Wheel Fitment, Staggered? The Basics and Why

[MR2Coop]

so i thought id make this i didnt notice to many posts that were for the general population... it was moreso for "what if i ran this wheel with these tires would it fit?" and i thought it would be very beneficial if we got a post with alot of general questions to make decision making for other people a little more easy. a few questions i personally had were...

1. what does the difference between the front tire width and the rear tire width have to be, i heard 30 but is it true?(215 front 245 rear) and if it is why is it, what would happen if i made it 20, 10 or 40 in diffrence?

2. does running a double staggered set up have any performance value or do people only do it for looks, and does it give u less in performance?

3. offset offset offset, what offset is the prefered offset to get ur wheels flush with no rubbing or fender rolling(assuming your tire width is realistic)
and generally how wide of a tire can u fit with only rolling your fenders and not pulling your fenders. Also what offsets can u work with with minor or no mods.

4. Wheel width to tire width. generally what width rim can go with what width wheel, i was under the impression that 9in u can run 245, 8.5 can run 235... now i see people running 245 on 8.5 or even 255 but wouldnt this cause the tread to roll over? what sizes can u match to have max performance without losing any performance (corning and curvys included not just in the straights)

i know alot of these questions are generally speaking but i think it would help out the mr2 community if we put most of these questions into one thread

[Sh0ty]

1. The stock difference is 30 (195, 225) so that will work. increasing the difference will cause the car to tend to understeer, less difference will push the car to want to oversteer.

[MR2Coop]

ahh ok good to know, anyone else want to chime in to clearify some of these questions? i know theres some wheel/suspension guru's out there for the mr2 community

[EL PAALO]

1. 10mm difference for 91-92 (195/60 14 & 205/60 14). 30mm difference for 93-95 (195/55 15 & 225/50 15).
As Shoty stated, less size difference = more oversteer, more stagger = more understeer. Example: 215/40 17 all around will oversteer more than stock. 205/40 17 front and 255/40 17 rear will understeer more than stock.


2. The performance reason to run a double stagger is weight savings. If you run a 16x7.5 +30 with a 215/45 16 up front vs a 17x7.5 with a 215/40 17 you'll save at least a couple lbs. That can be a huge change in steering feel at the least.
It also looks great IMO because the mkii (and mki) is basically a wedge shape so the front wheel look larger against the body up front when they're the same diameter front and rear. Also, the deeper the lip on a wheel, the smaller the diameter appears to be (optical illusion draws the eye into the center of the wheel instead of to the edges) so if you use a small lip up front like a 17x8 +35 with a 1" lip and a 17x9 +35 with a 2.5" lip the front wheel will appear to be larger (further emphasized by the wedge shape of the car).
The double stagger is good for performance and looks, but unfortunately it makes tire choices tougher which often outweighs everything else.


3. Use gordaen's calc ....... his flush numbers and suspension clearance numbers came from me. My numbers are what most people use. Hellaflush and VIP style setups are changing that somewhat and on the performance side more people have been fitting 235/40 17 up front (some with no modifications). If your going to push my numbers, be prepared to measure, test fit, and use more tire wearing negative camber.
As far as tire clearance and fender rolling - flush numbers are for the wheels, not the tires - you must take into account the (actual) section width of the tire and whether it will overhang the wheel. There are too many tires and too many differences between tires of the "same" size to know exactly what will and won't fit with or without rolling. If you want flush and no rolling, do a little stretch (like a 235 on a 9). If you want to go beyond simple, once again, be prepared to do your own homework on the tire size you want to use, how much it will overhang the wheel, how far the wheel is from flush, and have coilovers so you can adjust camber to clear if you don't want to roll.
Offset will also affect oversteer and understeer. The tire stagger is not the only part of that equation. Track width is measured from the center of one tire to the center of the other. The center of the tire is determined solely by wheel offset. If you use a 9.5 +50 out back (supra turbo wheel) with a 275/40 17, you've actually decreased track width which will cause more oversteer although in this case the huge meat out back will bring things back in check. A better example may be using a common setup for the FN01RC: 17x7 +35 front with 215/40 17 and 17x9 +43 with a 245/40 17 out back. Front track width increased by 20mm (10mm further out board each side) and 4mm out back. Let's assume this is going on a '93 so the tire stagger is factory. In theory this setup will cause more oversteer than stock because the front track width increased more than the rear and the tire stagger stayed the same as stock.


4. Listed on any tire spec chart. Tirerack is a great place to look and they're also listed on all the tire manufacturer sites. Each tire has a specific wheel width range and it's listed on those charts.
The biggest "mistake" people make is going bigger than 225 on 7" and 7.5" wheels. People frequently use 235/40 17 on the back of a two with a 7 or 7.5 which is outside the spec for any tire I've ever looked at. 235/40 17 requires an 8" to 9" wheel by the books. You can certainly mount it on a thinner wheel, but the performance is diminished - the sidewall has more squish which makes it less responsive and the contact patch is distorted giving less than optimal grip. The unanswered question is: What is the performance difference between a 225/45 17 and a 235/40 17 mounted on a 17x7? I'll trust the tire manufactures recommendations on this one and use a 225/45 17 in that scenario.
Also understand that the wheel width recommendation is based on width AND aspect ratio. a 235/50 17 will fit properly on a narrower wheel than a 235/40 17 (but is unnecessarily tall for a 2).

[Sh0ty]

Can you run tires with an aspect ratio of 50 on the front tires, and if so, what kind of performance changes can you expect?

[EL PAALO]

aspect ratio is a % of width. the sidewall on a 205/50 15 is the same height as the sidewall on a 205/50 17, but overall diameter increased by 2 inches which causes clearance issues. The sidewall of a 225/50 15 is taller than a 205/50 17, but the 17 still has a larger overall diameter.

215/45 17 or an overall diameter of 24.6" up front is generally considered the rub point.

When you go with larger overall diameter tires than stock you're also raising the car which most would consider counterproductive to performance.

Tire Dimensions Made Simple - Discount Tire

[Sh0ty]

I'm running stock 15's which have a ratio of 55 up front, 50 in the rear. I was wondering if slightly reducing the front tire sidewall would negatively impact performance. I know speedo is routed to the rear wheels, so changing the fronts won't effect any instrument readings, right?

[MR2Coop]

thats alot of good information thank you very much.

now why was the 91-92 staggered diffrent from 93+, i understand the rear subframe and tie rods were redesigned but that alone changed the oem staggered numbers? or is there somethign else

so the only performance benefit to double staggered is pretty much a lighter rim up front giving u less unsprung weight? thats good to know and makes sense.

alot of good info ty

[EL PAALO]

Originally Posted by Sh0ty

I'm running stock 15's which have a ratio of 55 up front, 50 in the rear. I was wondering if slightly reducing the front tire sidewall would negatively impact performance. I know speedo is routed to the rear wheels, so changing the fronts won't effect any instrument readings, right?

most people use a 205/50 15 up front with no ill effects.

[MR2Coop]

i see mostly everyoen running 17s but how well do 18 or 19s fit and do they only fit in the rear forcing you to have a double staggered offset? or do 18's and or 19s fit upfront too... keeping performance and beneficial tire sizes in mind that is i know ANYTHING can fit on anycar but im talking in the practical sense

[Luni]

Im running 17x7s up front and can tuck a 215 sized tire up there, and Im running 18x8s in the rear and can tuck at least a 235 in back.

[EL PAALO]

Originally Posted by MR2Coop

i see mostly everyoen running 17s but how well do 18 or 19s fit and do they only fit in the rear forcing you to have a double staggered offset? or do 18's and or 19s fit upfront too... keeping performance and beneficial tire sizes in mind that is i know ANYTHING can fit on anycar but im talking in the practical sense

smaller is better for performance, but 18's fit easily up front, 19's in back only - practically speaking because even a 205/35 19 is too tall to clear the spring perch up front (it has been done though). Tons of folks use 18's all around.

[Sh0ty]

Originally Posted by MR2Coop

now why was the 91-92 staggered diffrent from 93+, i understand the rear subframe and tie rods were redesigned but that alone changed the oem staggered numbers? or is there somethign else

The difference was increased to help prevent snap oversteer. The stock 91-92 were 195 and 205, so 10, and then in 93 the difference is 195-225, so 30. Wider tires in the rear would increase grip in the rear, which would help keep it under control.

[MR2Coop]

ahh thx for all the good replies. now back on the subject of offset, me personally im looking at the 5zigen the GN+ model, with 17x7.5 43 up front and 17x8.5 38 in the rear, now obviously i am going ot have to use wheel spacers to make the wheels fit flush. my question is for people that run other offsets than 35, does it get to a point when putting that big of a wheel spacer is a bad idea and they're just better off finding another wheel that works better with our 2's? and why?

[EL PAALO]

always better to use a wheel that fits in the first place.
Why would you use spacers with the gn+ when they offer better fitment in the first place ..... ?
17x7.5 +35 front (6mm tuck) and 17x8.5 +30 rear (1mm tuck).

+35 offset is only flush on 8" width up front and 9" width in back - offset needed for flush fitment changes based on width.
Flush front
8+35, 7.5 +29, 7 +23
Flush rear
9.5 +41, 9 +35, 8.5 +29, 8 +23

[Sh0ty]

I think you're only supposed to use spacers up to 5mm on the stock bolts, otherwise you run out of thread room to get the lugs on securely. If you want a bigger spacer, you're going to need to replace the mounting bolts. I'd just stick with wheels that fit pretty close without spacers.

[MR2Coop]

oh ok i understand now, everyone always told me 35 offset 35 offset non of the threads ive read so far mentioned it was based off a 8 front 9 rear setup and that its diffrent with smaller/larger widths.. ty for clearing that up... someone mentioned a wheel clearance calculator earlier... would someone be able to link that on this thread?

[mr29180]

Nice info!!!! Well I'm running...

17x7 front 35 offset
17x9 rear. 40 offset

215/40/17 tires front
255/40/17 tire rear...

[EL PAALO]

Gordaen's Toyota MR2 Wheel and Tire Calculator

[MR2Coop]

thx for the link ill definitely be using it when i start picking out my wheels and such. i hope this post helps out when people start making decisions and maybe prevent a few overlaped threads with the same questions... thx guys