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[hdrewh]

I've decided on an 18x8.5 square setup, most likely Apex ARC-8's, identical tires all around.

I'm in semi-upstate NY and would like a little taller profile than the standard 225/40-18, for some added protection against potholes.

Would 235/40 work?

'09 E90 without sport package *but* will be installing sport springs and Koni FSDs when I get new wheels, so the car will be ZSP height.

Thanks.

[Msport335]

You should have no problem with that setup. If you can hold off from buying for now, apex should be having their group buy on the arc-8's in a couple months in order to save some dough

[Gary@TireRack]

235/40R18 is a pretty common size to use by guys up here. I would not expect you to have any problems.

Tires http://www.tirerack.com/a.jsp?a=AH8&...ires/index.jsp

[Nitrous Garage]

The 235/40 will work perfectly. Shoot me a PM for a quote on Apex wheels

[hdrewh]

235/40R18 is a pretty common size

The 235/40 will work perfectly

Thanks for the replies.

I'm seeing now that 255/35 is the OEM size for 18x18.5 wheels, so shouldn't I be looking at the 255 width and 255/40 for a slightly taller profile, on 18x8.5" rims?

That would be an ideal size, but it depends on the tire, alignment specs, etc. Since you're going to be lowering the car as well, you might end up rubbing as the tire will sit rather tall with your proposed configuration.

[Expert@ApexWheels]

The 235/40/18 definitely works with the 18x8.5" wheel, and is a rather popular tire size for that wheel. Here are two different cars using the 18x8.5" wheel with 235/40/18 tire size:


18x8.5" ET35 and 18x10" ET43 EC-7's wrapped in 235/40/18 and 265/35/18 Hankook V12.


18x8.5" ET38 and 18x9.5" ET35 ARC-8's wrapped in 235/40/18 & 265/35/18 Sumitomo HTR ZII.

[jon_335]

Originally Posted by hdrewh

Thanks for the replies.

I'm seeing now that 255/35 is the OEM size for 18x18.5 wheels, so shouldn't I be looking at the 255 width and 255/40 for a slightly taller profile, on 18x8.5" rims?

255/35 is the standard for the rear tires. I'm not sure that a 255 would fit up front. Someone, please correct me if I'm wrong. And, of course, if you go with a taller tire, your speedo will read incorrectly (you'd be changing the overall diameter).

Originally Posted by jon_335

And, of course, if you go with a taller tire, your speedo will read incorrectly (you'd be changing the overall diameter).

False. If anything, my speedo now is now closer to actual speed (GPS verified).

[jon_335]

Originally Posted by FCobra94

False. If anything, my speedo now is now closer to actual speed (GPS verified).

According to willtheyfit.com, going from a 35 profile to a 40 profile will cause a -3.8% reading in your speedo. Granted, the speedo is programmed to read a little high.

[VMRWheels]

Originally Posted by hdrewh

Thanks for the replies.

I'm seeing now that 255/35 is the OEM size for 18x18.5 wheels, so shouldn't I be looking at the 255 width and 255/40 for a slightly taller profile, on 18x8.5" rims?

The middle number is a percentage, so a 255/40/18 is going to also be taller than a 235/40/18. Stick with a 235/40/18. 255/40/18 is too tall.

Originally Posted by jon_335

According to willtheyfit.com, going from a 35 profile to a 40 profile will cause a -3.8% reading in your speedo. Granted, the speedo is programmed to read a little high.

Correct; about 5% too high. Hence my previous reply.

[AutoGuy1314]

Originally Posted by hdrewh

I've decided on an 18x8.5 square setup, most likely Apex ARC-8's, identical tires all around.

I'm in semi-upstate NY and would like a little taller profile than the standard 225/40-18, for some added protection against potholes.

Would 235/40 work?

'09 E90 without sport package *but* will be installing sport springs and Koni FSDs when I get new wheels, so the car will be ZSP height.

Thanks.

Great choice on the wheels. What tires are you planning to get?