Hi, I'm new to this whole rims and tires thing, but I'm wondering if you guys can help me. I have a G37S sedan with oem 18 x 7.5 front rims and 18 x 8.5 rear rims, if I want to upgrade to 19" rims what width and offsets would be the best for me since I have a sedan and what tire sizes should I get without it messing up the speedometer and gas mileage? Thanks for your time. I tried looking all this up on the forums but it just really confused me.

 

what size tires do you have on right now? in order to keep things kosher, you just need to keep the same diameter as you have now...so basically if your wheel is slightly bigger, you'll get a slightly smaller A/R tire.

 

I have 18 x 7.5 front rims with 225/50R18 tires and 18 x 8.5 rear rims with 245/45R18 tires....they are stock

 

225/40/19 and 245/35/19 would work...if the 19's are wider than the 18's you'd had to get a little wider if you didn't want to have a stretched look

 

Thanks but what about the width of the rim? I looked and it's hard to find rims that are 19x7.5, most aftermarket rims are 19x8.5 and 19x9.5 and up, which width would work best?....Would what have any effect on the speedometer and gas mileage? What about the ride itself?

 

245/40/19 will keep your speedometer calibrated.

 

That's the rear tires right? I know the g37s has staggered tires and do you know what width of the rims I should go with?

 

yes, that's the rear. if you want OEM specs, you can do 19x8.5 with 225/45/19 in the front and 19.9 in the rear with 245/40/19 in the rear without effecting your speedometer.

If you're not lowered, the ride shouldn't be too much different from the 18s. On normal roads, the 19s are pretty smooth. Only when you drive through bumps such as manholes, potholes, or any road imperfections, you get more of a harsher jolt. basically you have less tires to absorb the shock.

 

Thanks! What about 19x8.5 and 19x9.5 since I can't seem to find volks that are 19x9s for the rear wheels or 19x9.5 and 19x10? What would you suggest for those? Is it possible to get oem specs with those?

 

you can get into OEM spec with just about anything...if you PM Neal@TireRack or any of the tire vendors, they can tell you exactly what size tire will be best for you.

If you are looking at Volk, I would PM one of the Forged guys, they are the premier dealer of Volk wheels.

 

Thanks!!!

 

You can also simplify and just go w/ all of the same size on all 4 corners, plus it will help w/ tire life since you can really rotate all 4 tires. I had staggered on my 07 and like them all the same on my 09 w/ 245/35/20s.
Unless you really like the staggered look that is

 

yea I do like the staggered look

 

what tire size would I need for 19x9.5 and 19x10 rims? I tried pming the tire dealers but haven't got a response yet.

 

you want 9.5 for the front? seems rather aggressive.