Ok, so this may sound like a stupid question, but im going to ask it anyway. I am almost at that point where i need to replace the rear tires on my x. I was curious to see if anyone has ran any size tires wider than the stock 225/55? Again, im not a tire guru so i have no clue if this is even possible, just wondering if i have any options as far as sizes? Also, since i have 225/55 on the fronts i would need to keep the same size sidewall(55 series). Any input would be appreciated!

 

You just need to keep the same outside diameter so you can go wider in the rear, you just won't be able to do a full tire rotation anymore. You should be able to go up to 245 in the back w/ that rim width. The 55 on the sidewall is the percentage of the sidewall to the width of the tire, it's not a fixed value. A 245/55 would have a different diameter than a 225/55 for example. The wider the tire the smaller the sidewall % has to be, to match your fronts a 245/50/17 will match the diameter. Here's a calculator if you want to check other sizes
http://www.1010tires.com/tiresizecalculator.asp

When it comes time to replace the fronts you can go 245 up there too, both my Gs ran 245 on all 4 corners and it works well IME.

 

NO ! dont i did that and lost my handling HORRIBLE
If im still on stock wheels next time i get new tires, Im going with stock sizes again

 

^ not sure what your experiencing but thinner sidewalls and thicker width helps better your traction and help sharpen the handling as long as you get decent tires that dont have soft sidewalls. I have 245/35/20 front and 285/30 rear and the handling is great and MUCH better than stock.

 

^+1 same exact specs

 

You possibly know this already but it should also be mentioned that for AWD it is recommended that all 4 tires be replaced at the same time. I won't ramble on, there is lots of info in the owners manual.
Assuming you are replacing with the same brand of tire and outer circumference, be sure that the tread depth difference between the worn front tires and the new rear tires, is < 3/32".
No sense in putting your AWD sys/differential at risk. If anything happens to it the first thing that Infiniti will check is your tires.
http://www.tirerack.com/tires/tirete....jsp?techid=18

 

Although many people here make valid points, even the exact same tire from one to another will have slight differences because of manufacturing tolerances. I also believe that our AWD system is designed to tolerate up to 10% difference in rolling speeds therefore if you match the tires to withing 10% of circumference you should be OK.

Having said that a wider tire will give you better grip in the summer, however the grip will decrease in wet conditions. I don't know if you live in a snow belt and if you do your grip in the snow will be significantly decreased because of wider tires. Another negative of going with wider tires is that your MPG will slightly decrease because of the increased friction between the tires and the road.

http://www.tirerack.com/tires/tirete...urrentpage=136

There is also an article from car and driver where they compare different tire sizes and measure the results in a controlled environment. At the end of the day it is your decision, but my personal opinion is to stay with the stock size tire.

 

Thanks for all the input guys. Thinking about what everyone has posted, along with that helpful article TomeK posted, im going to stay with the stock size. Also, just read that car and driver article and deffinitely gave me a better understanding of tire sizes and pros and cons of a wider tire. Thank you again for your help and advice.

 

you had bigger tires in the front? how did that work out?

 

Ok, bringing this thread back lol. So i have yet to pick up new rear tires but i am leading towards continental DWS. The problem is the closest size they come in is 235/55/17. You think i will have any problems with running these in the rear and 225/55 in the front?

 

The 235s are going to be about 4/10ths of an inch taller and is about 1.5% difference compared to stock, not sure if this will cause AWD issues, you really want to run identical diameters w/ AWD from what I've heard. Here's a handy tire calculator, it may help you find a more similar diameter.
http://www.1010tires.com/tiresizecalculator.asp

 

I am going to slap some Michelins pilots on my x before the ohio winter season sets in. Yes they are expensive, but ive had great luck with Michelins and there is a $70 for 4 rebate.

http://www.michelin-rebates.com/

 

IDK where but I heard they were discontinuing the DWS which might be why they're out of certain sizes. Nevertheless, my dad got DWS tires on his M35 and really likes them.

 

You might want to do some checking on recent posts here. In the past few months, I have seen at least a few people on here complaining about the feel of their new Continental tires. Might want to make sure you aren't getting the same ones.

 

Deffinitely will, thanks for the heads up