What is the fattest tire you can put on a stock 2000 grand Cherokee jeep?

For a stock 2000 Jeep Grand Cherokee, the widest tire you can typically fit without any modifications is around 31 inches in diameter and 10.5 inches in width. This usually translates to a tire size like 31x10.5R15 or 31x10.5R16, depending on your wheel size. However, it's essential to check for any potential rubbing issues, especially when turning or going over bumps, as individual vehicle conditions can vary. Always consult your owner's manual or a tire specialist for the best fit.