[Covfefe]

Hey guys, summer is approaching and I have a set of summer wheels that came with the car. Right now, the 8.5" fronts have 225 tires on it, so I'm going to get rid of those asap. The rears are a 255/35r18, but when those wear out, I was thinking I would go up to a 265 and maybe go with a 40 sidewall. Is that unreasonable? My buddies e93 M3 runs 245/40r19 and 265/40r19, so I feel like 40 sidewall front and back should be okay.

Any objections to a 245/40r18 front and 255/35r18 rear before eventually going up to a 265/40r18 on the back? I don't know much about tires, so I thought I would consult the forums first.

[dradernh]

Originally Posted by Covfefe

a 265/40r18 on the back...

...is 1.5" taller than the 245/35-18 that comes on the OEM staggered set's 18X8 rear wheel. I'm guessing that could cause an issue but will defer to those who have fit 265s in the rear.

[Covfefe]

Originally Posted by dradernh

...is 1.5" taller than the 245/35-18 that comes on the OEM staggered set's 18X8 rear wheel. I'm guessing that could cause an issue but will defer to those who have fit 265s in the rear.

Originally Posted by dradernh

...is 1.5" taller than the 245/35-18 that comes on the OEM staggered set's 18X8 rear wheel. I'm guessing that could cause an issue but will defer to those who have fit 265s in the rear.

This is what I was looking for. I will go with a 35 sidewall like it is now, then.

[MassNerd]

What offset are your 9.5"? Consensus is that ET48-53 is ideal for fitting 265s.

[Covfefe]

Originally Posted by MassNerd

What offset are your 9.5"? Consensus is that ET48-53 is ideal for fitting 265s.

You know, you're right. I forgot to check the offsets of these wheels. Offsets are really small at 35 front and 45 rear.

This post shows a guy getting 35 front offset and 40 rear offset to work with 235mm in the front (instead of 245 like I hoped) and 265mm in the back. I guess a 235/40r18 and 265/35r18 would be the best setup once the 225/40r18 and 255/35r18 wear out? I've seen that 225 is very small for an 8.5" wide wheel, so I'll definitely fit a 235 if it clears.

Really glad I posted here. I have very little knowledge about wheels and tires.

[MassNerd]

I also seen people claim that ET45 worked. So let us know how it goes. I think the big test is putting two adults in the rear seats and going around turn decently fast (or over speed bumps).

I'm waiting on spring for new rims and tires. I'm putting 265s on ET58 wheels with 5mm spacers (so ET53 in the end). If the ET45s work, then I'll be wishing I went that way for a more flush look!

[POMFKIMOCHI]

Sorry for the slight takeover but I was also looking to up my sidewall thickness with a new set, I hit a pothole on the 401 that blew out one of my rears. The roads in Toronto really aren't suitable for most low profile performance tires, so I obviously don't want to get a new set that I like and risk damaging the rims with another blowout. Ideally I'd want at least 40 like yourself buuut I think 45 would be safest, and I am obviously cognisant of the restrictions we face with the f22 platform. I am completely stock suspension atm but does anyone know/have an optimal setup for thicker sidewalls as well as the usual increase in width will still maintaining a degree of comfort along with use of the dampeners? I would be open to reducing 17s or making any other changes if required, but I'll need at least 235/255s with a Y speed rating at the very minimum as well (anything less isn't really an upgrade). I was looking to do the LCA/TS swap, but if there's alternatives/better setups for thicker tires with thicker sidewalls then I am all ears. Thanks in advance!!

[dradernh]

Originally Posted by POMFKIMOCHI

I think 45 would be safest, and I am obviously cognisant of the restrictions we face with the f22 platform.

I would be open to reducing 17s or making any other changes if required, but I'll need at least 235/255s with a Y speed rating at the very minimum as well (anything less isn't really an upgrade).

From Tire Rack's site, here are diameters for some 17" 45-aspect ratio tires:

235/45-17 25.4" Michelin PS4S
245/45-17 25.7" Michelin PS4S
255/45-17 26.0" Continental ECS.

The Continental is only a W-rated tire, but our cars don't go fast enough for it to matter. Or, if yours does, you'd probably have to run it at an event like the Silver State Classic Challenge before the W-vs.-Y speed rating would make a difference. My 2¢, of course.

The OEM rear tire is 24.7" in diameter, so you might have to adjust camber and/or roll the rear fender to fit a taller tire. Someone who has fit a taller tire in the rear may be able to tell you how tall a tire you can fit, and what had to be done to fit it (if anything). I've only gone up to a 25.0" diameter rear tire, and while a 5mm spacer, negative camber, and rolled fenders were part of the build back there, I don't know if the 0.3" difference in diameter required any of those modifications.

[B58togo]

Originally Posted by MassNerd

I also seen people claim that ET45 worked. So let us know how it goes. I think the big test is putting two adults in the rear seats and going around turn decently fast (or over speed bumps).

I'm waiting on spring for new rims and tires. I'm putting 265s on ET58 wheels with 5mm spacers (so ET53 in the end). If the ET45s work, then I'll be wishing I went that way for a more flush look!

I’m on 9.5 ET58 with 5mm spacers and I’m pretty flush with 265 PS4S.