my AWD light on my 05 sedan has a slow blink when i got over 40mph and punched it. I'm on 350z track wheels, staggered setup. The wheels came with 235/40/18 and 265/40/18. So i had to choose whichever setup works the best for me. obviously the best choice was to run same profile all around and i will when i buy a NEW set either next season or the one after that. i found 265/40/18 was very close to the 215/55/17 i had stock, obvious choice was to keep that. I ran just rears for 2 weeks no problems. Now i found 225/45/18 was the closest i can run other then running 265 in the front.

I put those wheels on and BOOM the light comes on. So i read up in the service manual page TF-43, it clearly states what i'm doing with diffrent profile tires BUT it doesn't say what the damages will be done, I know most systems run a fail-safe mode where if a fault is detect, it will just disable the system, this is what i'm leaning towards. That way no damages will be done.

Something the peaked my interest tho, on the FSM it showed 0-4mm of clearance i wonder if one could increase that amount with the help of consult.

 

It's not the staggered setup itself that's causing the problem, it's having fronts and rears with different outside diameters that's causing it. There are others on here who've run a similar setup, mostly for summer driving, and they've pulled the fuse on the AWD and haven't had any problems. It appears you won't damage the system, but that doesn't mean the system is going to like it, i.e. the AWD blink.

BTW, 235/45-18 is actually a better fit for your fronts. I know Tire Rack and other sites show the 225/45's as stock for the 18's, but it doesn't match the stock outside diameter.

215/55-17 = 26.3" (stock)
225/45-18 = 25.9" (your future F)
235/40-18 = 25.4" (your current F)
235/45-18 = 26.3" (my recommended F for you)
245/40-18 = 25.8"
245/45-18 = 26.7" (my future F and R)
255/40-18 = 26.1" (will be VERY stretched on an 8" wheel)
265/40-18 = 26.3"-26.6" (your current R, most are 26.3, but Bridgestones are 26.6)
* All diameters are about average for that size, but check the individual tires as they can vary by .1"-.4" with certain manufacturers.

Those fronts are just too small for an AWD. You really should keep both setups within 2-3% of stock for odo/speedo accuracy and VDC performance. You should also keep each setup within 2-3% of each other on the AWD system or it won't like it. Your setup is off on both, fronts are 7% below stock, and 7% different than your rears. The 225/265 F/R setup would meet both these criteria. just barely (F's 3% off on both), but the 235/45 - 265/40 is even better (both match stock).

 

aw, crap i think i got my tire sizes mixed around. 235/45 was what i wanted to be near matching.

blah....oh well these will most likely be on for 2 summers. Do you think the AWD is disable when it blinking?

I noticed a huge chug when the car downshifted into 2nd, like if you downshift into 2nd without rev-matching feel in a manual. That was something new.

well as much as i like the 265 in the rear i think i'm going to drop down a size or go same all around. according to your list, 235/45/18 all around or maybe i can run something staggered that is slightly smaller then 265, its a little beyond flush...plus tire prices for 265 are a steep.

back on topic, so now that the car and the AWD system knows that i'm running mis-matched tires profiles what does it do exactly? does it shut down the AWD if slip is detected or some type of limp/fail safe mode? Or does it act normally telling me that my tires are wrong. Yea i know AWD isn't a constant on, so in theory not having AWD will make no difference. I barely need it in the summer other then heavy rain anyways..

 

Don't know, check the manual.

How wide are the rear wheels? I assume you have 18x8's in the front. If you go smaller than 265, you'll probably have to change your profile size from 40 to 45 if you want to stay as close as possible to 26.3". At that point, you might as well run the same tires (235/45 or 245/45) front and back.

The thing to do if you want a staggered setup is make sure the tires are close to matching in diameter, and somewhere between -3% and +3% of stock, which is approximately 25.9" to 26.7". That means looking specifically at the sizes of the tires you want to purchase. Like I said, different manufacturers can have slightly different sizes. And not all 265's are expensive. Here are some matches that will still let you be staggered. All the tires are under $200 each, and most much less than that. If you want a more expensive tire, than you'll have to do this research on your own. It's not difficult. I used Tire Rack and TireDeals4Less.com to get specs/prices.

Staggered matches F|R Make (Diam.)
225/45-18 | 255/40-18 General Exclaim UHP's (26.0"), Toyo Proxes 1TR (25.9"), Bridgestone Potenzas (most models) (26.0"), Continental ExtremeContact (26.0")
235/45-18 | 265/40-18 General Exclaim UHP (26.3")
245/45-18 | 265/40-18 Bridgestone Potenzas (26.6") (some models, double check if you go this route)
245/45-18 | 275/40-18 General Exclaim UHP, Continental ExtremeContact, Hankook Vestus, Kumho (multiple models), all about 26.7"

I don't recommend the 245/275 matches. If your 265's aren't flush, the 275's will be worse (it's the low offset from those Z wheels causing it). But the 225/255 match looks pretty good and will tuck your rears a little more.

 

actually u might hurt the awd system that way. ive had an sti and evo before and they're both awd, both cars required tires (width,diameter,etc) to be close as possible because its needs to run symetrical and nsync together for maximum performance and benifits from the awd system, so maybe thats whats going on with yours.

 

did you really just tell us that you put different diameter tires on AWD system and oh surprise your AWD system is complaining?! well, who didn't see that one coming?

 

FSM doesn't state if the system is disabled or not. I'm assuming it is on but i prefer it to be off.

F wheels are 8.0 and rears are 8.5



actually i thought it would be close call since i did attempt to get it near each other. It might of not been the closest attempt i could of made.

 

Oh, that changes some things. 8.5" wheels aren't wide enough for 265 or 275 series tires, and are the minumum width for 255 series tires. I figured you had 9's or 10's in the rear.

 

i like the 235/265 combo, but i dont think there is a 255 combo that is as close.

the 265 on 8.5 isn't like crazy. If anything it would just be the SLIGHTEST strech, most sites recommend 255 being the largest but some show 265 as well. but i'm most likely looking to ditch the staggered tires as much as i love the look.

 

Close to what? Stock? You're right, there isn't. But 26.0" is well within the 3% margin, and will fit on your wheels. The fitment range for every 255 I've seen is 8.5"-10".

Not sure where you're seeing that a 265 of any kind will fit on an 8.5. Everything I've seen shows a 265's wheel size fitment is 9"-10.5" across multiple tire manufacturers (BFG, Bridgestone, Continental, General, Goodyear, Michelin, Pirelli, Sumitomo, Yokohama). Just because 1 source for probably 1 tire says it will fit doesn't negate all these other manufacturers that say it won't. Oh wait, I did find 1 source that shows a 265 fitting on an 8.5" wheel. It's a BF Goodrich T/A Drag Radial, but it's outside diameter is just 25.6", which is well below the 26.3" of all the other 265's I've seen, so you'd have to run those 225/40's with it to keep the tires within 3% of each other. Of course, it's also a discontinued tire that doesn't show up on BFG's website, so we'll have to take sfxperformance.com's word for it.

The problem isn't getting the tire on the wheel, it's that it will change the geometry of the tire beyond it's original design. It will put alot of extra strain on the bead and sidewall, and will distort the contact patch. My guess is you'll see wear problems, deflation problems, and a decrease in cornering capability (the tire will "roll over" more in turns). It will wear down the center faster when fully inflated, and you'll get cupping when it's underinflated. It may also negate any warranty the tire has. Anticipate about a 50% drop in tire life.

The 225/45 - 255/40 is a better option. It's not "crazy" to put a 265 on there, but it's a lot closer to "stupid" than it is to "smart". Your money, your car. I've said my piece.

 

thanks buckeye for the break down on tires. i'll make up my mind next summer on what to run.

I think i'm going to run what i have now, Tires are off but not extremely off. I know the system wont like it and I dont mind the AWD blinking. Like all other members i seriously care if there is damage being DONE. From what i read pulling the Fuse will not completely disable the AWD system. I'm just going to roll like this for the summer and see there are any DEALS come end of summer.

 

My opinion is that damage is being done. A summer of constant slip between the clutches is bound to create significant wear.

 

+1, glad it's not my car.

 

looking at this thread, these guys posted up their tire sizes and they are WAY more off then what mines are

https://g35driver.com/forums/g35-sed...us-fuse-2.html

i'm looking to pick up a pair for 235/45 now =)

 

+100000