I'm currently running 18" staggered FR500 Anthracite wheels and thinking about going towards the 20". I don't know what's best at the moment and lately my front driver side has rubbing the back-inside of the fender well. I checked a few tire shops within the area. Nothing is wrong with the suspension just a few high tides (warps) or something on the tires. I've been looking for a new set a tires but I started thinking about 20" wheels. I'm told I need spacer in the rear for the 20" wheels and I'm not sure about tire sizes either far as what's best for it. I got 265/35/18 in the front and 285/30/18 in the rear. If I'm changing the tires and keep the 18" wheels I'm going for 245/40/18 in the front and 285/35/18 in the rear. If I get 20" wheels this is what I'm going for:

1: http://www.ebay.com/itm/191458110465?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT



2: http://www.ebay.com/itm/191456902382?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT




I have the 18" version of these wheels right now...

My car is vibrating because of the tires and one of them rear has a plug in til I figure out what to do otherwise. I caught a flat on Thanksgiving Day... I'm already at 103972 on the odometer it probably has less than that but oh well. There's nothing wrong with the wheels I now other than curb rashes. I keep losing pressure out of the tires and the combination of the car vibration that is worrying me like something is about to give out.

 

Carry the one that keeps losing pressure to a shop and ask them to fix the leak and balance the tire again. That might fix the vibration.

 

all are losing pressure but I guess it has something to do with the weather because when its cold that's when I can tell that the pressure has dropped

 

How much pressure we talking? And a constant loss like you gotta keep stopping and filling them or just stopped once to fill and now they are fine?

 

From a performance standpoint, what would be best would be to run the lightest wheel / tire combo possible, because rotational mass functions as a kind of parasitic drivetrain loss that takes more torque to accelerate, and it also take more braking power to stop. More unsprung weight also tends to be bad for handling and effective damping control and thus tends to exacerbate the less desirable traits of live rear-axle suspensions at the limit of adhesion.

If optimal performance is the end goal, you'd be better off sticking with 18"s because wheel / tire combos tend to get heavier with an increase in wheel diameter. You might want to ditch the stagger, too, because of the negative influence it can have on understeer and the transition from understeer to oversteer at the limit of adhesion.

If you just want to look cool, do whatever you want, and if what you want are staggered 20"s, then run 'em, by all means.

 

I would stay away from a 20" wheel. Even a 18" is pushing it due to the size of the wheel arch and placement of the spindle within the wheel well.

Remember when this body came out it was designed around 15-18" wheel whereas the s197 car was designed around a 17-20" wheel

 

Yeah, what PNY said.

Plus I would add that the larger the wheel, the larger the seal. If you're getting WX-related air loss at the bead, increasing the diameter of the bead gives you that much more area for that to happen.

One other consideration is availability and cost of the 20" tires. You may have plenty of money right now, but what about two years down the road? Especially in this economy, you might find yourself short of funds when it's time to re-shoe your pony. Will the 20" be an extra, say, $40 per set? And also, what if you history a tire somewhere, are 20" tires harder to find?

Having done absolutely no research on this, I don't know. You SHOULD know before you do something like this. I got snakebit both ways one time with my first British car, back about the time "Star Wars" came out, though in my case it was an oddball battery size that got me.

 

ok so I'll stick with the 18" wheels, but I was losing a 5-10 psi just about every month. Now that it's being mentioned I do have a hard time coming to a complete stop and its harder to accelerate

 

Ah, shock the teeny boppers & go "Old School" with a set of 17" like these & forget the "wagon wheels"! Then the wheels won't look like the cheapy chromed candy dishes you see today! LOL! Fat chance, huh?

 

Then he would be like almost every other new edge owner with cragar styled bullets.

Do a little research before you post, Mr D, that style and size was stock on this gen GT.