I just bought 06 factory rims for my 05. They are 18 x 8 and 18x8.5. I need to buy new tires for them so I thougt it might be good to go wider. I like the side wall of the tires now they are 225/45/18 and 245/45/18. So If
I up the first # and keep the second # the same 45 will the side be the same height as now? I figured I might be able to get 235 or 245 front and 255 or 265 in rear. I want them to look good so if I'm on the wrong track let me know.

 

the tires you want are 245/40 for the front and 275/40 for the rear in order to keep basically the same diameter.

 

To find equivalent tire sizes use this calculator: http://www.dakota-truck.net/TIRECALC/tirecalc.html.

 

Can you fit a 275mm tire on a 8.5" rim?

 

Yes , but its to narrow of a wheel 265/40 would be better. I just dont know how many brands have good ones available. A 235/40 255/40 combo wouldnt be bad.

 

Manufacturers rec'mnd a 9-11" wheel for a 275 tire.

 

Edit.

 

Nice, but he is asking about 8" and 8.5" wheels. The 8.5" wheel shouldn't have a tire larger than a 265 MAX, and preferably a 245 or 255.

 

What do you guys think of a 235/40 front and a 255/45 tire out back on 06 rims? From stock the sidewall on the front drops .28 inch and on the back increases by only .17 inch. I am thinking of doing these sizes in the Falken 452 tire.

 

I would go 245/40 and 255/45

 

Thanks, that seems like a good combo. Will there be any issues with 245/40 in the front?

 

I'm running the 275R/245F combo on my '06. Definitely way better than stock, but that's all I have to compare it to right now. I wanted to go with 265s in the back, but couldn't find much of anything in that size. The 275 is just a little bit big.

 

Did you use the calculator that I posted or is this just another What size fits? waste of time?

 

The difference is 41.5mm. That's a big difference.

 

Well I guess you answered that question loud and clear.