I purchased a set of 19x8 Rays wheels for my 08 g35xS sedan. I want to know what is the largest/widest tire i can put on those? I am running stock suspension and will not change. I am thinking 225/45/19 but can i go 245/45/19?

245/40/19 would be the ideal setup for your 8" wide rims. They would be almost the same outside diameter of the original 245/45/18 tires.

the original 18s are 225/50/18, arent they? I want comfort on the 19's so i want as much sidewall as possible. From the tire calculator, it looked like 225/50/18 and 225/45/19 were very similar.

I'm running the suggested 245-40-19 and I didn't notice much loss in comfort at all.
I'm very happy with the setup, as the car remains very comfortable (even wife approved) and I kept a very accurate speedo at the same time.

hmmmm.....are you on the stock suspension? do you have some pics of your car?

ive done of the 40 series before on my other cars and the comfort was not that great. i dont know...

I was referring to the above quote where you asked if you could run 245/45/19, that size is way out from your stock od, but the 245/40/19 would be almost perfect. Plug them into your tire calculator and compare the size I suggested to 225/50/18, they are almost identical.
245/40/19 is right for your 19/8 rims. It would be much better than 225/45/19 on the 8" rims

I do agree if you want a softer ride you will get it with the 225/45/19 over the wider lower profile tires and they are also the right outside diameter. You do not have as much choice in that size tire either.

yes and at this point in my life, comfort > looking/handling. The Nitto Invo is available in 225/45/19. id get the yoko s.drive if i were to get the 245/40/19.

Sounds good .
Make sure to post up some pics when you get your new shoes on.

I think manufacturer recommends 225/40s. I have the staggered Rays, and they recommend 225/40 and 245/40.

If you have the 8" all around I would recommend 225/45. They are closer to our stock tire size and just look better in the wheelwell. My fronts looked SO small before I lowered it. Check the tires section here, as this is a very hot topic in that area. Some people say going to the 245s on the 8" tire is fine, others disagree. I personally think it would be fine.

There was a guy a while back that did 245/45s on the Rays without lowering his car and it actually filled the gap quite well...looked good.

Bat, many people who don't understand tire sizes thinking simply a lower aspect ration (the middle number - 40 or 45) mean a shorter side wall. While that's true it is actually not that simple. It's an aspect ratio, a percentage of the tires width. For example: 225 (mm of width) 45 (% of the tires width - 225 divided by 45) 19 (inches of the tires inner diameter). Knowing this you can do some math. You'll see a 225/45/19 has approximated the same side wall height as a 245/40/19, but the 245 is wider. Your car may ride slightly different with 245/40/19 as opposed to the narrower tire, the side will not actually shorter.

^^^ +1 Well put EWG35

Stock suspension (for now) on 245/40/19's (Falken FK452's)

Who's GT-R is that in the back ground? Please don't tell me you own a G35 and a GT-R. That is just being cruel to the rest of us.

wow....nice rims!!!

I am going to do the same thing soon, but will not be lowering it.....still debating on 18 or 19s.

BTW...nice GTR in the background!