I got a good deal on some Falkens for my G35x about a month ago and now am having second thoughts due to 'warnings' I keep reading on various sites about differential damage due to circumfrential difference, I'm running 235\35\19 front and 245\35\19 back so a very slight stagger. By my calculations the fronts have a circumference of 2033 mm while the backs have a circumference of 2055 mm (calculated) which is 22 mm diference (~1.1%), the radius differs by 3.5 mm (323.55 mm versus 327.05 mm) again about 1.1%. Falken indicates the revs per mile to be 815 on the slightly smaller fronts and 805 on the slightly larger backs (a 1.25% difference). So far the car has been operating great on this set up with no issues (around 1200 km on them). A manual check of tire diameter (cold) just now indicated exactly 635 mm all round (I keep the fronts inflated to 37 psi and the backs at 33 psi so maybe that helps raise the front diameter).
Any opinions? ... sell them, keep them, your crazy the differential will fall apart, no big deal, etc... Regardless I do have a concern the dealer may not be forthcoming on any warranty work involving transmission\ differential problems should they happen, but I could always through on the stock tires before going in if that happened as I still have them. Constructive opinions\ personal experience are very welcome. Thanks.

 

i don't believe it should be an issue on the x since its not a regular 4WD xfer case but i still wouldn't take a chance. that being said i'm not an expert so i'll wait for someone to chime in who knows better to back me up.

i do remember though that on strictly 4WD cars this is where the issue you speak of would arise.

 

I talked to my dealer's service manager, 2 of my personal mechanics, and my tire shop guy, all said not to do it. The fact that the car comes with same size all around is a good indication too.

That being said, quite a few guys here are running staggered on the X and say they have no issues.

I wasn't brave enough to go against all the advice I got, so I stuck to the same size all around.

From what I was told about staggering is that the car thinks the front and rear wheels are going at different speeds, thus it "thinks" the fronts are always slipping, and thus the AWD system is working harder, all the time, to divert power accordingly and balance it. That's the idea anyways.

I don't think your 1.25% difference is an issue...
From my research, pretty much every newer AWD system allows a minimum 3 to 5% tolerance in front to rear diameter differential, apparently, to allow for spare tire use, different tread wear, and different tire manufacturer, etc.

On that note, I don't think you'll have any issues of damage to your diff.

 

I'm running staggered setup with no problem

20x8.5 245/35/20 +38
20x10 285/30/20 +43

How wide are your 19's that you're only running 235/245?

edit: as a side note it doesn't matter how wide your wheels are as long as you match the diameter/circumference by choosing the right profile. Even though I'm running 285 in the back, my wheel specs are closer in size than your wheel specs

 

Thanks for the feedback guys. I had read up to 5% on some sites but on others it was 1% maximum but I think that was for a Subaru. lefizzet you have an excellent almost perfect match there whereas mine is not quite as good. Have you ever had any issues with the dealership and warranty?

 

[QUOTE=lefizzet;5330333]I'm running staggered setup with no problem

20x8.5 245/35/20 +38
20x10 285/30/20 +43

How wide are your 19's that you're only running 235/245?

^I beleive the fronts are 8.5 and the backs are 9

 

staggered X here too 245/40 on 9inch 275/35 on 10 inch rear. no problems...

 

Running a slight stagger with 245 35 20 and 255 35 20. No problems!

 

iiiiiekoiiiii, terfer. How long (how many kilometres\miles) do you have on the car using a staggered set up? Any complaints from the dealer? Thanks.

 

3yrs. 9sets of staggered rims and 40k + 2inch drop on stock suspension.

 

What's the point of staggering on an X and is the benefit worth the risk, or any risk? I'm not arguing, just curious.

 

Not an issue. Spoke to the Service Mgr at the dealership specifically about this. The Altessa system allows for approx .1-.3" of OD flex front to rear. Just make sure the OD of the tires are equal or very similar. If not exactly equal, run the larger OD tires up front so the transfer case doesnt sense any slipping

My set up
225/40/19 F = 26.1" OD
255/35/19 R = 26.0" OD

not an issue at all.

 

Just out of curiosity, wouldn't a larger front tire = less Rev's Per Mile ultimately making the rear wheels turn faster than the fronts and causing the AWD system to sense slipping? No disrespect to your logic (as I don't know what works) but it seems like you would want to do the opposite. A little bigger in the rear seems like it would be better for a RWD based AWD system.

 

I've been thinking of doing some 19" G37 coupe wheels on my X, and have been worried about the staggered setup myself.

Someone help me out.....

The Nissan GTR has a:
ATTESA E-TS® All-Wheel Drive (AWD) with patented independent rear-mounted transaxle integrating transmission, differential and AWD transfer case
Except for the rear mounted transaxle, it sounds like it is similar to the same setup that we have on our G35X's.

The factory GTR tires are:
Front- 255/40R20 with an overall diameter of 27.9"
Rear- 285/35R20 with an overall diameter of 28"

Factory G37 Coupe 19" tires are:
Front- 225/45R19 with an overall diameter of 26.9"
Rear- 245/40R19 with an overall diameter of 26.8"

If this works on the GTR at speeds of 180mph, is it safe to say that the staggered coupe wheels will work on ours? They have the same amount of difference though it is in the reverse order. According to some on this thread, the larger tires on front is desired.

 

Good point big john. If it works for the GT-R then why not the G35x.