Darookie27

Well, not exactly....BUT that as close as you'll ever get at a .02 Difference
without using the same 4 tires all the way around. (nice combo By the way)
Front: 19x8.5 235/35/19 = 25.476
Rear: 19x10 275/30/19 = 25.496

I would like to stick to 18's , this give me more sidewall height options - 45\40(more cushion) The roads here in Southeastern PA are Horrible, One nice pothole, and there goes the tire, rim, etc...

almacruel

Hahah you caught me... The website I used wasn't as accurate with the number I guess http://www.miata.net/garage/tirecalc.html

Yea i'm in north jersey roads are horrible in my area but ... 18's IMO look too small when the car is lower because the IS have a pretty big wheel well.. But that's just my 2 cents...

Koz

I would never use a 19s in Northern New Jersey. I have a cracked rim and the two fronts are wheels have multiple pot hole scares and a slight bubble in one front tire.

Koz

VF84

spindles on the gears of awd systems have been known to prematurely fail/wear out on other makes, due to different tire wear from lack of rotation. the awd system was constantly trying to compensate for the difference in rotations... just fyi.

don't think it's when you start with new tires the difference is the issue. u can indeed match up pretty similar od. it's when they're worn down without rotating that you start encountering problems.

almacruel

Yea trust me I know it sucks but lucky for me I have 3 cars so if I'm going someplace where I know the roads are bad I take my altima... And my daily drive I take the same roads so and know where all the pot holes are... I must say though the roads are starting to get better...

passnu2

iTrader: (33)

http://www.porsche.com/usa/models/91...s/?gtabindex=3
911 Carrera 4S Features
why does a Porsche have have the following??? you can go to the link above...
Cast alloy 8J x 19 front, 11J x 19 rear
235/35 ZR 19 front, 305/30 ZR 19 rear
Intelligent All-wheel Drive

I wonder how they do this on an AWD

19psi

exactly. just like i said in my post earlier in this thread. i know a lot of you guys are pretty intelligent, but i've seen that many of you overthink things when it comes to cars. this is one of those times. don't worry about the extra "drag" of a wider tire in the back, it's so miniscule that it will not cause a problem.
seriously, geta 275 tire and roll it on level ground. get a 225 and do the same thing. is it harder to roll the 275? the answer is no, it's not. and we as humans are basically 1 speed transmissions with limited torque, compared to a mechanically advantaged vehicle with a lot more torque.

passnu2

iTrader: (33)

Im with ya on this! I cant wait for the OP to put this set up on their car and show pics to let everyone see that it will work

Joeb427

iTrader: (1)

Another forum guy's opinion.
A so called Nissan service manager.
I don't know if he's correct or not.


I'm not sure if i understand what you're saying slipangle. the overall outer diameter? do you mean the offset? it is possible to find staggered wheels with the same offset but not likely. and even if you do that still doesn't fix the problem.

#1 the staggered setup (wider wheel in the back) will have greater traction than the front due to more contact surface with the wider tire, which is not good for the awd setup.

#2 the different offsets (which most staggered wheels have) create a different contact point to the surface of the road from the crown of the tire from front to rear which will in turn give a traction difference from front to rear, which is not good for the awd setup either.

Both of the above will not cause damage in a short amount of time like i said before but will cause damage! The overall inflated diameter is the most important thing with the awd setup but #1 and #2 above will also effect the vehicle over time. i see many people do it but i would just not advise it.

Non factory staggered AWD also causes understeer.



I have to believe this or Lexus would stagger the IS and GS AWDs.
Porsche and other vehicles come from the factory with a staggered setup.The Lexus doesn't.The engineers have their reasons.

passnu2

iTrader: (33)

This guy/gal is trying to save them from any issues. Most service places are not going to support aftermarket stuff and tell you all will be good. They don't want the risk of something going wrong and you then going back to them. The fact is this can be done. Yes Porsche sends there cars from the factory this way but what makes there AWD system any different then other manufactures? I think on many cars its a safety feature...lest face it most of us don't have this kind of set up on a car and i have read many posts on CL where the Lexus dealer rotated the 18" staggered setup? Its more of a safety precaution IMO. If you know what you are doing and pay attn to the overall diameter of the front and rear tires it will work. I may be at the Lexus dealer today to have TPMS done and i will ask the Tech when there what they think and how well the system will hold up and what the tolerance is.

Joeb427

iTrader: (1)

I'm curious as to what the Lexus tech says.He'll probably go with the Lexus policy,tho.

How the signal mirror covers working?
Mine are being painted.I hope to get mine done the next week or so.

passnu2

iTrader: (33)

the mirrors are working great! Well worth the few dollars and looking different.

I will see what they say. I know the family there so i will see who will be honest with me and i dont have an AWD so no harm for them to be honest with me. Im going to call them to see what they will do for me on the TPMS?!?!

Big Willy

I have staggered wheels, and not one issue. If the diferential was locked it would cause an issue.
Make sure your outside diam. of the tires is the same...Each tire Manufacture will vary a bit, so do some home work.

Darookie27

I hear what your saying. I asked My lexus service manager about it, and he talked to the techs, and they of course don't recommend it for the AWD. He told me that the computer & sensors for the traction control system are very sensitive. And since NO staggered set up is going to be able to run tires with exactly the same diameter, that as speed increases the differece in RPM (front\rear) will affect the system. Although I know that is true, there has to be some tolerence, even if it's to account for wear. They just won't tell me what it is....cause lets face it .1" is almost negligable....I have to wonder if the tires them selfs are maufactured at that kind of tolerence...

So now I'm torn.....

I almost convienced just to put 8.5 X 18's all the way around, just so Have the ablilty to have some lip, but not jepordize the car.

I'm really interested in the Varianza T1S's. Since they basiclly custom make them, maybe I could have the offsets staggered a little...and cheat...

19psi

the rear tires (wider) would only have greater traction in a situation where the front tires are slipping. how often would this happen in an AWD 250? pretty much never, not enough power
just going down the road, all tires have equal traction or else they wouldn't be turning at the same speed; the wonders of an open differential.
i dont know for sure, but most likely the awd system works on an IS utilizing a viscous center differential.a viscous center diff works just like an open diff if traction between front and rear is equal; i.e. going down the road, driving normally. only in the event of either the front or rear axles spinning at different speeds would the viscous diff tighten up and lock the diff. in that event, since our OD on the tires is the same, again, there would be no issues, since rotational speed would be equalized momentarily by the vcd.
the additional traction of the wider rear tires is a non issue. technically, since the drivetrain is rwd biased, the stickier rear tires would grip better than stock, keeping the center diff from having to do more work than it would if it had stock wheels and tires; thereby reducing wear and tear.

the statement about offsets being differnt sounds like some political wool being pulled over someone's eyes. of course the offsets have to be different, the wheel widths are different, but the outer lips would be in line with each other front to rear if the setup is correct. again, he stated that the traction difference would cause a problem. there is no traction difference if there is no wheel spin! wheel spin would be minimized because of the wider rear tires anyway. the only time there would be a traction difference is going around a corner, but guess what? all cars have traction differences going around corners, that's why 99% of all cars have open differentials to allow this to happen without drivetrain stress. the IS has open rear and front diffs, so, NO wear. even the center diff, being viscous, won't activate going around a corner because it takes a certain amount of speed difference to lock it up , which isn't attained by simply going around a corner. even if it were, it wouldn't be any more than stock, because OD is still the same, so rotational speeds stay the same.

i really don't think it's about anyone being smarter than an engineer at lexus, but rather economics. IS250 people would rather be able to rotate their tires than have a cool looking staggered setup; bottom line. awd IS250' s are the practical cars for practical people.

even the understeer thought isn't really applicable because the guy wanting to stagger his 250 says he wanted it for looks, not performance. reaching hte limits of the suspension and tires isn't going to happen for a daily cruiser, besides, all stock cars understeer anyway.