Tire Size on Stock 18's
 

Yes, I've done searches, but most people have up sized their tire sizes from the stock 18" to +19".

Since I bought my G35 Coupe Sport Package used, the tires are worn out. I'll be keeping the stock 18" rim. The stock Pilots are 225/45R18 and 245/45R18 respectively for front and rear. Can I put 40 aspect ratio tires on these? Like 225/40R18 and 245/40R18? They seem to be easier to find.

Also, what are you opinions about mixing brands between front and rear tires?

Finally, it's probably retarded, but you can't have 225/45R18 and 245/40R18's right? Don't ask why.

http://www.discounttiredirect.com/di...pager.offset=0 245/45 18

http://www.discounttiredirect.com/di...25&ar=45&rd=18 225/45 18

Not very hard to find at all... You want hard to find (cheap)? Try my rear tire...

As far as the question, I don't see why lowering the aspect ratio would be a problem. Not sure though.

Why cant you? it can be done, but the rears are about inch shorter and speedometer will read faster than you are going (2~3mph)

most people? Hey man I am still riding on 17"

You'll want to consider the appearance of any different sized tires and the wheel well gap that will leave. As well a major consideration is the affect on the ABS and VDC. I think it is acceptable to have up to 2% difference in wheel circumference without problems but I suggest checking this with your dealer.
Why would you want to mix brands? It can be done of course but will change the handling and braking dynamics and not in a positive way.
I believe you can go with 245 40 18 fronts and 265 40 18 on the rear which will closely match the OEM tire height and should be okay with the 8" rims. Again I suggest checking with a good tire shop or the tire rack or discount tire web sites on this.
Good luck.

may be your traction control will mess up, wheel/tire diameter should not change change tire hiegh you should change your rims i think

Do you guysknow if the offset is the same or different for Z stock rims compared to the G35 coupe 18 rims?

I've heard people running 245/40R18's on the front and 245/45R18's on the rear.. as this helps reduce understeer. Anyone have any experience and/or comments on that?

That would be a good way to go as it's the only other way (besides oem sizes) to maintain the stock diameters.