Hi there,

my 2008 G35, touring package came with 2 front tires are 225/50-18, and two rear tires are 245/45-18. Since tires are not same for both, so they are can not be rotated and it's a reason why these tire life so short. I just spent more than 1100 and put on them 17,000 miles now time to replace new set. Killing me!!!. Question is can I use all four tires the same size? if so which size i should base on rear or front? any down side for all tires to be the same size on this perticular vehicle ?

thks

 

Hey man,

I'm guessing that nobody wants to offer an opinion saying one way or the other because putting tires on the car different than what Infiniti specified can be very dangerous in the way of handling. It was designed to have the staggered set up, and it should stay that way. The best you could do to increase your tire wear lifespan is to have the car specifically aligned for highway travel. You may need to plead your case to the mechanics, and they will likely tell you it won't do much good, (It might not do much good!) but it could help depending on how your alignment is right now.

The other thing is to buy tires that have a very high treadwear rating.

 

If they are asymmetric non-directional, you can rotate left-right without mounting/dismounting. If they are directional, you can have it mounted/dismounted, when flipping l-r.

You can use a square set-up, but generally the rears are meant to grip more than the front to help alleviate oversteer -- a trait of RWD vehicles.

For tame daily driving, it won't matter much if you choose the 225 or 245 all around. If anything the 225's will probably be cushier and edge slightly with mpg.

However, take note that your wheels are of different widths, so they are still technically running staggered, with those tires mounted on the wider wheel being slightly wider. Tirerack has a general guideline on how much tires of similar widths end up widening when mounted on different width wheels.

Your best bet would be to just go ahead and purchase a new set altogether.

Possibly dangerous, but i've run a square set-up on my RWD without any real issues.

 

First off, you should note that you have different sized wheels. The fronts are 7.5" wide and the rears are 8.5". Your front size tires will not fit properly (and as intended) on the rears and your rear sized tires will not fit properly (and as intended) on the fronts. I wouldn't recommend just installing the rear size tire on the front rims, as they're not intended for such a narrow rim (You'd get rolly-polly muffin tops). Likewise, installing fronts on the rear rims would require a bit of stretching (often done for looks lately, but definitely NOT the safest either). Either can be done, but they are both significant compromises. This then poses the option of getting an additional pair of either front or rear rims to complete a non-staggered set. If I had to do so, I'd go with all rears.

If you put rear wheel/tires on the front, you'll need to remove the stud that's inserted in the front hub to prevent accidentally putting rears on the front. As far as handling goes (assuming rears on front), you'll get better turn-in for sure, but you'll also pick up some over-steer (ie. tail happiness). These attributes are much more likely to be experienced by driving more aggressively near the car's limits, so if that's not your style, then you may never know the difference. At the very least though, you should know what your car's tendencies will be.

If you went the other route and installed front wheel and tires on all fours, you'll most likely loose some grip in the turns and pick up more under-steer. Again, this would present mostly as you approached handling limits.

To be honest, a lot of people have considered what your trying to accomplish, but then backed off when they considered the ultimate costs to do it properly vs. extra cost of poorer tread life. Food for thought.


EDIT: Mike, you beat me to it. I gotta learn to type faster lol.