I was running a Mazdaspeed 3 in DSP, Traded that for the 10 X GSR. I have a pair of Hoosier 275/40/17's I would like to use on the rear of my X to finish this season out. What problems will I have with just running the stock yoko's on the front. One more thing, Gravel or Tarmac?

Thanks Mark.

NO. Dont do it. First because with AWD is best to keep the same tire size all the way around. Second It'll change the way the whole car handles. Lastly and more importantly, they are 17inch and stock Evo wheels are 18. NEVER mismatch tire size on AWD cars.

no. Dont do it. First because with awd is best to keep the same tire size all the way around. Second it'll change the way the whole car handles. Lastly and more importantly, they are 17inch and stock evo wheels are 18. Never mismatch tire size on awd cars.
:+1::+1::+1::+1::+1::+1::+1:

NO. Dont do it. First because with AWD is best to keep the same tire size all the way around. Second It'll change the way the whole car handles. Lastly and more importantly, they are 17inch and stock Evo wheels are 18. NEVER mismatch tire size on AWD cars.
:yeahthat::amen:

Also, I use Tarmac.

ASC off. Not OFF OFF though (did that once in the rain and went for a nice spin)

Not worried about tire size..... The yoko is .1" more in Dia. Tested it , everything works fine. Just wanted to hear from somone who has done it, and or what to watch for.

couple of things: In autox, the car tends to understeer, so fatter rears may or may not be helpful. Also, you'll want to measure the ACTUAL circumference of your fronts and rears to make sure it's within 1/2" or so, as the computer will get mad and disable S-AWC if it detects a mismatch. This can be caused by having uneven wear only, so important to measure.

Personally i think you should go track the car the way it is before making any changes.

no. dont mix and match on an AWD. same tyres, same width, same size please.

Don't use the 17s...you're pretty much stuck in the 18s now. I run 285/30-18 Hoosier A6s. And yeah, like everyone said, no mixing and matching tires.

I run ASC FULL OFF. Without it full off you won't get the car's true potential and will have more understeer. And run it in tarmac mode. Switch to gravel mode if it rains.

Holy Cow.... You guys are stuck on the 17" vs 18" Geometry. I just want to know if the yoko grip will handle the Hoosier pushing it around the site. The 275/17 Hoosiers I have are brand new.. They Measure 25.5" Dia. The Yokos will have over 1000 miles on them by our next event, They measure 25.6"... Not sure what that translates to in tire Height but I think by race time these tires will be almost identical. The Hoosier is 1.5" wider and has more grip I know.. Was just looking for a Autox/ tire guru that can help me get the best out of this situation. Tire pressure/ driving mode. Thanks Guys, I hope I don't come off as a dick. Just trying to save some Money. For next year I will find the right size 18" Hoosier to match the 17" hoosier I have on the back. Thanks

Just trying to save you transfer case is all we are trying to do.

Are you Serious !!!! OK, Tell me the Damage I will do when I buy a pair of Hoosier 275/35/18's for the front. Running the 17" out Back. I think you are going down a road you have never been before. Thanks for your Help though.

Wow. Seems like we are a little stuck on the problem of differing tire sizes. As you already know by now, there are some real risks associated of running different tire sizes, as most size combinations will not have the same diameter. You seem sure that the diameter is the same, so that part of the discussion is officially over. The next point is the handling. I'm not sure that a lot of guys here have experience with running a staggered setup, as it's highly preferred to have the exact same tire size all around, both for preventing damage to the drivetrain and also because a staggered setup is likely to adversely affect the handling of the car.
It is for this reason that I would recommend running whatever size you currently have on the car until such a time that all 4 tires are replaced by tires which share a common treadwidth at least.

Are you Serious !!!! OK, Tell me the Damage I will do when I buy a pair of Hoosier 275/35/18's for the front. Running the 17" out Back. I think you are going down a road you have never been before. Thanks for your Help though.

Do your thing. I could give a shit less.

Are you Serious !!!! OK, Tell me the Damage I will do when I buy a pair of Hoosier 275/35/18's for the front. Running the 17" out Back. I think you are going down a road you have never been before. Thanks for your Help though.


Everyone should cool off a bit.
Have you considered if a 17" wheel in the back will clear the brakes? maybe... Maybe not.
The Evos SAWC system is very very good but what happens when you put on tires with different coefficient of friction? The S-AWC is expecting one kind of behavior and compensates not knowing you have tires with differing grip levels. Handling will suffer. The brake balance will be totally off.
The different rolling resistance of the tires will cause stress on the diffs as the AWC tries to compensate.
If this is going to be just for an AutoX session or some such, have a blast. Driving any extended period of time like this, even just a track day may cause damage to the cars transmission/differentials. Your call, but I recommend against it.

yeah, how is this guy gonna run 17's? if he can i wanna how long he'll go before ruining his transfer case

Tire Dia. is same as stock. Just a little wider on the rear.

Evo x is an 18 inch wheel stock. Not 17 inch.

ummmm. if your overall circumference is within a centimeter of the fronts (lesser the better), and your inner contact patch is comparable to the fronts (ie offset & tire width), you'll be fine. Mess around too much with it, it WILL crap out on you.

BTW, a 0.1 inch difference in diameter denotes a circumference difference of 1%, which i think will be fine.

Evo x is an 18 inch wheel stock. Not 17 inch.

he will be making up the difference using the taller tire sidewall on the 17's is what he's saying. That's why he is giving us the overall diameter difference.

Evo x is an 18 inch wheel stock. Not 17 inch.
He's talking about the overall diameter of the tire, not the wheel rim. The tires he's got on the 17" wheel are taller than the stock tires, resulting in them being about the same overall diameter.

Why don't you forget about the rim size.... If I was running just the rims without the tires I can see your point. When the tire gets mounted to the rim, tire size makes the difference. A Hoosier 275/40/17 is the exact same size as a 275/35/18. Width =10.3 Dia= 25.5 Also, My other two Hoosiers 245/40/17's will not fit over the large brakes on the EVO.... Hense running the 275/40/17's on the Back.

Thankyou God of the Catalyst.... Now can you help me with tire prep for this setup?

There are a number of issues in regards to running different size rims on the front and back on an AWD car, but i will mention just 1 big reason. Rotating mass.

Its great that your 17" tire and 18" tires are the same size diameter, im happy for you. But now you could have a significant difference in rotating mass between the front and rear. Less rotating mass = unequal momentum at the front and rear. You are asking for more trouble than this is worth.

Holy Cow.... You guys are stuck on the 17" vs 18" Geometry. I just want to know if the yoko grip will handle the Hoosier pushing it around the site. The 275/17 Hoosiers I have are brand new.. They Measure 25.5" Dia. The Yokos will have over 1000 miles on them by our next event, They measure 25.6"... Not sure what that translates to in tire Height but I think by race time these tires will be almost identical. The Hoosier is 1.5" wider and has more grip I know.. Was just looking for a Autox/ tire guru that can help me get the best out of this situation. Tire pressure/ driving mode. Thanks Guys, I hope I don't come off as a dick. Just trying to save some Money. For next year I will find the right size 18" Hoosier to match the 17" hoosier I have on the back. Thanks

yeah your right but that is static diameter not real diameter when the completely different side walls are worked they will act larger or smaller than each other

Holy Crap, Does EVO mean Anal in some other language.... You guys are nuts.

Holy Crap, Does EVO mean Anal in some other language.... You guys are nuts.
lol. Like I said, you probably won't run across anyone here who would be able to offer you the constructive input you're looking for regarding pressures and such. Sorry man.

Where's EVO Dave when you need him....

Ill go back to basics because apparently thats what you need. Your car will perform like absolute shit. Here is some simple math for your situation.

1 = you have R compound Hoosiers in the rear.
2 = you have semi descent summer tires on the front.

1+2 = 3

3 = absolute shit performance with stupid amounts of understeer that the AWC will try to counteract and then realize this guy is retarded for putting two different size wheels and tires on the car and give up on you in the form of a ruined transfer case.

Youve read all the posts. Everyone has said its a bad idea. At this point you are just waiting for someone to tell you what you want to hear. Sell the hoosiers. Thats your solution.

I will be interested to know how much you have to change on the suspension to compensate for the difference in grip, front to rear. I don't have a lot of experience auto xing my EVO - I have only done it twice now. On my mustang, which was running Michelins in all four corners and I have tracked off and on for years, I worked on adjustments as much as possible to get rid of the massive understeer all Mustangs have. Eventually I got the suspension tuned reasonably well. Then I tried putting Hankook Ventus Track tires on the back only, and handling went to crap in a hurry. The Ventus tires' UTQG is 40, the Michelins were something like 240. The increase in grip in the back caused all kinds of problems in handling, which in a Mustang sucks to begin with. Needless to say, my track times got worse, not better.

I would think the difference in grip front to back in an EVO would cause problems with the AWC/AYC. I am by far not a technical guru on the EVO, but I would think the significant change in grip front to back would cause the various driveline control systems to work a lot harder than they should, especially at the limit. Given that the EVO is prone to slight understeer (at least mine is right now), I would think you are going to make that specific problem worse, requiring changes to some combination of damping, sway bars, caster/camber, etc, probably in all four corners.

Not trying to dogpile on with everyone else, but I would be interested to see if you can improve your times by changing two tires only - I doubt you can, without significant changes to the suspension to compensate.

I have done that with success, /not AWD / Rain event, Back end coming around on me big time, With the Hoosiers.... Put my 235/40/18 Re-11's on the rear with the Hoosier 275's on the front ,Hooked up the rear and dropped 1.3 seconds.

Point is, suspensions are tuned for specific setups. On a mustang, adding grip to the back makes a bad problem worse. A guy here in SD runs a Viper, adding softer compound tires to the back helped him entering corners, but hurt him at the apex and exiting - no gain in times. I have seen a few Porsche guys run staggered tire sizes (width and aspect ratio), but its because the car came that way - the suspension was set up for that.

And while there are the odd duck AWD cars out there that run different tire aspect ratios front to rear (like the Lamborghini Gallardo), the vast majority of them run the same circumference, width, and aspect ratio on all four corners (Volvo, BMW, Ford, etc etc etc). There is probably a reason for that.

Good luck.

Where's EVO Dave when you need him....

Running a non-staggered set-up and the same tires on all four corners. Hmmm wonder why? That is where he is.

I have done that with success, /not AWD / Rain event, Back end coming around on me big time, With the Hoosiers.... Put my 235/40/18 Re-11's on the rear with the Hoosier 275's on the front ,Hooked up the rear and dropped 1.3 seconds.

So you did this in a non-awd car and it worked. Yep probably.

This won't work in an AWD car. But I don't care. I look forward to seeing a thread about your broken transfer case, and maybe a broken front or rear differential. That bill is going to be quite a bit larger than a set of correct wheels and tires.

Not sure what smells worse... The Sarcasm or the Bitch meat... Thanks for your help, You are Great....

im pretty sure volk te37s will clear in 17", youll have to put them at all 4 corners though. i would do that myself if those wheels weren't so much.

why couldn't I still use the rota boost out back, and only have to buy two volks at a time.
then I could buy two more 275's sme as the fronts. who has the best price for the volks and are they the only brand in 17" that will work.

all i know about volks is they're expensive. there might be others that fit in 17", i just read on here that te37s in particular will fit. unfortunately this is an expensive car for upgrades and everything, why not spend a little more now rather than spend a lot later?

Sorry to bring this back from the dead, but did you ever do this? How did it work out for you?

Please don't tell me you're thinking of doing this also! I got some great deals on race tires before just like many others. Proper modifications do not have to be expensive

no, i'm not even planning on getting "race" tires. the most hardcore tire i'll put on my car is a dunlop starspec or similar. I'm not competing, when i go autox'ing or tracking, its purely for my own satisfaction. thats not to say i won't look at lap times and compare to others, but i'm not one to try and squeeze out that last .001 second... that and i like to have the same setup on the street and track...

i was just wondering how this whole thing worked out...

I would also like to know this^

Grippier tires in back... that's crazy understeer. I can see putting gripper in front to get the rear to rotate more but you're better off with the same amount of grip all around. This isn't fwd or rwd.

Also, I use Tarmac.

ASC off. Not OFF OFF though (did that once in the rain and went for a nice spin)

I also run with Tarmac and ASC OFF for auto-x and track.

I bought four Hoosier 275/35/18's , Found 3 18" SSR GT7 rims on ebay for 197.00 bucks. I used the 2 SSR rims up front with the 35/18's and used the Rota's from my Speed3 275/40/17 out back. Worked pretty good. Then I broke the stock endlink with the Hotchkis on full stiff. Got some Perrin Links ,Fixed...... Tein Mono Flex Coilovers will be here Tommorow, Car is put away ,will install in the Spring.

I bought four Hoosier 275/35/18's , Found 3 18" SSR GT7 rims on ebay for 197.00 bucks. I used the 2 SSR rims up front with the 35/18's and used the Rota's from my Speed3 275/40/17 out back. Worked pretty good. Then I broke the stock endlink with the Hotchkis on full stiff. Got some Perrin Links ,Fixed...... Tein Mono Flex Coilovers will be here Tommorow, Car is put away ,will install in the Spring.

You will love the Tein's, I will give you a heads up, set them on 12/16 front and 14/16 rear to start, 16/16 being the softest setting. I have found that to be my favorite setting for both street and track/autox. I ran 8/16 front/rear for about 2 months and it nearly beat me to death, it was great at the track but hell on the little bumps during DD. If you go, "Uhhhhhhhhh" while going over the little stuff it will make the sound like going "Uhhhh" into an oscillating fan, like when you were a kid. :neener:

If you are going to use the EDFC do it before the install, otherwise you will have to remove the rears to get them mounted.

Thanks Tek, I was expecting to get Bashed as per usual everytime I post Something. Finnaly something positive and Helpful.

You will love the Tein's, I will give you a heads up, set them on 12/16 front and 14/16 rear to start, 16/16 being the softest setting. I have found that to be my favorite setting for both street and track/autox. I ran 8/16 front/rear for about 2 months and it nearly beat me to death, it was great at the track but hell on the little bumps during DD. If you go, "Uhhhhhhhhh" while going over the little stuff it will make the sound like going "Uhhhh" into an oscillating fan, like when you were a kid. :neener:

If you are going to use the EDFC do it before the install, otherwise you will have to remove the rears to get them mounted.


so I'm gonna ask my typical coilover question now... how do these compare to stock strictly from a comfort and harshness point of view?

I bought four Hoosier 275/35/18's , Found 3 18" SSR GT7 rims on ebay for 197.00 bucks. I used the 2 SSR rims up front with the 35/18's and used the Rota's from my Speed3 275/40/17 out back. Worked pretty good. Then I broke the stock endlink with the Hotchkis on full stiff. Got some Perrin Links ,Fixed...... Tein Mono Flex Coilovers will be here Tommorow, Car is put away ,will install in the Spring.

I think putting the same kind of tires on all four corners was the right thing to do. For the record, I read in Grassroots Motorsports that when an Evo first won the Street Modified class, he had slightly wider tires in front (and had done the math to get the rolling diameter as close as possible).

It made sense to me because the Evo is slightly nose-heavy. And, regardless of weight, the front tires usually have plenty of work to do with steering and braking. Adding AWD adds to their stress. It may be fast, but once I started autocrossing my X, I never had a set of tires last more than 16,000 miles. Before that, it was 26,000 miles.

The tire store tried to blame my alignment...then I got them to do an alignment for me...then I autocrossed more and went through tires faster. :-D