 215/45-17, same make/model tire, under most conditions at most tracks on 17x9" wheels.

225/45-17 on 17x9 won't be FASTER than 245/40-17 on the same wheels. Also, for the OP's usage, I think that even if there were a couple of tenths in lap time from stretching narrower tires on a given rim width (which I don't for a minute concede) that it wouldn't be worth it!

For a street tire, 225/45-17 on a 17x9" tire is stupid. It's slower, and it makes rims much more susceptible to damage. If you like the stretched look, fine. But don't pretend it's for any real performance advantage.

i know tire rack doesnt recommend settings but they wont mount a tire to a rim in an unsafe manner. they will however mount a 225 to a 9 inch rim.

while i think the widest appropriate rim for a given tire, i dont think the widest tire is as often the fastest. even a lot of the forced induction guys arent running much more than a 245 and thats probably an appropriate size tire for the track but i guess the car is young and the jury is till out.

im not pretending anything. youve brought up before that the op isnt buildling a track car. he brought up 225 and 255. i think the 225 would be faster and more affordable so thats the choice i would make from the two. within the 225 conversation, i think the nine inch rim is faster.