Oversize tire fitment questions

[Iroc_g]

I am finally getting ready to order rims and tires for my 97 gsx, and have settled on a 18 x 7.5 rim. Rims are 42mm offset.

After looking at a few other eclipses, i really thing that the 225-40x18 that most places seem to recomending isn't enough tire. There just isn't enough sidewall there.

So, I am trying to consider a few options, eiter simply getting a taller 225 tire, or getting a wider tire in either the 40 or the 45. I know i may need spacers to accomplish this. I like the idea of a wider tire, but i don't want to over do the rim size too much either.

I am willing to give up a little speedo accuracy because i think ot will be far worth it in handling and ride quality.

And yes, i know that 17's would solve this, but i really think 18's will look better, and i am planning a large break upgrade in the spring for autocrossing.

 

[wret]

The rim width you have chosen limits you to a 225 width max. I think you could fit 225/45/18's but don't quote me on it. If you plan to autocross you will probably not want to give up that much torque.

 

[Nighthawk01]

I am finally getting ready to order rims and tires for my 97 gsx, and have settled on a 18 x 7.5 rim. Rims are 42mm offset.

After looking at a few other eclipses, i really thing that the 225-40x18 that most places seem to recomending isn't enough tire. There just isn't enough sidewall there.

So, I am trying to consider a few options, eiter simply getting a taller 225 tire, or getting a wider tire in either the 40 or the 45. I know i may need spacers to accomplish this. I like the idea of a wider tire, but i don't want to over do the rim size too much either.

I am willing to give up a little speedo accuracy because i think ot will be far worth it in handling and ride quality.

And yes, i know that 17's would solve this, but i really think 18's will look better, and i am planning a large break upgrade in the spring for autocrossing.

i am running 225/40/18's on 18X8.5 wheels. on my stock suspension 91 tsi.

 

[Iroc_g]

Nighthawk... Thanks for the input, but youre kinda going the other way that im trying to. I want more sidewall.

Wret... I have looked around, and im thinking that a 235/40-18 would fit the rim. If youre running 245's, im pretty sure that wont rub.

I might be over worrying this a little, i spent some time looking through the galleries at cars with 225/40-18's on them. They didn't look like there was too little sidewall. But i saw a guy with that size on his 2g, and i was amazed at how little there was. But, i didn't think to see if he had stretched them onto an 8.5" wheel like nighthawk.

Wret, what have you found is the best combination for autoX? That is probably what i will use this car for mostly. If it is worth me trying to find annother wheel i like that is 8 or 8.5, maybe ill just have to do that. What kind of tires are you tracking with as well?

 

[definitiveno]

Nighthawk... Thanks for the input, but youre kinda going the other way that im trying to. I want more sidewall.

Wret... I have looked around, and im thinking that a 235/40-18 would fit the rim. If youre running 245's, im pretty sure that wont rub.

I might be over worrying this a little, i spent some time looking through the galleries at cars with 225/40-18's on them. They didn't look like there was too little sidewall. But i saw a guy with that size on his 2g, and i was amazed at how little there was. But, i didn't think to see if he had stretched them onto an 8.5" wheel like nighthawk.

Wret, what have you found is the best combination for autoX? That is probably what i will use this car for mostly. If it is worth me trying to find annother wheel i like that is 8 or 8.5, maybe ill just have to do that. What kind of tires are you tracking with as well?

Wret is kind of the final say on what will or won't fit, it's a combination of your wheel diameter and offset why wret said "might fit" and the wheel width as to why you shouldn't run 235's. You will be rubbing on your control arm and comprimising the sidewall streangth of your tire.


Why would you want to do all that? Wret doesn't just like to type, he knows his wheel fitment

 

[jetdriven]

I just put a set of EVO VIII wheels with the stock evo tire size 245/40/17. clearance is not a problem except if you go over some serious dips in the road the front tires will rub the edge of the fender. I have no idea how to cure that.

 

[wret]

Wret is kind of the final say on what will or won't fit, it's a combination of your wheel diameter and offset why wret said "might fit" and the wheel width as to why you shouldn't run 235's. You will be rubbing on your control arm and comprimising the sidewall streangth of your tire.


Why would you want to do all that? Wret doesn't just like to type, he knows his wheel fitment

Thanks for the vote of confidence, Definitiveno. Actually I think 225/45/18's will fit. I just didn't want to sound too enthusiastic about it. Those tires are something like 4% taller than stock and autocrossing was mentioned. We are somewhat torque challenged already in autocrossing and that will make things worse. Serious autocrossers tend to go the other way with tires that are somewhat shorter than stock to gain some torque.

I also think that 235/40/18's will fit, technically speaking, but I wouldn't put them on a 7.5 inch wheel and 7.5 inches is below manufactures recommendations for 235/40/18's, at least the ones I'm most familiar with. And again, when it comes to handling, wider is better.

The real resident expert here, when comes to what works for autocrossing, is jtmcinder. I don't think I've yet heard him stray from his opinion that 245/40/17 is the best size for a mildly serious autocrosser. I'm a little on-the-fence right now concerning my next wheel purchase, but this is more of a decision about whether or not they will see much road duty. If I were to buy a set of wheels today that were to be daily driven and take me around the autocross course, ideally they would be 17x8.5 and +40mm offset and weigh less than 18 lbs. each. (See recent lightweight wheels thread).

 

[Iroc_g]

Sorry to revive an old thread, but i have a new question. Since the rim i am looking at seems to be causing more problems than the savings are worth i have started looking for new wheels. If i were to run an 18 x 8.5, what would the recomended tire size and offset? Also, If anyone has this setup, opinions on their tire purchaces!

thanks

 

[Big28 2gFWD]

with the offset u've got piced out 245's will rub against the fender well(known from experience) with a im runnin 235/45/18's on my 2g fwd +40mm offset, 1/8" wheel gap and i clear with no rubbing anywhere