I know there is the other threads about staggered tires and lowered suspension but I need help with this PLEASE, I bought coupe rims all 18 x 8, but tire sizes are front 225/45-18 amd rear 245/45-18. I went to get them installed thinking it would not be a problem because they are all the same diameter, but come to realize reading all these threads that it might not be a good idea after I installed them. I drove around for a while and no light came on. My questions are if its an issue will I get a light on my dash or am I ruining my awd and not knowing it? Should I keep them on or take them off? I did the tire calculator from one of these threads and it says 2.7% difference front to back. I thought I read 3% is the max difference you want with the awd system. Am I ok, does anyone have the same setup and have issues? I am just worried at this point, I have an 05 g35x. Thanks so much in advance!

 

3% is generally the max difference for ABS.

The AWD system has a smaller margin of error...1% or less. Too much of a difference will cause slip which will cause heat in the transfer case and excess wear.

Ideally you want 4 identical tires. How worn are your tires? Are they evenly worn? Can you get by replacing just two and have them close to wear so that the difference in diameter is minimal?

 

thanks, the front tires have 9/32 tread I believe and the rear have about 7/32. I havent noticed any difference in drive quality yet, will I get a light on the dash? Or am I just wearing it out and not knowing it

 

Well my awd light just started flashing, what can I do until I get them off? Pull the awd fuse in the meantime?

 

Yes, pull the fuse from now. That will prevent the AWD system from trying to lock up the center diff and having to fight the different diameters of the front and rear wheels. Not ideal...but it's probably less damaging than doing nothing.

Your car is basically RWD now with the front drivetrain along for the ride. You'll want to address the tire situation soon though.

 

Thanks so much bro, discount tire said they have four take off tires like new 500 miles continental tires 235 40 r18 they could sell me for 450 or the door, what do you think?

 

I personally would never buy take offs but it is a few hundred off. Up to you and your judgement.

 

Yeah I was thinking about it, they say 500 miles on them and they will come with discount tires warranty. I am going to see if I can get them any cheaper I guess.

 

Actually the tires are 245/45 r18. Would that even work with the x all around?

 

^Don't see why not.

I would always treat AWD like 4WD. Certainly possible to have a lot of stress on the transfer case if the overall diameter between the front and rear tires don't match. Like Mustang said, always run the same size tires.

 

thanks, I am now trying to figure out if 245 in front will look too big or should I just try and find 225 all around? I really want to get this resolved tomorrow amd don't know what to do. Anyone run 245 all around and like it?

 

Well I picked up 245-45 r18 tires all around and do loke the look. 225 just seemed kind of small, maybe just comparing the two. I took a pic of one side with 225 and the other side 245. Am now thinking of not lowering it with 350z springs, so I might sell those. What do you guys think? Trying to recover some of my losses at this point. Also will be selling staggered set of 225/45 and 245/45 if anyone is iinterested shoot me an offer. I am in chicago.



These are 245/45





These are 225/45

 

Different sidewall heights

225/45 = 50.6mm sidewall

245/45 = 55.1mm sidewall.

So the 245's will be a little taller.

OEM tire size is 215/55/17 which is 26.3" in OD.

245/45/18 is 26.7"
225/45/18 is 26.0"

So 245 is a little taller sidewall, but not far off OEM. 225 would be a little closer to OEM. Do you live where it snows? 225 would be a little better for snow.


But as long as all 4 wheels match in OD, you should be fine. Speedo might be a little bit off as well, so try and check it with a GPS device

 

Thanks for the info. Think I might stick with the 245 and bot lower it for the time being. They are summer tires so probably will switch to the stock 17s in winter I guess.