245/40 vs 245/35

[NorCal_B7]

Has anybody run 245/35 tires on 18x8" wheels? My stock tires are 235/40 and I'm looking to upgrade to 245s, but I'm not sure if 35 or 40 works better with that width. Looking for opinions about track performance too, if anybody has experience with either ratio.

Thanks

Edit: stock tires are 235/40R18 not 235/45R18

[Firefox250]

I run Toyo R888 235/40R18 on a 18x8.5 ET35 with rolled finders and -1 camber and I'm 25" from fender to ground. I don't have any rubbing but damn track tires are WIDE!

[NorCal_B7]

How do you like the 45 profile ratio on your setup? With a 235 tire, that puts the thickness at around 105mm... which is 20mm more than a 245/35!

[Firefox250]

Ooops I meant 235/40R18

[Van Black]

245/35/R18 are 2.4% smaller in diameter than the 235/40/R18, that means a bit more acceleration by sacrificing maximum speed in any given gear.
How come you're running 235/45? The 40s are recommended for B7s on 18"?

[NorCal_B7]

Oops, like firefox here I didn't even notice that I wrote 235/45. That should be 235/40... like you said, the recommended tire size for 18" B7 wheels.

A little more acceleration would be a nice byproduct of the 245/35s, but I'm mainly looking for handling benefits. Not sure if the 40 vs 35 will really reduce tire roll-over in hard corners, but I thought I'd see if anyone has experience running them.

[canadianA4B7]

I'm running 245 40r18. Never had any issues or concerns going into or out of corners. I'm 2.5 degrees camber all 4 tires. Anmbout the same height at Firefox and no rubbing that I've ever noticed, no rolled fenders just the front upper screws removed from fender liner. I think et 35 front, et 30 rears.

[miA4]

I'm 245/40/18 and have slight rubbing in the passenger rear tire going over some crazy bumps. other than that, no issues. my rims are +48 I believe as well.

[NorCal_B7]

Are you guys running on 8" or 8.5" wide wheels?

[vvenom800tt]

245/35/19
245/40/18
245/45/17

End thread/

[Charles.waite]

235/40 tires shouldn't have any appreciable roll in hard cornering, assuming you have properly specced sidewall ratings.

I wouldn't consider 245s crammed on 18x8s as an "upgrade" either. you get more meat, but when the width of the tire exceeds the width of the wheel, the contact patch can wobble side to side and in theory could degrade handling and traction.

Also, though, its only 1/2" so realistically you're not going to gain any sort of appreciable traction on the road by doing this. You're MUCH better off spending a bit more coin on better tires at the appropriate size than you are oversizing tires...

For instance get some Michelin/Bridgestone Max Perf Summer tires at 235/40/18 and tell me that they don't have enough traction for your needs...

[NorCal_B7]

I wouldn't consider 245s crammed on 18x8s as an "upgrade" either. you get more meat, but when the width of the tire exceeds the width of the wheel, the contact patch can wobble side to side and in theory could degrade handling and traction.

Also, though, its only 1/2" so realistically you're not going to gain any sort of appreciable traction on the road by doing this. You're MUCH better off spending a bit more coin on better tires at the appropriate size than you are oversizing tires...

This is what I was looking for. I guess I assumed 245 width would be better for dry handling since it's wider than 235, but your post makes sense given the other factors at play. 235/40s seem to be a little cheaper than 245/40s too (for the same tire anyway).

Thanks for the input

[b7_Andy]

265/35R18 on 9.5" wheel... Do it.


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[miA4]

Are you guys running on 8" or 8.5" wide wheels?

I believe mine are 8.5"

[yeoj112689]

I ran 265/30/r19's and honestly they were great. I had a bit of rubbing on the outer wall when my rear subframe wasn't aligned but nothing too horrible. They were super wide though so be aware. I ran 245's in the front. No way the 265 would have fit.

[b7_Andy]

I ran 265/30/r19's and honestly they were great. I had a bit of rubbing on the outer wall when my rear subframe wasn't aligned but nothing too horrible. They were super wide though so be aware. I ran 245's in the front. No way the 265 would have fit.

I'm thinking of running the same size tire setup. With the right wheel offset, camber adjusted, and a fender guy that know his shiz, I plan on getting 265s all around.

[o1turbo30v]

I run 245/35/19 on a 19x8.5 ET 35 on my lowered avant with no issues, keep the 18' s for winters and go 19's.

[b7_Andy]

I run 245/35/19 on a 19x8.5 ET 35 on my lowered avant with no issues, keep the 18' s for winters and go 19's.

I have the same size wheels. I originally tried 245/35R19s, my buddy rolled all the fenders and they still rubbed... Too much that I didn't want to drive it like that. He said they could fit if he pulled the fenders a good amount but I wasn't feeling it at the time so just slapped on some 235s and there's no rubbing at all. Have you adjusted for a good amount of camber or have you had fender work done?

[o1turbo30v]

I have the same size wheels. I originally tried 245/35R19s, my buddy rolled all the fenders and they still rubbed... Too much that I didn't want to drive it like that. He said they could fit if he pulled the fenders a good amount but I wasn't feeling it at the time so just slapped on some 235s and there's no rubbing at all. Have you adjusted for a good amount of camber or have you had fender work done?

Did nothing to the rear, the front i only removed the fender liner bolt that's on the bottom lip of the fender, no rolling, pulling, cutting, trimming, etc. Lowered about 1.5" on Eibach springs with Bilstein Sports. Its a close fit so maybe your tires you had carried a slightly wider profile than my Pirellis. My Pirellis had a very slight stretch on the 8.5 wide wheel that's why i think they work.

[b7_Andy]

Did nothing to the rear, the front i only removed the fender liner bolt that's on the bottom lip of the fender, no rolling, pulling, cutting, trimming, etc. Lowered about 1.5" on Eibach springs with Bilstein Sports. Its a close fit so maybe your tires you had carried a slightly wider profile than my Pirellis. My Pirellis had a very slight stretch on the 8.5 wide wheel that's why i think they work.

My 235s have a slight stretch. My 245s looked pretty beefy as seen in the picture