Hey I've got a 1999 Grand Marquis LS and I have some 20x9" rims with a 30mm offset I want to put on my car. I ordered some General Exclaim UHP 255/35/20's from tirerack but a representative from tirerack called and said he wasn't sure they were going to fit without rubbing. Can anyone help me out? Have any of you guys put 20's on a 99 Grand Marquis? My tirerack order is on hold right now so I need to find out asap.

The new tire is almost exactly the same dia. as the factory tires (~.50" bigger), and only ~1" wider, given the 30mm offset you should be fine. the back tires will definitely be ok but the fronts may rub the fenders on sharp turns. Considering people have used 1" spacers with no problems you may be ok.

Disclaimer: I have zero experience with large rims and low profile tires so you may want a second opinion before you spend your money. Just giving an opinion based on information gathered from teh CVN.

actually the problem is the rims or the tires may rub the upper ball joint if the offset and width is to much.

Do a google search for tire calcs and put the factory specs in and then go from there.

I use this one

http://www.wheelsmaster.com/rt_specs.jsp

by th calculation I see using that tool You would want a 1" spacer on the fronts for clearance.

The 20" rims are

1.1" wider (tire)
.4" taller
2" more backspace with that offset which is why you would want to get a 1" spacer if not 2" spacer to reduce that so it is the same as the factory backspace of 4.2"

The guy from tirerack said my stock offset is 35mm? Is it 35mm or 6mm?



Those are my rims.

for a 99 it should be 6mm

03+ is the higher offset of 40-50mm

refer to This

6 mm offset on a 7 inch wide wheel is a backspacing of 4.236 inches
30 mm offset on a 9 inch wide wheel is a backspacing of 6.18 inches

Look at where your tire (not the rim, part way up the tire from the rim) is in correlation with suspension parts. You will need spacers for sure, for the front for clearance of the suspension, and in the rear for looks and maybe for clearance as well.

Hm, well they gave me 8mm spacers for free. But either way, I should be fine with those tires with the right spacers right? I'd rather not order the 245/35/20's.

8 mm spacers are about 40 mm less than you need. As far as running a 255 wide tire up front, I don't know, it will be tough unless you get the spacing exact.

I don't know what to tell you, I ordered wheels made for my car and they didn't fit (I used 6 mm spacers to get them to stop rubbing the spindle, but this is not a Panther), with that much variation in width and offset it isn't going to be easy, and probably not something that can be worked out in a message board unless someone has specifically done this, and that is what you asked for, but most of them are either for the 03+ cars or get zero offset wheels.

Well I ended up changing the tires to the 245/35/20 Kumho Ecsta SPT's. We put the rim on the car without the tire and it looked like it would be okay. I'll find out on Friday when the tires come in. I'll post up pictures.

Well I ended up changing the tires to the 245/35/20 Kumho Ecsta SPT's. We put the rim on the car without the tire and it looked like it would be okay. I'll find out on Friday when the tires come in. I'll post up pictures.

20x9" Edge Distill wheels with 30mm offset (not sure if they used the 8mm spacers I provided just in case) wrapped in 245/35/20 Kuhmo Ecsta SPT tires.

Sorry about the picture quality... camera phone.









Oh and by the way, my car rides a couple inches lower in the rear.

Back when I first bought the car...

at least it aint donked

looks great if you ask me. i've been wondering if 9's would fit. now i kno

Why didn't you get a wheel with proper spacing to start with? It'd look better if they were farther out.