Here's a picture of my 07 Grabber Orange coupe with the 18" Ford Racing black bullit wheels (M-1007-S1885B) if this helps at all:



Kevin.

 

I think 18's look perfect, 255/45-18 front and 285/40-18 rear. And It's as close as you can get to stock over all diameter while going up a size. I have seen some 20 inch rims that look ok on the Mustang but just not my taste.

If you keep the weight and overall tire diameter as close as you can to stock, or lighter, you should be ok on any size. Obviously the less tire you have between you and the road the rougher the ride will be.

Oh and for the record, we have two 05 Mustangs at work, Mine on 18's and the other on 20's. The guys around my age (36) and older like mine better, the younger guys say the 20's look better.

So age might have some thing to do with it, whatever floats your boat. Have fun with it

 

nynvolt,

Keep in mind, it is NOT just the overall weight of the wheel that makes larger diameter rims "heavy", it is the moment of inertia of those rims. As the wheels get larger in diamter, the rim is moved further from the rotational centerline of the wheel.

This hits you four ways: 1) the diameter of the rim is increased, which means it takes more metal to span the diamter. More metal, more weight and rubber is much lighter than metal. 2) The center section of the wheel is now larger in diamter, so it takes more metal to connect to the rim. 3) The center section is now larger in diameter, so you need more metal to maintain the same strength as before. And 4) Because you have more metal further out, you get hit with the linear increased mass AND with with a SQUARE increase due to the diameter. This is why increasing the size of wheels very quickly hit the point of deminishing returns.

 

A supercharger, big brake kit, and upgraded suspension negates all negative aspects of going with the 20s. It is like what I said before Saleen did it right. If the guy wants to go with 20s it is ok. Most of us are going to get an improved suspension, power adders and better brakes. If you slap 20s on a stock mustang you may notice the difference but how many of us have kept our cars bone stock?

 

If you have stock brakes, I recommend against 20 inch tires because the gap between the brakes and the rim will make the car look like it is running on bicycle tires. I would recommend 18 inch tires for many reasons: Better ride, less weight, bigger tire selection, many tire shops won't touch 20 inch wheels, bigger wheel selection, 2007+ cars have issues with presssure sensors (personal experience).
I have 20 inch wheels only because 18 inch wheels won't clear the calipers on the 14 inch Baer brakes. There is no issue with handling, the brakes fill the wheels, the supercharger more than makes up for the weight and the 20 inch wheels look great but if I had an option I would have selected 18 inch wheels for the reduced hassle if nothing else.

 

If I had to do it again I dunno if I would reconsider my choice for the 20's. Of course the ride on the 18" should be much better.

 

I'm Rollin On DUBZ!

 

I have 20s and lowered the car with a FRPP kit. In my mind it's not that big a sacrifice and acceleration etc is not that badly affected.

when you go for a big brake kit, you also have more room to play with

18s still look a little donut like and you still have side wall compliance problems and your car ends up handling like a porker. go with 20s and you wont look back

 

I'll take this opportunity to be a picture*****.... but first:

-big brake kits still look small on 20" wheels- in fact I think they look worse on 20s than they do on 18s

-As far as not a big difference in power or acceleration: just changing from the factory 17" to aftermarket 18" with 275/40 tires cost me 20 hp/tq on the same dyno. I can't imagine how much more it woulda cost me to go to 20s.

-I can't say I agree that 18s look "donut like".... depends on the tires you choose, see below do they look like donuts lol? And side wall compliance problems and handling like a porker??? Now, that's just plain crazy IMO.

Anyway, here is my poor handling, donut-looking ride LOL!:

 

Tom, the DD's and the drop! look good What springs did ya use!.....

 

Steeda Sports, only on the rear. Fronts are untouched, factory Ford.

 

Awesome!

I know you hear whispers in your sleep.......'its meeeeee, down in the garage...........please get me a shaker hoood pleeeease....'

 

I ran 20's and the FRPP Handling Pack on my 06'GT.It handled well but lots of feedback from road bumps.
On my 07 Grabber I run the 18x9 DD's TT-M's and just added Steeda Ultralight lowering springs and it rides really nice,handles well.I just ordered 18x10's for the rear.

 

...shaker...shaker...shaker...." I just sold one them CDC Shakers for $500.00 new,i found it at a swap meet for $$500.00.

 

I stand corrected, looks really nice on 18s and very svelt

The HP loss on the dyno I guess is due to the extra mass it takes to spin up, which would affect the early part of the curve, but surprised it hurt peak power and torgue?

If the wheels were different rolling radii, then the two graphs would be out a little right? But 20 ponies is quite a lot

 

My 18'' by 9'' FR500 Replica's by Rev. With 255 45 18's with Ground Force Performance Spring's 1.3'' drop in front and 1.4'' drop in the back.

 

Yeah you're right about the diameters. In my case, the 17" wheels with factory tires were just a touch taller than the 18" with 275/40s. But, that's the price you pay for helping to get the power to the ground anyway- burnouts and donuts were great on the factory tires, but racing sucked lol! Spinnin' ain't winnin' !

 

Tom did you by chance check the weight difference between the Flat Rocks and your DD's with the meat on! this was something I was going to do but at my age poo happens.........

 

Go with the 20's. IMHO opinion going from 17" to 18" is not worth it. Anyway 20's look right at home with the new body style.
I didn't really notice that much change in performance and like a choppy ride.

 

No I didn't, but I can say there is a noticeable difference. Next time I have them off, I'll weigh them if I remember. At my age, I'm too busy getting 'tang to remember all of these tasks.