Staggered Wheels on the M35x (awd) model

[a.blanco0905]

i just took my staggered rims off today!!! i had them on for 2 days and they had the awd light blinking like krazy, slip and vdc off lights too. the ride was nice though. but not worth hurting my M!

i strongly suggest not putting staggered rims on the m35x/m45x! even if the tires are the exact same and they are made for ur car. its just not a good fit for these cars.

Your rear tires and fronts different sizes??? That will actually change the rolling diameter of the wheels from the front to the rear, no good for AWD.

Werent you trying to trade BlueM35 these wheels just yesterday?

[SteveTheTech]

i just took my staggered rims off today!!! i had them on for 2 days and they had the awd light blinking like krazy, slip and vdc off lights too. the ride was nice though. but not worth hurting my M!

i strongly suggest not putting staggered rims on the m35x/m45x! even if the tires are the exact same and they are made for ur car. its just not a good fit for these cars.

You did the right thing in pulling them asap. The car has the ability to detect a variance in diameter of 2mm on any other the wheels. There is a certain margin of error but that quote pretty much seals the debate.


The Audi awd system is nothing like the system in the M.
http://en.wikipedia.org/wiki/Quattro_(f ... ve_system)
http://en.wikipedia.org/wiki/ATTESA-ETS

Wheel speed and diameter and much more critical in the M.

[szh]

He says that as long as the wheels have the same diameter it will not hurt neither the diffs or the AWD system... i.e. do not put a 20" wheel in the rear and 19" in the front on any AWD system but you can have 20" in the rear and in the front even if they're not the same width.

No. Not the same thing. Plus, the Audi and Nissan systems are not comparable.

If you put different width wheels on a car, even with the same diameter wheel, you will have to get different tire sizes (with differing aspect ratios) to try and get the same rolling diameter.

And you will fail to make it match well enough for the Infiniti system! The reason is that static and rolling diameters for different sized tires are quite different.

So, what might measure "close enough" on a lift, may well have slightly different rolling diameters when the car is at speed ... for an extreme example, ever see what happen to the rear wheels of a nitro dragster? Just the act of applying torque and spin causes these soft tires to expand in diameter by a lot.

Of course, I am not trying to compare that effect to what happens here, but just pointing out that this is not as simple you might think!

And, the results of potentially damaging the ATTESA sysem on your Infiniti X models in this manner, will not be covered under warranty - the manuals are explicitly clear about the requirement. Please see my extracts earlier in this thread!

Z

[gatiman]

I have read many posts on this topic before making my decision and agree "that this is not as simple you might think!"..it's all in the math.
That's why after reading this post, I am concerned.

I have a 2008 M45x and recently purchased Vossen VVS-085 wheels and Michelin PS2 tires in a staggered configuration. I am an engineer and worked with my local high performance wheel/tire owner who states this setup is "perfect" for the AWD M45x. They do staggered set-ups on Bentley GTs, Audi Quattro cars, Porsche 911 Turbos, Lamborghini Gallardo, etc. all day long here in Atlanta, and the only ones that do a 130 mph on the car wheel balance.

I have been driving a while now on them, at speeds over 80 for long periods, in 70 degree weather with no "warning lights" going on, no rubbing and handling issues.
I have stock suspension with no plans to deviate, why create problems?

Here is my setup compared to stock:

Stock Wheels 18 x 8 (ALL)
Stock Tires 245/45/R18

Sidewall: 4.3"
Radius 13.3"
Diameter 26.7"
Circumference: 83.8"
Revs/Mile 756

Vossen VVS085 20 x 9 os +38 FRONT
Michelin PS2 245/35/ZR20

Sidewall: 3.4"
Radius 13.4"
Diameter 26.8"
Circumference: 84"
Revs/Mile 754

Vossen VVS085 20 x 10.5 os +45 REAR
Michelin PS2 285/30/ZR20

Sidewall: 3.4"
Radius 13.4"
Diameter 26.7"
Circumference: 84"
Revs/Mile 754

By these calculations the speedometer reading is slow by .2% meaning the speedometer is reading 60 mph while the car is actually traveling 60.1 mph.
In terms of Revs/mile is 99.75% accurate as compared to the stock specs.
My New Front and Rear setup is matched.

I am really curious, So my question is "Why would this affect the ATTESA system or ruin differentials?"

[The00Dustin]

According to SteveTheTech's quote saying it can detect a difference of 2mm, I'd think you'd be fine until/unless the fronts wearing quicker brought their diameter down to 2mm less than the rears wearing had brought them down to. That said, I'm no expert, and I don't imagine you'll get anyone in the know here to tell you that your setup would probably be fine because they don't like the risk. As for why it could damage it, someone else will have to let you know, but presumably there is some linkage with very little tolerance and an extended and significant difference between the spin speed of any two wheels could cause premature wear. This begs the question, how do these compare to your spare's diameter? This only matters if you would actually use a spare, but personally, I can't imagine getting towed instead of putting on a spare (primarily because of the time spent waiting for service).