kevinmalec

WOW!!! Great looking Cobra, GT500!!

05 Mustang

here's my old 2005 Mustang GT



fronts:
20x8.5 w/ 255/35/20's
rears:
20x10 w/ 295/30/20's

JMO, I'm a huge fan of 20's, but reading your concern about the surrounding area that you will be driving on, I just want to point out that the 18's will definitely ride nicer and take more abuse (pot holes) that the 20's will. The smaller tires do not like pot holes and depending on the size of the pot hole and how you hit it, you may not like the end result. On the flip side, you can always drive "on guard" and if you see something or know of a certain pot hole, just avoid it. When driving, I'm always paying attention to what's coming my way....and when on the interstate, I stay several cars back just in case something unknown comes flying out from under a car. That'll give me time to react.

Nuke

Lot's of opinions and things to consider for your personal decision.

1. Mass - Larger rims usually mean more weight. Some don't mind; some do.
2. Handling - see #1 above. There are quite a few threads that discuss the affects of heavier wheels and shorter sidewall.
3. Sidewall - going to a larger wheel means going to a smaller (shorter) sidewall. Many of us "more seasoned" (a.k.a. older) folks are attracted to larger sidewall which simply amplifies the S197's retro appearance. Personally, I'd love to put a series 60 tire with RWL's on an S197. I cringe when I see ANY vehicle with huge wheels and what looks like a big rubber band for a tire. Sidewall height is also related to #2.
4. Longevity - There are a number of folks with 20's that state they've had to repair or replace rims due to damage from potholes and other impacts. This is related to #3.

This is your car. Make it reflect YOUR personality. It's good that you're looking for input to assist in making your decision.

Burrosito

I myself was going through this same decision. (Well, still am since I'm a long way out from getting rims and tires :P ) I think 20's with decent rubber really do make the car look great, especially with a nice body kit. But I think 18's are good all around, for daily driver and the occasional fun/race, as long as you have enough meat on them.

When I'm ready, I will probably go with 18's, and some thick rubber. I currently have the stock 17's.

05 Mustang

+1^^

...and it's good that you are taking into account your surrounding area in your decision making, because it will affect how your car rides, which in turn, will affect your overall happiness or not!

Riptide

The smaller the wheel and tire you can go with the better for performance. I wish I had stuck with 17x9s on my car.

IWinULose

Depends on what you mean by performance. Staright line drag? Sure. That seems to be the only thing anyone is worried about around here though, so yeah. But I am fairly certain that a wide sticky high performance tire with a little sidewall on a 20x10 wheel is going to out-handle any narrow big sidewall tire on a 17x9.

Also, someone mentioned weight. There are lightweight 20s to be had.

I really like 20s on the S197. Before that (new edge), 18s would have been my limit. I am glad to see the OP is considering a number of factors before purchasing. In the end, he'll be happier than if he'd just have impulse bought something.

distantsoldier

I figured I'd throw in my 0.02
My car is lowered...18X9 front, 18X10 rear - GT4s
I like the look of 20's on a show car, but a go car still looks good with 18s and doesn't lose as much performance.

While it is true you can get forged (lightweight) rims, they are extremely expensive from my experience, as well as the tires being more expensive for 20's than 18s. One of my friends just got forged 18X9, 18X10 wheels for the tune of around $4K...too expensive for my blood.

You can see my car in my sig.

rford426

When I was getting wheels I was set on 18s but they were on back order and ended up with 20s and I am SO glad they were on backorder and I got 20s..But which ever you end up with they won't look there best unless lowered imo!

Riptide

Certainly true. It's difficult to find a happy medium between the two especially if the car has a lot of power. That said, most people do seem to do most of their racing in these cars at the drag strip or on city streets.

And light 20s are gonna cost some bucks I bet. Especially if they are wide.