19s or 20s?
 

From a performance standpoint should I got with 19 or 20 inch wheels? I want to try and blend my straight line performance while still being able to maintain daily driveability. Would 19 up front and 20 out back make any difference? The biggest tire I would put on the rear would be a 305.

20's offer more tire choice's, but a loss of power. 19's great but limited to tires, and with with a drop look good.. Shelby's run 19F 20R, and looks very good. as far as tire choices im still searching myself..

for the best performance, you want the lightest wheel you can get.

What mid west said. The weight matters more than the diameter. Not much but a little. The whole 19" and 20" staggered never made much sense to me. If anything you'd want 20" in the front and 19" in the rear. haha. Adding weight/diameter to anything that rotates with the motor is what hinders performance. Unless you're that anal about .1 -.2 seconds I'd go with the 20s. 1st for tire selection. 2nd for looks.

Why not just a nice set of 18's with a 1'' drop all around? Nice and subtle.

19s or 20s?
 

20s
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Ya I never understood putting a larger diamater wheel in the rear either, other than for looks. Its best to get a light, wide wheel for performance. Obviously even going wider will cause some added weight but you will also increase your traction surface area and it will improve handling a bit more.

Looks great which wheels are those?

19s or 20s?
 

TSW Valencia's Staggered 20s, they are actually for sale, I want to get the Staggered FR500s instead. I'm to OCD these wheels are Matt Black, I want the Gloss Black for my car. I'm asking $1000 OBO for the wheels, the tires aren't for sale. If your interested hit me up 254 630 7408.
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18s > *
I also never understood people throwing 20s on a Mustang but everyone seems to do it. I guess it looks good on some cars but definitely not ideal from a performance standpoint. Best tire selection is going to be 18s and your ride quality won't suffer much because your not riding on rubber bands. My wheels weigh 17lbs Idk of many 19-20 inch wheel even close.

Truf, 18's for performance. 18x10s in the rear with a drop is plenty for me. 20's I just think rap video for some reason. :signs16: When doe right it looks gd but like I said just not for me.

Only heavy cast wheels will hurt performance. There are plenty of quality wheels out there to choose from in a 20 diameter that are lightweight. My car is a perfect example of that.

In my opinion, 18's are way too small for these cars due to the size of the large fenderwells. 18's are just too small to the point almost look like a spare tire. These new 5.0's are quite large cars especially when compared to the fox 5.0's back in the day where 17's were the norm or a custom wheel was an 18 to fill the fenderwell.

When it comes to wheels, it's especially true, you get what you pay for. If you buy a "cheaper" wheel, it's going to made cheaply using cheaper, heavier materials.

Larger wheels also affect the gear ratio. 18's are to small in your opinion but with a drop it looks perfect to me. 20's just look too big.

Unless one is a major track whore, the minimal changes to the gear are hardly noticeable. Only stockish cars would really notice it. If you any kind of decent power its not even noticeable.

Wrong. Wheels have absolutely no relation to gear ratio.

Tire diameter effects gear ratio, but you can choose tires for larger wheels that have an equal tire diameter as stock 17, 18, or 19's in 20" sizes without affecting gear ratio.

That being said, if you choose tires with different diameter than stock, say approx. 3/4" shorter or taller, the effect on gear ratio is minimal, about 3% on average. At 70mph you'r speedometer would be about +2mph with smaller tires or -2mph with larger tires.

You don't lose power if the overall weight of your 20" wheels/tires are the same overall weight as the stock 18" or 19" wheels/tires, which isn't too hard since the factory wheels are usually on the heavier side.

Agreed, the right 18" wheels can look nice, but you need to know what your plans are for the brakes, as more of the 18" wheel choices will not work with the larger 14" Brembo brakes, or other big brake kits.

The Corvette has done this since the C5 in 1997. Other car high performance car manufacturers do this as well, so apparently there is real benefit when tuned and setup. Just because it doesn't make sense doesn't mean we should fear it.

At that point you will sacrifice ride quality. Thats why if the car is lowered 18's seem to work fine.

Most people don't realize that the Mustang comes with several different diameter tires, spreading over 1.1" in difference.

V6 with 17 = 28.0"
GT with 18" = 27.2"
GT with 19" A/S = 27.7"
GT with 19" Brembo = 27.2"
Boss 302 rear = 26.9"
GT500 with 20" rears = 27.9"

In this regard, if you had a normal 245/45R19 (27.7") All-Season equipped GT, which is .8" taller than the 285/35/19 (26.9") rears on a Boss 302, and then jumped to to a 20" 285/35R20 rear tire (27.9") would give you .4" shorter sidewall than the stock 19" AS tires, but a 100% equal sidewall height to a Boss 302 rear tire.

Additionally, the 20" tire at 27.9" rear tire will give you a better ride than the 26.9" rears, while giving a little more overall grip from a slighty larger contact patch.

And there you have it. Solid post sir.

18s are definetly noticeably smaller when comparing to 19s and obviously more noticeably with 20s. I myself am tempted to go the 18s route on the Forgestar FR5s I want buy, but in the future want to go big brake as well (brembo at a minimum) and don't want to have to deal with getting different wheels again. I just hate how 19s are such the odd cat with tire selections and 20s are EXPENSIVE!

19s or 20s?
 

Excess rotational weight is horrible for drag racing, but its not always a bad thing for road racing (and even drifting). The extra weight on the axles help keep it planted in the corners. It's on off the reason that help ILE and ZL1 pull more Gs than GT and Bosses. Its not all about the IRS. That extra weight help keep them planted.

For those against the 20" wheel thing, with the 2015 Mustang right around the corner, I would assume that there will be a 20" wheel/tire option available from the onset. Here's a quick history on the tires sizes offered:

1979-84 Mustang = 14" (forget the Michelin TRX metric sizes)
1984-86 Mustang SVO = 16"
1985-90 Mustang GT = 15"
1991-93 Mustang GT = 16"
1994-04 Mustang GT = 16" std, 17" opt
2005-09 Mustang GT = 17" std, 18" opt
2010-14 Mustang GT = 18" std, 19" opt
2015-?? Mustang GT = 19" std, 20" opt

I ride on 19" Brembo's, but 20" wheels in a few years will look pretty normal on a Mustang from the way the trends have gone over the last 35-years.

Weren't you have a lot of traction problems at Ennis?

+1

All the high performance cars use a staggered wheel fitment. Corvettes, Vipers, Ferraris, Porsches etc. Even the GT500 comes stock with 19s front and 20s rear.

As others have stated, wheel weight makes the most difference for unsprung weight. TSWs Nurburgrings are excellent. I saw one member on another forum with a 19X9.5 TSW N that weighed 22lbs. In that size is it definitely lighter than stock AND allow for a larger brake kit. Also on those other cars, because the front fender of those exotics are generally much shorter than the rear fenders, if they ran same size front and rear wheels, the fronts would look bigger.

-Alex

Also keep in mind when you opt for larger wheels, most likely, you will be opting for wider tires. Wider means more tire which means more weight.

-Alex

No traction until 4th gear most runs... And that's if second gear wouldn't lock me out. My car is running Star specs which are more suited for road course/autocross use. Hard sidewall and require a decent amount of heat to grip anywhere, not to mention a 275/35/18 which changes my gearing quite a bit. I'm into 5th gear quite a bit to hit my 113mph trap lol I honestly think I would have been better on the stock all season Pirelli tires.

This thread is all over the place, I run 20x10 and 20x11 wheels and they are about 17lbs lighter per wheel then the stock 19" Brembo wheels. Granted to get that weight loss in a 20" you will have to spend a little money for them. As far as ride quality, I have yet to have a complaint, most everyone comments on how comfortable it is. Suspension setup and the Recaro seats have a lot to do with that as well. Nick/Pepper is right though, if you throw some thin tires on there, the ride is going to suck. As far as looks, pretty sure most the mustangs run with 20" wheels once they go aftermarket. From all the ones that I have seen, they only look bad if the wheel design/finish is lame, or if the fitment is wrong.

Edit: As far as the OP is concerned, I wouldn't even consider 19's, its a waste of money as far as tires go, 18's and 20's give better options for track/show use. Just my 2 cents though, I take my car to road courses as well as shows so I am a tad biased.

Remind me of the wheels you have again? That's an impressive weight!

Forgeline S3C3 (I think thats the right model number). They offer monoblock wheels as well which are even lighter.

Wow they have some really nice wheels! Prices are pretty steep about $1,200 a wheel. Get what you pay for I suppose.