Have a look at the "Replacing Stock
rims and tires" thread...
Web sites like tirerack.com and Bigwheels.net are set up so that you can determine fitment. Not only can you determine fitment for the wheels they have, but you can get worst-case
wheel diameters, offsets, and widths. Once you determine those values, you can go to many other sites and plug in those values directly into their search engines. In addition to fitment, you'll have to check for overall
wheel diameter so as to keep your odometer within tolerance. There are calculators for that at
http://www.rims-n-tires.com/rt_specs.jsp. I suspect that for a 20"
rim, you'll end up with a PXXX/30R20 (very low profile) tire if you want an overall
wheel diameter that closely matches the original 18"
rims with P225/50R18 Dunlops.
BTW, I finally settled on purchasing a set of 19"x8.0" TSW Estoril chrome wheels with low profile P245/40YR19 Falken FK42 tires from Bigwheels.net. The TSW wheels are identical in appearance to the picture of Petrol Nixon wheels posted below. The wheels come in at US$163/
wheel and the tires are US$205/tire. Mounting and balancing is free
As I mentioned in the other thread, the weight of the new 19"
wheel/tire combination is about 5-7 lbs greater than the OEM 18"
wheel/tire and within 2% of OEM
wheel/tire diameter; I don't think the additional weight is playing much of a factor in the feel of the suspension. The ride is somewhat "firmer" but I attribute this due to the lower profile tires. Cornering performance seems to be better with the new wider/lower profile tires. I think my choice ended up being a good balance between improved appearance and ride performance. Didn't quite have the "guts" to go all the way up to 19"x10" Estoril
rims which have a wider chrome lip or the 20"
rims for that matter
Here's a picture of the wheels I selected. In the other thread, you'll find a picture of 9 other
rims, all available in 19"