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Staggered tyre set up - 225 instead of 215

4K views 16 replies 6 participants last post by  Kodename47 
#1 ·
I am planning to change the rears from a 215/45 to 225/45 set up to make the car less tail happy and put power down efficiently on stock wheels. i am aware of that this is potentially putting the largest width tyre on stock rims and also that there will be a small speedo error ( circa 1%) and a potential loss in MPG. Has anybody done it and are there potential pitfalls to be aware of?
Thanks in advance.
 
#2 ·
The main thing you need to be aware of is the added sidewall flex you'll encounter when cornering.
I'd just double check the manufacture spec of the tyres your looking at and see if they recommend fitting them to a 7" wheel.

What tyres are you currently using?
 
#3 ·
The main thing you need to be aware of is the added sidewall flex you'll encounter when cornering.

I'd just double check the manufacture spec of the tyres your looking at and see if they recommend fitting them to a 7" wheel.



What tyres are you currently using?
Thanks Will. Goodyear Eagle F1 Asymmetric 5 currently.

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#9 ·
Indeed. These cars already with OE alignment and square tire sizing are already understeer biased which many doing performance/track driving dislike and tune out for closer to neutral grip balance. It seems very wrong to make it even worse by going staggered.
Just get 225 all around, this way you'll also retain ability to rotate tires to even out wear, will still be able to use spacesaver tire (which on cars with LSD like ours, requires in case of punctured rear for same tire to be fitted (normally - front) to rear, and spacesaver used on front), will simplify finding/buying tires, especially if partial replacement. There is absolutely no practical reason to go staggered except if one is nutjob with goal to fit widest tires possible without rubbing (a bit wider possible in rear) at expense of anything else. 225 are not that wide to need that. If wheels are also staggered width that adds inconvenience to sell them off later in future.
My friend, whose car had staggered tire sizing stock, hated several inconveniences from dealing with that. Now why change it, when you have from many viewpoints easiest to live with square sizing stock?
P.S. For less tail happy car i suggest two things. Better grippier tire model then simply going wider, and also add in alignment a bit more rear toe-in (well evened out at that).
 
#10 ·
If I was you, I'd look at getting a set of (atleast) 8" wide wheels and runnning a 225/45 tyre on them. I know several other SC member's are running this size without issue.
A 225/45 tyre won't affect the playfulness of the car and should give you that extra bit of grip without sacrificing turn in / sidewall flex when fitted on the wider wheel.

Now's a good time to order Michelin Pilot Sport 4's as they have money off at the moment.
 
#11 ·
I'm surprised you have this issue. When cold I can agree, but I've found the Assy.5 pretty unflappable in the warm, not tried a launch but a rolling 1/2/3 pull gives no slip. Still getting used to the step up in grip from the Primacys, where I could cause get it to slip between shifts. If you need the grip, go square setup IMO, so new wheels to suit a 225/235 option, but perhaps this is something else, like geometry, as others have said
 
#13 ·
A nice little review of UHP tyres if sticking with the standard wheel size


https://www.youtube.com/watch?v=2_utfLrFaOM&t=637s
This is what led me to deciding on the current Goodyears

I'm surprised you have this issue. When cold I can agree, but I've found the Assy.5 pretty unflappable in the warm, not tried a launch but a rolling 1/2/3 pull gives no slip. Still getting used to the step up in grip from the Primacys, where I could cause get it to slip between shifts. If you need the grip, go square setup IMO, so new wheels to suit a 225/235 option, but perhaps this is something else, like geometry, as others have said
I was trying to do a 0-100 so from stationary, so not rolling but happened across the gears. I will try again with TC off. :) The alignment was done when i got the tyres about 6 mths ago, so i will not expect that to be an issue.

P.S. For less tail happy car i suggest two things. Better grippier tire model then simply going wider, and also add in alignment a bit more rear toe-in (well evened out at that).
I do have quality tyres (Goodyear Asy 5) for OE size and 2 degree rear toe in.

If I was you, I'd look at getting a set of (atleast) 8" wide wheels and runnning a 225/45 tyre on them. I know several other SC member's are running this size without issue.
A 225/45 tyre won't affect the playfulness of the car and should give you that extra bit of grip without sacrificing turn in / sidewall flex when fitted on the wider wheel.

Now's a good time to order Michelin Pilot Sport 4's as they have money off at the moment.
Thanks Will. Was wanting to conserve some cash in this economic climate :) and hence looking for some cost effective options.
 
#14 ·
BRZ: i highly doubt you have 2 degree toe-in, car would have been nearly undriveable if so with insane toe wear. If camber is ok to change in degrees, toe is adjusted with less then tenhs of degree, and difference already often can be easily felt. For example my rear toe-in is ~ +0.12dg each wheel, 0.25 total.
I'm rather thinking that measurement unit in your case is in "mm" (alignment racks usually can be changed from degree fractions or minutes to inches or mm. Unit imho should be there in printout). You can use online toe calculators like these inches-to-degrees or degrees-to-inches. 2mm(if for each wheel), 0.15748" total toe for 215/45/R17 outer diameter is ~ 24.62", so for one wheel in degrees +0.18dg, total +0.36dg (or half of that, if 2mm was total toe).
GoodYear Asymetrical 5 are good road tires with grip on PS4 level (with maybe a bit less wet grip).
Imho your setup should have enough grip and if toe is like that, it shouldn't be tail happy, certainly not so if not driven on public roads like on track or doing something to intentionally throw off grip. Need more info, to decide what else might be off. BTW, does toe have positive + sign before value in printout (usual way to tell it's toe-in, with negative usually meaning toe-out)?
 
#16 ·
Always nice if people keep alignment printouts for reference or to ease suggest/debug if alignment caused issues.

To me this looks like OE alignment, except maybe rear toe-in +0.2' (minute, 1/60th of degree) per wheel seems very close to zero toe. Should be driveable fine (it's toe-out, that usually makes car feel abnormally willing to rotate), especially because it's even per wheels, but if more rear and under throttle stability desired vs what you have now, you may ask during next alignment for a bit more rear toe-in. Eg. +0.1 to +0.15 degree per wheel (or 6-9 minutes, or 0.04"to0.06"/1to1.5mm with stock size wheels). Or it's not alignment that made your car extra tail-happy, but something else.
 
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