07 GT/CS

Yes, I did search high and low for every post that I can find on 18 versus 20 inch rims and read every one I could find. It seems the answers are all over the board. I have the polished 18" bullits with KDWS tires that came with the car now. I scraped a rim going around a turn on the curb and when the tires are ready to go, I am debating on going to a 20 inch rim. However, I have seen several comments about a harsher ride, the ease of damaging the rim, and comments about the performance actually suffering. I think I read one comment that said the 18 inch rim is the perfect rim for performance for the Mustang. So, I have a few options including picking up a matched stock rim and keeping the same rims but going one up on the tires. Or, going with a whole new rim and tire setup. I am partial towards the Shelby Razor in anthracite. From a performance perspective, which is better? From a looks perspective, I think it is a toss-up. I am lowered now with Steeda UltraLites and have other suspension mods. The ride now is definitely more firm, but not uncomfortable. With 20's, I am concerned that they could push it over the edge towards a harsh ride. I don't show the car and it is a daily commuter that sees both city streets and long highway rides.

the procrastinator

If you already have a firm ride on 18's with your current suspension, it will only get firmer with 20's.

JMoraru

you can feel the road more with 20's, but i would not say that it is terrible. the roads around here are not tooo bad, but overall the 20's don't bother me. i also think they look much better than 18s on s197s. weight was not really an issue for me considering mine are 3 piece forged and they do not even really seem to weigh much more than my stock 17s

TonyN

I had the same debate a few months back. So I chose 19's and I couldn't be happier. Absolutely the best size for a S197. It's how the car should have came from the factory. It tightened up my handling without a harsh ride and they look fabulous!

Tires are a little pricey but there are becoming more and more 19's available in the market these days, so I don't think it it will be to bad in the future.

Good luck!

Glenn

the 20's did firm up my ride and when hitting bumps You fell it more. That being said if you can go with a little more sidewall (overall taller tire) that should help.
The razors weigh more than my stock rims do. Click my sig for a little more info

Torrence

Better cornering with 20's. Can fit most BIG brake kit's with 20's. 20's make the S-197's look way better, especially lowered.

Down side you feel more of the road, but that could be compensated by tire choice. Get the meatest tire possible and you should be ok... That's what I did.

07 GT/CS

The brake options is one that I had thought about and is a factor. I had just about convinced myself to stay with the 18's, but some good arguments for the 20's. A 19 would be ideal, but I see that in the Nitto 555's, they don't make one that is the same diameter as the stock tire, thereby throwing off my speedo and not filling up the wheel well. The 20's on the other hand offer more options and tires that are very close to the stock specs.

SoundGuyDave

No offense, but if you look at any of the road-racers on the forums, or even better yet, the NASA and SCCA racers, you'll notice that NOBODY uses 20" rims... They add more rotating mass, which means that the car is harder to accelerate and brake, and due to the sidewall height, they really don't "bite" like they should. For a given construction style, forged vs. forged, cast vs. cast, the 18" wheel will be lighter, cheaper, and perform better in a handling situation than a 20" wheel.

The biggest difference in handling is the tire. I would bet that most of the guys that went from 17's to 20's also went from stock tires to a high-end performance tire. Put the same tire on a 17" or 18" wheel, and you'll drive circles around the 20"...

Torrence

None taken....

In a PROFESSIONAL racing situation you are correct, no one would dare ride on 20's, that would only add to a loss. He has a street car so he has the option of choosing many different routes, so the direct speed racer route can be comprimised if he chooses.

What I gained in rotational mass I compensated for by have a TWINscrew S/C, 4.10's and an Aluminum driveshaft. So I really don't feel it. I wanted looks and power and control and that is what I think I accomplished with my car.

Guess it just depends on how you want your build to go.

LEO_06GT

Only comment I have is that with Shelby Razor's the biggest tire you can fit out back is a 275. If that's all you want then go with the Razor's but if you want a bigger tire you might consider a different setup.

uberPony

I have to sort of disagree with all of those statements.
I think 18s look the best, 20s are too much wheel and not enough rubber. Big brakes fit on 18" rims too (and 20s) and 20s definately will not corner better than a smaller rim.

V8Mike

I agree with this. I feel 18's with meaty tires is a better look than the 20's with the 'painted-on' tire look. It's all personal when it comes to looks obviously.

Doogie

I agree that 20s are just getting too big and tires too small. Especially if you have a convertble like me as the ride is already a bit stiffer than a coupe. When I do finally upgrade, it will be with some 18s.

Torrence

To each his own people..... Great to see difference of opinions... It's all about what you want and how you want your ride to look.

IMO the wheels that I have would look horrible in 18's... The 20's look way much better. Now on my stock bullit 18's I loved the look, just couldn't get the BIG BRAKE kit that I wanted.

I have a pretty meaty tire so it's not like I am running a super low profile tire which would make the rims look EXTRA big.

LEO_06GT

Good point. I totally agree that Razor's in 18's end up looking like 15's.

05GT-O.C.D.

I know 19" tires are more expensive, but that really is the best looking size for this car, IMO. Also IMO, 18's are too 'stock' looking and 20's are maybe slightly too big. I went w/ 20's and am happy with them, but based on what you're saying about your preferences I'd go w/ 18's or search for 19's.

(oh, and please nobody post a picture of some wild 18" rim and say... 'Does this look STOCK?' ... you know what I mean.)

SoundGuyDave

Does that look STOCK?


Sorry, couldn't resist...

I agree that "beauty is in the eye of the beholder," and to that specific point, literally anything goes, as long as the owner is happy. On pure performance merit, however, be it straight-line acceleration, braking, or cornering, an equivalent 18" wheel will outperform a 20" rim every day, in every way.

Wheels and tires make a much larger impact on handling than most people would think. The less mass the better, particularly since it's rotating mass, with all the inertia that implies. I don't hate 20" wheels, not by a long shot, but for me, I enjoy the performance of the car (it's not a full-on race car, either, as you can see), and as a result, I lean towards mods that enhance what I want the car to do.

Torrence

The good thing about 18's though, you get so many more tire options that you can't get with abigger wheel.... Also the diameters are alittle wider which is a great thing for those that want to go really wild in the back of the car.

Boltzman

City streets with 20's =

05GT-O.C.D.

Well, yeah... kinda.

I figured someone would post something like these - jedikd's