VnCist00

I have a 05 mustang gt and i was wondering if I ger the Fr500 chrome wheels 18x9in the front and 18x10 in the back with the x10 with a deep dish, do i need to put on offset on my wheels so that the calipers and the breaks to fit properly?

Wicked Pony

I think with the deep dish wheels they use spacers to give enough clearance.

Philostang

We should have a general Tire-Tech thread for this kind of question. Don't get me wrong VnCist00, your question is a good question--so good in fact that this should be easy to obtain information. But it sounds like you're not clear on how wheels are measured.

So here's some basics: (most of this from other posts I and others have done)
1. All wheels have an offset measurement (you don't "put on offset" to any wheel). Offset measures the distance from the wheel hub mounting surface to the centerline of the wheel. Positive offset (or increases in the offset #) brings the wheel in closer to the hub, while negative offset (or reductions in the offset #) brings the wheel out further towards the fender. This distance has a great impact on how the supension works within the geometry of its design parameters. Since it should've come from the factory with an optimized offset designed into it, keeping the offset in the same range as stock is a good idea (unless you have good reason to suspect that the original design was flawed).

2. 2005-06 Mustang GT wheels come in two sizes. The 17x8" have +45mm offset, and the 18x8.5" have +50mm offset.

3. Backspacing is not the significant measurement w/respect to suspension geometry. Backspacing is derivative of offset (for a given wheel width), but it is only relevant for clearance purposes. For example, you can keep the offset the same, move to wider wheel, and you have a new backspacing--but who cares (assuming you clear other suspension components).

4. "Deep Dish" is a non-technical term that generally denotes a wheel with a wide lip. For any given wheel width, the "deepness of the dish" will be determined by two things, design style and offset. Our very own fairlane292 repeatedly posts an excellent explanation of offset with links (his most recent is found in "RE: Ohh no! new wheels stick out! help."). The bottom line is that for a given design and offset, there is no extra change in the wheels mounting that would result from wheels being "deep dish"--they'll either be deep or not once you figure these two other factors in.

5. Specific to your proposed combo, this has been done already, so the good news is that you're in safe(ish) waters. What is tricky is that our calipers seem to be rather large (or placed far outboard in some funky way). This means that the specifics of a wheel design (as opposed to its measurements) play a big role in determining if it will work on our cars. This is the problem Mustang Tuning ran into with its "deep dish" offerings, so they included spacers to help clear the calipers. From what I gather, the design of the wheels they were using have been changed so this is no longer necessary for their latest batch. (Note: this was a rumor I heard, so don't hold me to it. EDIT: evil stang just confirmed this in another post, the design has changed no longer necessitating spacers.) But the moral still stands. Two different wheels that measure out identically may not both fit our cars. You need to find someone who has first hand knowledge to say for sure...and you have to trust them.

Hope this helps. Welcome to the world of wheels!

Best,
-j

VnCist00

thanks man