What he said! add - 285's will fit on 9"05GT68RSSS said:On a 18 x 9 wheel the 255/45/18 tires are the same diameter (within .1" of stock) as the 235/55/17 OE tire. Also, the 285/40/18 tire is the same dia as stock. The 255's are an inch wider than the stock tire. The 285's are two inches wider. You could go with the 255's all around, or do the 255's front and the 285's rear. Check with the tire mfgr to see if your 9" wide wheels will be compatable with the 285 tire size. All the tire mfgrs have charts with the min/max wheel widths. Most all the tire mfgrs have the 255/45/18 size, but the 285/40's are more difficult to find. I've found two: BF Goodrich T/A KDW and Toyo Proxes. I have the BFG's and like the handling and ride.
But that size will be smaller than stock and your speedometer, odometer, and tripometer will be off.nbk13nw said:I have some 275/40/18's coming in a few weeks. THat should give it an aggressive stance and not push the limits of the tire on the rim (18x9).