Mitsubishi Lancer Evolution Forum banner

Staggered Tires 285/30 Rear - 255/35 Front, Any Problems??

20K views 187 replies 28 participants last post by  Badhazard 
#1 · (Edited)
Since I was a kid, I've always wanted a car with big fat rear tires like a Lamborghini. Now I finally have a car that can fit them, but here in Japan, no part of the upper wheel/tire can be sticking out past the body of the car. The rear of the X can fit a wide tire farther inside than the front, hence the need for staggering.

A 245/35 and a 285/30 would have the exact same diameter, but the X prefers to have a balance front to rear with all the computer/mechanical trickery, so I plan to put a grippier 255/35 (180 treadwear) up front with a less grippy 285/30 (240 treadwear) in the rear. I realize treadwear is not an absolute indication of grip, but it gives you an idea. This setup should give a fairly good balance of grip front to rear but will only be used on the street, so even without the balance it should be OK as long as the diameter is close enough. The 255s would wear out significantly more quickly due to treadwear rating and being on the front (faster wear on front of X). The 255s are 3.75mm more radius than the 285s. This is about the difference between the fronts and backs of the stock tires when I bought the car used a year ago. The previous owner had apparently not rotated the tires at all, not ideal of course, but also not completely unheard of. So anyway, the diameter of the 255/35-285/30 setup should balance out fairly quickly. I could use the new 255/35s with my used 265/35s (almost same diameter) for a short while to wear the tread down 1mm or so, if everyone thinks 3.75mm radius difference is just too much to start with.

Let me address several other issues that I believe people will also mention, ahead of time.

I know I will not be able to rotate front to back - obviously, so I will rotate L to R, unmounting, remounting and balancing them.

I realize the speedo will read about 4 percent more than actual speed and that the 285/30 tire will lower the car about 12.5mm (1/2 inch) and will leave more "gap" in the wheel arch. These are all fine with me and the lower effective gear ratio is actually a plus for me (slightly more "feel" of power in each gear).

The wheels will be Rays Gram Lights 57Xtreme 18 x 9.5 +30 at all four corners. These are within the approved width range of both tire sizes (see TireRack's site, tire sizes' page, click on specs tab). My calculations show that the rears should be almost perfectly flush with the body, at most sticking out 1 or 2 mm, which I hope I could get away with if the cops just eyeball it. I will use my other set of wheels/tires for the biannual car inspection test, where they are quite strict.

So as you can see, I've done my homework :nerd: but is there anything I have missed? Something else I need to consider? Could this staggered setup in any way harm my car? I certainly don't want to do anything to hurt my baby.
 
See less See more
#3 ·
No, you shouldn't do this. You will destroy your diff. The X should have the same size tires at all four corners. Some people have been able to get different widths to work for front and back, but none of those cars have been running long enough to see if the diff will go out (for the veterans, I'm talking about Paulekas who blew his motor and is now selling).

Seriously, do not try this.
 
#4 ·
Your not supposed to run stagger setups on awd cars. You should have bought a rwd car to do this.
 
#6 ·
He must've never heard of Paulekas. That being said, he's from Japan land, which is known for some awesome cars, but even more so for cars ruined by idiotic teenagers



 
#7 ·
Put the 285s on the front, they will fit easier than the back.
 
#8 ·
I know it's long, but did you all read the whole write up? I know that AWD cars are not "supposed" to run staggered setups, and yes I have done my homework. If the diameter of all four tires is the same, and the basic grip level at all four corners is similar, why would it do any damage to the diff? For an Evo 8 on the track, the tuners here in Japan recommend 255/40R17s all around with 9.5 inch front wheels and 8 or 8.5 inch rears. Obviously this gives the front slightly more grip to balance the inherent understeer in these front heavy cars. I often ran this setup on track days in my Evo 8 with no problems. But again, I do NOT plan to use this 285/30 - 255/35 staggered setup on track, only on the street.

And BTW, forgot to mention I'm on the stock MR (Bilstein/Eibach) suspension (called the High Performance Package here in Japan, home of some awesome cars and many idiotic teenagers). Originally from CA, btw.
 
#10 ·
Before folks babble on too much about not staggering the tires on AWDs, they ought to go and read about all the AWD cars that come with staggered tires from the factory.

The issue is diameter, as pointed out earlier, not width. The thread-starter can go ahead and run different width front/back, as long as they are very similar diameters. Or, because we don't have anything as pathetic as a VC on the center, he or she can go so far as to mismatch the diameters, too, as long as he or she disables the ASC, ABS, and ACD.

Whatever. I'm just here because I'm sick of folks saying that something about AWD makes staggering impossible. Ever heard of a Veryon or a Skyline?
 
#54 ·
ok first off, newer awd cars that have sophisticated systems dont run staggered tires because of the computer aided assists sensors and tables they use to make adjustments. secondly the veryon is a mid engine car that has a RWD BIASED system, and so is the GTR. The GTR is RWD until it detects a need to split and distribute power to the front and different wheels, and its also a RWD BIASED system, as well as the trans being in the rear. so i dont know what your trying to implement as information, ut you need to get more facts bro. also, the evo 8 and 9 are different chassis with different suspension layouts with a bias of front understeer. the X is not. it is made for balanced handling. ive never, ever, once seen an awd car that runs staggered tires UNLESS its AWD system is RWD BIASED. i have seen different width tire/wheel combos on the 8 and 9 like the op stated, but once you get full tuned suspension theres really no need.

OP, dont do this, your going to put more stress on your rear axles. its not about if the math is right to full the comp or whatever, its the distribution of force between 2 sets of different weight vs distribution of force between 4 points. at least thats my understanding
 
#15 ·
Has nothing to do with whether an AWD CAN have staggered tires. AWD, like any other drivetrain, does what it's designed to do. For this post specifically - your Evo has all of it's electronic goodies programmed for equal, symmetrical wheels at all corners. You will burn up/break drivetrains if you do this and drive like anything other than a Florida pensioner.

The sophistication of the Evo's traction systems are your enemy here in doing this. Plenty of Mustangs and Camaros down the road with purely mechanical systems waiting for you to drive them, though. Leave the staggered setups for cars designed or dependent on running them.
 
#19 ·
Only wheels with no offset/inset are "symmetrical" and a X's stock wheels have a +38. But I think what you mean is all the tires must be the same diameter and width because that is what the electronics are programmed for. I understand that, but if the diameter is the same and regardless of staggering, the grip level is almost the same, then how would the computer even know that you have different size tires on?
 
#28 ·
I read the post. But I'm just curious if you want the "Big rear tire look", why not just run a wide square set up and not worry about it. I run 275's all the way around and don't poke at all, but it is pretty dang flush. The difference between 275 and 285 is only .393 of an inch, which, eyeballing things from a distance, is very negligible. 275's are extremely wide for this platform, 10.828 inches. I will never profess to be a wheel fitment guru. But for such a negligible overall difference, why not just run the safe route?


2011 WW Evo X MR Touring
 
#30 ·
^now there is some thinking.

Also to note, if I did my math right. Based on the radius difference of 3.75 mm provided by OP, over the course of a standard oil change of 3,000 miles, the front and rear tires would have a difference of 265 miles on them. Or in other words, 265 miles of "slip" inside the center diff.

Like I said, if I did my math correctly.


2011 WW Evo X MR Touring
 
#35 ·
Yeah, that's a big IF, considering you're off by a factor of 10.

Go to TireRack's site and click on the spec tab of a tire in each size.

285/30R18 revs per mile 840
255/35R18 revs per mile 832

840 / 832 = 1.009615 (i.e. less than 1 percent more)

So over the course of 3,000 miles the "slip" would be less than 30 miles.
 
#34 ·
Put them on and look at the dash s-awc thing and see how much it locks.

Maybe if the car had the ACD tuned?
 
#36 ·
I know nothing about this, but I feel like if you ran a staggered setup on the street it wouldn't hurt anything. If the wheels aren't slipping why does it matter? The problem would be when launching, cornering at high speeds, and stuff that like which you (should) only do at the track.
 
#38 ·
Off of a GTR forum:

Work out the tyre height thus:

TyreHeight = (Width * Profile% * 2) + WheelHeight[mm]

Therefore 245/35/19 =

245 * 0.35 * 2 + (19*25.4) = 654.1mm

And 285/30/19 =

285 * 0.30 * 2 + (19*25.4) = 653.6mm

Heights of these two tyres are within 0.07% which is well within tolerace.
 
#40 ·
To all the naysayers.

Think about the dynamics of driving any car, and then driving a high performance car like the Evo.

The reason we have to rotate tires is they wear unevenly. Average difference between F and R is probably about 2mm radius when rotating, sometimes more but probably rarely less. If not, there would be no reason to rotate.

Cars don't drive in a straight line. They have to turn. When turning, the outside wheel rotates significantly faster than the inside wheel. We often have limited slip differentials to compensate for this and turning does not break your LSD. That's what it's made for.

Now consider a high performance AWD vehicle. They are designed to be driven much harder. When we launch the car, weight shifts to the back. The rear tires radius decreases and the contact patch increases. The front tires get light, contact patch decreases and the front tires want to slip, but the Evo does its magic and shoots us forward without a sound (well, from the tires at least).

Then we go into a left curve hard. The RF tire's radius decreases, contact patch increases. RR tire less so. LF tire lightens, contact patch decreases, and rotates slower. LR tire even more so, sometimes to the point of actually lifting off the ground (i.e. no contact patch and zero rotation).

Then all the dynamics change abruptly and unevenly when we get on to the gas hard, and sooner than with most cars because the Evo's wonders compensate for all the variables.

I would argue that my staggered setup on the street (driving reasonably safely) over the course of several thousand miles would be less wear and tear on the mechanicals than a day at the track with a set of new, same size tires all around.
 
#41 ·
And for those of you having trouble with the difference between "wheel" and "tire", the tire is the black rubber that contacts the road. The wheel is the metal thing that holds the tire to the car. These things are not interchangeable and it really doesn't make sense when you do so.

I specifically stated in my original post that the wheels would be the exact same size at all four corners, so the wheels are not a variable in my setup.
 
#43 ·
Look into the difference between our center differential and that of the GTR. Also note that GTRs have better weight distribution than we do and more torque, both of which means more weight on the rear tires at WOT. That's why GTRs have wider rear tires than fronts.

As to the radius of tires when it is squished by the weight of the car: that's close to irrelevant. Modern tires are steel-belted, so what matters is the circumference of the tire.
 
#45 · (Edited)
In for results.

FWIW my 996 turbo comes staggered off by .4" diameter OEM (larger front), but this car uses a crappy VC. The new 997 turbo with fancy Evo like diffs comes .7" off (larger rears). Humm?

Also, you need to take into account that not all tires are the same size even though they are the same 285/30 or what ever. Size varies by manufacturer/tire, this can greatly effect your revs per mile. If you can pair 2 tires with equal revs per mile, I don't see the issue. But I'm not sure.
 
#46 · (Edited)
If we're talking about a C4S, the fronts are only .1" larger in diameter, but we're way OT now.

Please note, if you ending up digging into the GTR drivetrain, that it's nothing like a Ferguson-type AWD, as we have. The GTR is a rear-default Haldex, instead. And it has the transmission in the rear with a second prop-shaft coming forward, so it's more like a Veryon or other AWD supercar than an Evo, even tho' the engine is in the front, like ours. GTRs are tarmac supercars, not rally cars.
 
#47 ·
As I mentioned before, the tuners here in Japan recommend a staggered wheel (not tire) setup for tracking the Evo 7-9. I used to run my 8 with 255/40R17 A048s at all 4 corners with 9.5 on front and 8.0 at the rear. The first time I went out on circuit it scared the hell out of me when I got lots of oversteer when in an S curve. At the time I didn't know that I needed to heat up the rears to operating temperature first before pushing hard on them. (The rears take longer to heat up.) After that I got a perfect 4 wheel drift. It still understeered hard in tight corners though (like a FWD). (BTW, on stock suspension)
 
#49 ·
What do they recommend for the X? I'd ask a reputable tuner and follow their advice.
 
#48 ·
I can understand why the staggered tires and unbiased center diff might not be ideal, but i don't see how it would cause serious damage.

Again, even if the torque vectoring assumptions are wrong, i don't see how you'd definitively break something. Maybe put a bit more wear on some parts. I can see how you'd get understeer/oversteer.

What if you get a bunch of mud/snow stuck in your rear wheels? Is your car supposed to fall apart?


Sent from AutoGuide.com Free App
 
#50 ·
I can understand why the staggered tires and unbiased center diff might not be ideal, but i don't see how it would cause serious damage.http://www.autoguide.com/mobile
The key to this is limited-slip device on the center diff. If it's something old-school, like a VC (old Evos and all DSMs, for example), which reacts to differences in output speeds, then anything more than a few percent difference will cook the thing to death in 50 miles. In contrast, if it's a mechanical or active, which respond to total torque, then you'll get more power and less torque at the end with the larger tires, which usually doesn't damage anything, but is seriously suboptimal when you have decent grip.

Given that we have an active center, the above is why I said that you can run different diameters on our cars if you disable the ACD, soften it, or just stay way from the go pedal. When the ACD is open, it's a wide-open spider-type center which couldn't care less about front and rear tires.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top