aToxic, good selection on wheels. Are you still on the stock suspension? You mentioned no rubbing. Does that also include when you have people in the back?

 

I`m on Eibach (6383.140). Five ppl in car and 30 kilo in the trunk - no rubbing.
PS: neg rear camber -2.1

 

I find it really hard to believe that you do not rub whatsoever.

 

I think this guy need to post a pix so we can see that.

 

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Ok, so let me get this straight since I"ve heard different things from different people. So, my proposed plan for summer set up is 19x8.5 +35 up front and 19x9.5 +40 in the rear. If I'm running 245/40/19 in the front and 275/40/19 in the rear my rolling diameter would be exactly the same and I would have no issues with the VDC since the width of the wheel is of no concern?

 

Ok, think I may have answered my own question. Rolling diameter for my front tires would be off by less than a tenth of an inch by going with a 245/40/19. However, I looked at the rolling diameter for the same tire in a 275/40/19 and the diameter jumped up nearly an inch? I'm confused as to why it would do that...

 

Of course a 275/40 would have a greater diameter than a 245/40. You'd have to slim down to a 275/35 to match a 245/40

 

ya, I did some numbers on the Hankook Ventus V12, the 245/40/19 would be .09 off from the stock rolling diameter and the 275/35/19 would be off .17 from stock rolling diameter. That's seems like such a minimal difference to affect anything on the awd system. I read through the thread on myg37.com that is shared above and one of the vendors made a good point about numerous all wheel drive cars coming from the factory with staggered set ups with no issue whatsoever. Lefizzit, I think you're sportin 20's, what tire sizes are you running?

 

Fwiw your new tire sizes don't have to match the oem specs for your awd, all that accounts for is your speedo being accurate which is not a big deal. But, your front and rears must match (not exactly but minimal difference) for your awd to not be affected.

In my avatar I'm running 245/35/20 on a 20x8.5 +38 and 285/30/20 on a 20x10 +43 dropped on eibach here's a link with more pics I posted a while ago https://g35driver.com/forums/media-s...some-pics.html

 

Because:

40% of 275mm = 110 mm

40% of 245mm= 98mm

110mm - 98mm = 12 mm **

** but this is per sidewall, and you have two sidewall thicknesses included in the overall diameter so, by doubling it, it becomes 24mm difference which is pretty close to an inch (25.4 mm = 1").





That vendor also mentioned keeping the relative diameters between front and back tires the SAME. Just because a set of wheels has different widths on the front and back doesn't mean you can't minimize diameter differences to a negligible amount. I'm sure he intended to size them appropriately. Most likely, any AWD cars that come staggered from the factory have either had:
a) their AWD systems calibrated from the factory for any diameter differences
b) their tires sized accordingly so diameter differences are nil .
c) their system is engineered to be tolerant of diameter variations.

When you are considering diameters, I suggest your main concern be on how the front and rear compare to each other more than how they individually compare to the stock size, as you could potentially encounter a compounding effect otherwise.

 

^ so in my proposed summer set up i would be running 19x8.5 +35 and 19x9.5 +40. The rolling diameter difference would be .08 running a 245/40/19 and a 275/35/19 in the rear. Would you consider this to be ok? I would have to agree with you on some of the stock staggered set ups,I'm sure the car manufacturers accounted for this in some way.

 

245/40/19 = 26.7" diameter

275/35/19= 26.6 " diameter

difference = 0.1"

Now, considering the tires have 10/32" or .3125" tread thickness, which is three times the difference between your tires, that means you are essentially rolling on the equivalent of a set of tires that were the same size, but with tread on the rears worn down 1/3 more than the tread on the front. Does that make sense?

Plus, since you're diameter is dead on with the stock diameter, you'll have zero VDC or speedo issues there either. I'd say you nailed it.

 

whs, that setup is fine. Let us know how it goes.

 

For you guys with staggered setups on the X, how did it affect handling, specifically understeer? I'd like to get some wheels in the spring for my X, and had only considered non-staggered until reading this.

While I this staggered looks good, I'd rather not have any more understeer. Would a thicker rear sway bar (like the S model) negate any added understeer from a staggered setup?