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Aftermarket Wheels / Tires

Tires/Wheels 
328K views 628 replies 184 participants last post by  DGMchester 
#1 · (Edited)
Hi Have anyone put on any new wheels / tires on their 15 WRX STi yet? We don't seem to have a thread for it yet. Lets get one together :)

I'm expecting mine in any day now (Hopefully) And thinking of getting some 19's put on. The 18's seem a bit small for the wheel wells. Do anyone know what are some good offsets for them?
 
#4 ·
Aftermarket Wheels / TIres

I'm interested in keeping the 18 by going to a 275 width for summer. 265 gives a smaller diameter while the 275/35r18 matches the 245/40r18 diameter. I don't want to roll fenders though.


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#5 ·
Re: Aftermarket Wheels / TIres

I'm interested in keeping the 18 by going to a 275 width for summer. 265 gives a smaller diameter while the 275/35r18 matches the 245/40r18 diameter. I don't want to roll fenders though.


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I know on my 2011 you could do 275's on a Rota DPT +44 offset, on stock suspension but you would have to roll the rear fenders or you'd rub. Not sure if clearance is any different on the 2015 or not. Hopefully people can chime in soon! :tup:
 
#10 ·
Re: Aftermarket Wheels / TIres

265/40/18
How was the clearance between the inside wheelwell and the outside fender lip before lowering? Do you remember? Going to a 275 will only add 5mm per side for width but it will give me the same tire diameter as stock. Can you take some pics of your tires front and back inside and outside clearances in the wheel well? This will help others looking at options we have.
 
#17 ·
Re: Aftermarket Wheels / TIres

[URL=http://s30.postimg.org/528kb3sgd/image.jpg]Image Link
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That picture is before my coilovers and it fits great no rubbing or anything. And for the 22 offset you will maybe have to roll your fenders if you lower your car but if u don't lower u will be fine with the 22 offset.
Looks great! I wonder if on stock suspension with 18x9.5 +44 if you could run 275/35/18 with no issues?
 
#26 ·
Aftermarket Wheels / TIres

What is your setup? Wheel /tire, that would be great if I could run 18x9.5 +38 with 275/35/18 pilot super sports!

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Dude thats my future setup
 
#43 ·
Aftermarket Wheels / TIres

i test fitted 18x10.5 et30 Enkei Nto3+M yesterday with 265/35/18. Fitment was horrible they stuck out past the mudflaps. With lots of camber and good drop they would good. Sorry no pics
Are you saying the offset was 30?


Stock
 
#56 · (Edited)
Aftermarket Wheels / TIres

So then we're good with 275/35/18's? If so gotta start looking for a wheel. Whats the offset for a flush look? What is the stock offset at right now with the stock black wheels?

Another question: i dont really know how offset works. Does the rim width play a factor in offset? For instance, if i have a 18x8.5 +44, will it stick out on the car the same as an 18x10.5 +44
Stock
 
#64 · (Edited)
Re: Aftermarket Wheels / TIres

So then we're good with 275/35/18's? If so gotta start looking for a wheel. Whats the offset for a flush look? What is the stock offset at right now with the stock black wheels?

Another question: i dont really know how offset works. Does the rim width play a factor in offset? For instance, if i have a 18x8.5 +44, will it stick out on the car the same as an 18x10.5 +44
Stock


Wheel Tech Information - Offset

Offset is a critical factor in your car's suspension geometry. You want to stay as close to stock as possible. Anything much more than a 10mm change will have drastic affects on how the car handles. It's pretty universal that any offset below +40 will be bad for handling and road mannerism on a Subaru. You want to have the maximum offset while still allowing for suspension clearance. This however means the wheel will be further inset.

For what it's worth, people tend to overlook that flush fitment is bad fitment. You need to have the wheel and tires inside the fenders to allow proper suspension travel without rubbing.

That being said, bigger is not always better. It's only true to a point, and past that it will actually do more harm than good. What matters for grip is tire compound, not tire width. An STI equipped with 225/45/18 BFG Rivals will destroy the same STI riding on your stock 245/40/18 Dunlop Sport Maxxes. It wouldn't even be a close competition. There is a such thing as going too big in terms of both tire and wheel size. Wider wheels than you need means more wheel weight which means more drivetrain power loss, heavier steering, and worse braking. Ditto with running larger tires than you need but also add increased tramlining, increased risk of hydroplaning, and a LOT more stress on everything between the steering rack and hubs. On the previous generation STI steering rack failures aren't uncommon on all the street cars running 265s. That being said, there is absolutely nothing you can do on a public road that will be able to take advantage of 265-275 sizings. In fact, a good 255 offers more than enough grip and heat combating ability for anything you will do outside of a race track setting. And since it's lighter you will actually be faster than a similarly equipped car with a wider wheel configuration.

What you see on race cars doesn't always translate well to street use. Wheel fitment is a game of give and take, and sacrifices to steering performance, road characteristics, wet traction, and reliability are acceptable losses to race cars that need better high speed stability, peak grip, and additional heat resistance. On a road going car, you won't see these benefits from high speed stability or grip, nor will you ever overheat a half decent set of smaller tires because you can't drive fast enough or hard enough. The items that are worthwhile sacrifices for a track car are generally things you would feel in every day street driving and applicable for people who don't necessarily want to put added stress on different components without being able to see benefits from it.

Also, keep in mind that the Subaru Road Racing team is only running 265s.

 
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