I have a 2003 Touring 6 speed. I need new rear tires but want something wider. If i buy 275/40/18's off the internet and then take them somewhere to have them installed, will tire shops give me grief about installing them since they arent original equipment spec? It shouldnt be an issue but in this day in time with law-suits and stuff, you gotta ask.

 

depends on the rims. 275/40/18's on the rear are fine on a 9.5" aftermarket rim.

 

better find a good shop, 275 may be pushing the limit of the 6 spoke 18's

 

I looked around on here and everyone says that 275/40/18 is the widest you can go on the stock? If not, what is the widest and safest i should go on the rear?

 

An experienced wheel and tire guy know what will safely fit on what because of doing it a thousand times. You are correct: some shops will not do installations that they believe are unsafe.

 

So basically i should stick to the stock 245's on the back?

 

I run 275/40s on the rear track wheels.

I run 275/35s on all four wheels for Solo II.

 

I have Touring 6 speed wheels. Can i run 265 or 255 on the back? If so what should the aspect ratio to keep it close to stock...40 or 45?

 

You want to exceed OEM width by 30mm without changing the OEM wheels? I am no tire expert, but I am sure that will not fly (or it will at highway speeds, if you want a pun )

David is right; ask a local tire shop (I don't mean Firestone) and let them be the best judge. I hope you reach a solution you'll be happy with.

As for the height, "keeping it close to stock" on stock wheels, would be the stock height itself. Be taller or shorter, and your VDC gnomes will get miffed. You don't want that, believe me.

 

Just find a more tuner friendly shop, they'll probably do it for you. If you back to the dealer they'll probably say no.

 

Well i got the idea on here...there are folks saying you can put 275's on the stock rims and thats the widest you can go.

 

Ive seen it done.

 

275/40's on the rear 8.5's? Is that for daily driving or just racing? I see you have the 275/35's for auto-x.

 

a 275/40 is ideally for a 9-11 inch wide wheel.
Although this is recommended a 275 on a 8.5 will work but may hinder handling due to a bulgy sidewall.

 

i had 275's on my stock 18's on my g...they fit but man it was a pain to get them on the first time

 

no point to try oversqueezing tires on smaller width wheel. you won't get to use the full 275 and its fugly with the buldge

 

Daily driving -- including on the little bit of snow and slush we get up here.

The tires may be a touch wide for the rears, but not by that much, 265s would probably be a bit better. The car looks really good with the 245s on the front (IMO the best size for the fronts).

 

um........what to say........

do you know how to read tire sizes? or can you just not say what you think in a understandable way. In order to keep the diameter of the rubber as close to the oem diameter and with a wider tire, you MUST change the ratio of sidewall to tire width.

a 275/45/18 would not fit well becuase your adding about 14 mm (124mm sidewall) to the RADIUS of the rubber. so you must adjust the side wall to match the oem sidewall of about 110 mm which would require a 275/40/18

adding 30 mm to the width can be done, but its at the limit. i run 255 on the oem 17's and will run 265 on my oem 18's. +20mm is common, and doesnt add points to my NASA tt class either....

how can we believe you about VDC being miffed? have you ridden in a Z with the vdc off? vdc screwed up?

not trying to attack ya, but had to correct the info out there

 

If you do this... be sure to carefully monitor your tire pressure and adjust accordingly. Mounting that large of a tire on that size wheel for daily driving can cause wicked tire wear if not inflated to the proper pressure. If it is too much, than the center of the tire will go bald very quickly and if it's too low... nasty tire wear on the side treads. And don't trust that the OEM recommended tire pressure will suffice, you'll probably need less.