Tire widths
BeatingU said:
The recomended rim widths are 7 to 9 inches so they should fit since Mark VIII rims are 7" wide.
Here is a quote from LOD site:
What's the widest tire I can put on the factory wheel?
Some members have put a 255/50R16 on the factory rims, but whether or not it works seems to depend somewhat on the tire brand, model, and skill of the installer. 245/50R16's will fit more readily, though either way, they may not perform quite as well as a smaller tire, since the rule of thumb for tire/wheel sizing is rim width is greater than or equal to 80% of the section width of a tire. Using this formula, a tire with a 225 mm section width is about the biggest some people would recommend for a 7 inch wheel. The 245/50R16 is extremely close to the factory size tire in terms of circumference, but you can expect about a 3-5% difference in outside diameter, with the speedometer reading slightly higher than the actual speed. The 255/50R16 is even closer in diameter, sometime as little as half an inch difference in circumference.
I did the math and 225 is 79% of the 7" rim, 245 is 72.5% of a 7" rim.
Now I am no expert on this by any stretch but I just bought a set of Falken Ziex ZE512's P225/60R16 V-rated. I was on 1010 tires website reading consumer reports on this tire (apparently it is very well rated) and one of the consistent complaints was that the Falken had weak squiggly, noodly sidewalls. Interestingly though, every complaint regarding the sidewall issue also involved someone using a 245 or 255 wide tire on a 7" rim. So reading between the lines and using the 80% section width rule of thumb I can only assume that the complainants had no grounds to complain because they were exceeding the recommended tire width to rim ratio. But as I said I am no expert, but I do have a bit of common sense and common sense says stay witin guidlines if you want good performance. By the way, my Trailblazer EXT LT has P245/65R17 tires and I notice the sidewalls are a bit forgiving albeit it is a higher center of gravity SUV and Continental tires. Something to think about when going for wider tires though, you may have to compromise cornering performance unless you get wider rims.
