I have a '10 G37S and I have to get new tires very soon. Is it a big problem to change the aspect ratio or is it just a visual change? I hate how my car doesn't have the same all around. I also want the front tire a little bit bigger. I want to put 235/45 up front and keep the rear at 245/45. No problems here?

 

The tires aren't the same size because your OEM wheels have a 1" stagger... 7.5" front, 8.5" rear. It's that difference which makes the 225/50 tires properly matched with the 245/45 tires, respectively.

I'm only putting that out there on the chance you didn't know. I once has a conversation with an Infiniti Service Manager who didn't believe me. That was awkward.

 

You could run 235/45 front since you have a RWD, the 7.5" is about the narrowest wheel for that tire size, it will be about a 1/2" taller than your 225/50 though.

Like Rochester mentioned, you have 1" wider wheels in back. When you take off your wheels you'll notice there's an extra bolt in front that is there to keep from accidentally swapping your rear wheels to your front.

(IIRC it's in front, could be in back though )

 

blnewt's right, definitely the front. I bought a set of blizzaks this weekend and was watching as the tire tech tried to install the rear wheel on the front. He was confused as hell, which was awesome to watch...I let him down gently.

 

I get I have I have a staggered setup. I'm just asking if the smaller aspect ratio is ok? I want the tire profile to be the same. No problems?

 

Some of those service managers are idiots. I had one argue that it was "normal" for my car's battery to be dead after 2 days of the car sitting. Another told me I don't know what im talking about when i brought the car in for a TSB which they refused to do.

No, you should be fine

 

The tire profile won't be the same, as you go wider you have to go down in sidewall series to keep the diameters similar. The 235 is a between size vs. the OEM 225/50 & 245/45, if they made a 235/47.5 then you'd have the same profile but the 235/45 will be about a 1/2" taller than your current 225/50s and about a 3/8" shorter than your 245/45s

 

I thought that bolt was used to help remove the brake rotors. I did my front brakes recently and noticed that bolt. It was like a 10 or 12mm with a plastic sleeve around it.

You remove the bolt and take off the plastic sleeve than reinsert the bolt into the threaded hole and screw it in with a impact. It backs the rotor off the hub for easy removal.

Maybe it serves multiple purposes lol

 

Several websites have calculators for comparing different tire sizes, such as:

http://www.discounttire.com/en/learn...ize-calculator

This may help you select and match tires that will suit your particular needs.