Jeep Grand Cherokee WJ Roof Mounted Tire Carrier. You can’t fit a larger than stock spare tire in the factory compartment, our system lets you carry it on the roof. If you are running larger than stock tires, you know you can't fit a spare in the factory provided compartment. I believe a 245/75R16 (30.5") tire is the largest tire it will hold. TACTIK T-743 Wheel in Matte Black with Machined Face for 07-24 Jeep Wrangler JL, JK & Gladiator JT. $169.99. Quadratec '41 Wheel for 07-24 Jeep Wrangler JL, JK & Gladiator JT. $189.99. More choices available. Quadratec Recon Wheel for 07-24 Jeep Wrangler JL, JK & Gladiator JT. $189.99. What Rims Will Fit On Jeep Grand Cherokee? The rims size of the Jeep Grand Cherokee after 2007 is the same. After 2007, All jeep grand Cherokee models come with three rim options, and they are 17, 18, and 20 inches. But, In 2007 and before, models had two or one rim options. You’ll also get 16-inch rims in 2004 and before models. It's a 31.6" tire. Most inch-sized tires run about 1/2" under (ie: 31x10.5x15 is only 30.5" tall). So yes, it's a 32 and yes, people rub it at 4" lift. You can sort of run 265/70-16 (that's 30.6") at stock height but only if you pick a mild highway tread. If you pick an aggressive tread pattern it will rub for sure. Select Matching Wheels and Tires. FREE Mount, Balance, and Shipping! Size: 30x9.50R20. Wheel: 20x9. Jeep Grand Cherokee WJ 4WD (1999-2004) Put a chalk mark on the top of the tire and the top of the drive shaft. Put the transmission in neutral and spin the rear wheels. Count the number of times the drive shaft spins to one revolution of the tire. Example: If the drive shaft spins 3.5 times to one tire revolution, the ratio would be close to 3.55; 4 times is 4.10; 3 and 3/4 times is jeepney Discussion starter. 21 posts · Joined 2006. #1 · Apr 14, 2006. What is the biggest size tire and rim that I could fit on my WJ? I have a 2000 WJ Laredo. I've been hearing that 245/70/16R is the biggest you can run, but I've also heard and seen 255/70/16R. I was thinking 255/70/16R on a 16x7 rim with 4.25 back spacing. Here's a formula you can use to calculate your vehicle's tire diameter: (CROSS SECTION WIDTH x 0.ASPECT RATIO x 2 ÷ 25.4) + WHEEL DIAMETER = OVERALL TIRE DIAMETER. For Example: 235/45ZR-1 (235 x 0.45 x 2 ÷ 25.4) + 17 = 25.327". And here's a formula that you can use to calculate your vehicle's rear axle gear ratio: RING GEAR TOOTH COUNT ÷ W5T0s.