Holle Subi team , im very curious is its ok to run 17x8.5 front and 17x9.5 rear without hurting my center diff . Tire sizes are 235/45/17 front and 245/45/17 rear . If anyone has some real information please advise
I'd ask very seriously, and only to very serious people, if they have run a wider wheel in the FRONT -- what you are proposing is the opposite of what you ought to be examining.
The cars that have wider wheels in the back that are AWD cars do so due to different weaknesses due to what your car suffers from. They've also got better balanced chassis whereas Subaru is still, um, working on it I suppose.
There is certainly precedent for running a wider front wheel on a Subaru, dating back over a decade now. It was a stop-gap solution for performance during auto-x or similar events. However I don't know if those guys drove to the event and back home like that, or whether they switched to matched wheels for everyday driving (to protect their differentials).
So, it's worth looking into but your order is reversed. Ask around if anyone is running a wider front setup and ask if they do it every day or just for events. Disclaimer: If you blow up your differential you get to pay for it. Your diameter MUST end up identical front to rear regardless of width.
Last year I nearly bought a car with a wider front seteup but it made a lot more power than a WRX and was designed with the wider front wheels from the factory.
An RS3 with the straight 5 (because there is no better engine configuration known to humanity) will make over 450Nm of torque and (I think?) 270kW of power and wears 235/35 front but 225/35 rear.
I contacted a very popular local dealer in a very famous area locally and asked directly if they have a white RS3 ready to roll. Days later, I got an email asking me to call them and tell them what colour I wanted. Sweetheart, you're not getting $70K if you can't read. Then I got busy, could not decide which car to make some room outside my house, and here we are.
Nonetheless they run wider up front and with good reason.
Edit: checked latest model. They’ve gone wider both front and rear, but still offer stagger with wider front.
We already answered that. Get the same size. At the absolute limit of the cars capabilities a wider front may have benefit. However you won't be driving there 99% of the time so there is zero benefit to you staggering wheels.