I've been considering rims as a first mod, since many on the board have mentioned the greatly improved handling. Maybe I'm just tired or my brain isn't working correctly right now, but I realized that I'm in the dark about offset. Could you please tell me about it? Thank you all so much!

Check http://www.tirerack.com/wheels/tech/offset.htm . They have a really good area that discusses offset along with many other basic things about wheel fitments.

Ooh! Excellent link! Thank you so much :D

No Problem. :)

As far as I know, Subaru offsets are:

7" wheel=53mm
7.5"=48mm
8.0"=42-43mm, but will probably still have some rubbing, depending on diameter. Tirerack told me by email that I shouldn't even try to run 215/50R16 tires, or I would probably have rub.

I personally would not go with anything wider than a 7.5 inch wheel and with an offset and lower than 48mm. This is just being safe.

Originally posted by ImprezaRSDriver
I personally would not go with anything wider than a 7.5 inch wheel and with an offset and lower than 48mm. This is just being safe.

Same here. I'm sticking with my stock wheels and getting either BFG g-Force KDW's or Michelin Pilot Sports in 205/50 depending on just how much I am willing to spend when the time comes. If I were going to get wheels, I really dig the 911 Turbo-ripoff Mille Miglia Cup 3S sports, with 215/45 g-Force KDs. That'ss about a $1900 setup though, and I don't thnk they'd be $1400 faster than the Pilot sports.

Originally posted by BAN SUVS
As far as I know, Subaru offsets are:

7" wheel=53mm
7.5"=48mm
8.0"=42-43mm, but will probably still have some rubbing, depending on diameter. Tirerack told me by email that I shouldn't even try to run 215/50R16 tires, or I would probably have rub.

I ran 215/40-16 kumhos 712's on my stock RS wheels. The sidewall was straight and not bulging. Im sure I could have put 225's on with rolling of the fenders.

-scu

Originally posted by BAN SUVS
As far as I know, Subaru offsets are:

7" wheel=53mm
7.5"=48mm
8.0"=42-43mm, but will probably still have some rubbing, depending on diameter. Tirerack told me by email that I shouldn't even try to run 215/50R16 tires, or I would probably have rub.
Very useful information as well, my post whoring brother :D I'll have to remember this when I go rim shopping sometime. Thanks!

Originally posted by Scubaru
I ran 215/40-16 kumhos 712's on my stock RS wheels. The sidewall was straight and not bulging. Im sure I could have put 225's on with rolling of the fenders.

-scu

I could handle that setup for track days, but I don't want to spend the extra money for the spare set of wheels and tires. Also, stock tire diameter is 24.878 inches, but the 215/40 is only 22.772... that's a HUGE difference in gas mileage, speedo calibration, and most importantly, odometer! When you reduce the diameter of your tires, it causes your odometer to turn faster. Since almost all of intend to keep our cars for a long time, it could easily be worth 10,000 miles added to your cars true mileage over its lifetime.

But yeah, for track setups, who cares?

On a GDA, your offset should be between 48 and 53 IIRC.

Yeah, there is actually a lot to consider when buying tires and wheels.

wow! i completely overlooked the fact that you could have a smaller offset for wider rims...my dad thinks you can only use 53mm....

Originally posted by ImprezaRSDriver
I personally would not go with anything wider than a 7.5 inch wheel and with an offset and lower than 48mm. This is just being safe.

How about some 17 x 8.5 wheels! Nothing like and 8.5 wide wheel!

Originally posted by scsi
wow! i completely overlooked the fact that you could have a smaller offset for wider rims...my dad thinks you can only use 53mm....
Not to mention more room for brakes..BIG brakes :)

48 to 55mm for the sedan

my dad wont believe me......O_o how do i explain this to him =\

funny how I have +40 offset 7" wide wheels and my car is lowered....and I have no rubbing :p

What matter is the actual width of the tread at the top of the tire, and how close the outside edge can get to your fender. If you have 17s but a very short sidewall, like 215/35 or 215/40, you'll be ok with a different offset. but changing the offset and diameter of your wheels can have side effects like bumpsteer, harshness, uneven wear, etc.

Originally posted by BAN SUVS
What matter is the actual width of the tread at the top of the tire, and how close the outside edge can get to your fender. If you have 17s but a very short sidewall, like 215/35 or 215/40, you'll be ok with a different offset. but changing the offset and diameter of your wheels can have side effects like bumpsteer, harshness, uneven wear, etc.

so its probably best to stick w/ 53mm no matter what sizes and stuff then?

Originally posted by scsi
so its probably best to stick w/ 53mm no matter what sizes and stuff then?

The answer to this is no. The reason being is because the offset of the OZ P1 wheels in the 18x7.5 runs a 48mm offset because the wheel is wider. So the offset is based on the width of the wheel. OZ compensated the width by lowering the offset.

if you change the offset, doesnt it change the geometry of the suspension or something like that? =\

Originally posted by scsi
if you change the offset, doesnt it change the geometry of the suspension or something like that? =\

Depends. The idea of the offset is to keep the center of the tire's footprint well, centered. If you widen the tire, but don't move it inside or outside to compensate for the width, then yeah, you get geometry changes, hence bumpsteer, uneven wear, etc. But if your chenge in offset cancels the change in width ( i.e. matching +10mm in width with -5 mm in offset) you are ok, up to a point. Fenders or not, you'd have some problems trying to compensate for 40 or 50mm in width for sure.

So, when changing things other than tires and wheels, such as brakes and suspension, we should consider the relationship of the components we are upgrading with the design of the car and remaining components which are not being upgraded?

Of course. But with brakes all you have to worry about is whether or not they will fit in your wheels. The good companies are very helpful about that if you ask.