Suggested tire size on tire rack is 285/45/22 for 22 inch rims for the Tahoe, but a 305/40/22 is nearly identical to the overall size of the stock tires. Any big diff aside from the slow spedo and slightly larger side wall if you go with the 285s?

 

Speaking from experience, I would go with the 285s. I just put the 305s on my 07 LTZ and have rubbing issues in both the front & rear fender well liners. I've also read elsewhere in the forums that the 285s ride better.

 

Interpreting the numbers:

285 vs. 305 -- this is the width of the tire in millimeters
45 vs. 40 -- height from the top of the rim to the top of the tire (sidewall height)
22 -- size of the rim

The305/40/22 will be 20mm (a little over3/4")wider and 5mm (slightly less than 1/4") taller. Both of these stats could be the sourceof rubbing reported by many people.

 

The middle number (sidewall height)is not a size, it's a percentage of the first number (width). In the 285 tire, the height is 45% of 285 or 128.25 mm. In the 305 tire, the height is 40% of 305, or 122mm, for a difference of 6.25 mm. Still only about a quarter inch difference, but the overallheight is much different.

 

Here's a site that I found with a tire size comparison tool: http://www.1010tires.com/TireSizeCalculator.asp

Their comparison:


[IMG]local://upfiles/5943/841609C41904434CB31F4442AE9A0988.gif[/IMG]

 

You won't rub if your offset is correct. People have rubbing issues because they have an incorrect offset. I have the 305's with a 9.5" wide wheel at +30 offset. Perfect with no rubbing at all.

 

I looked at that site. As I said, the 305s will give the same speedo rating as the stock tires. A little extra side wall would be nice, but only 1/4" isn't a big diff. I think I"ll just stick to the 305s.

 

Update from my 2007 post. After replacing my 305 45 22 Falken Ziex STZ04 with the same tire, but this time with a 40 series, the rubbing has mostly gone away. Even with some modest trimming of the fender well liners to accommodate the 45s, I had a substantial amount of rubbing in the rears when entering and exiting driveways. Now with the 40 series, it is very minimal. It's strange that the fitment guys at Falken told me the the 45s were the correct choice when every other source I've been able to find since then has indicated that the 40s are correct as they are almost identical in circumference to the stock 20s.

Although a car always rides better with new rubber, I honestly think that the 40s feel smoother and have less high speed shake than the 45's. Plus, I never thought the 45's looked quite right.

 

Did you try using a heat gun to reshape the liners before trimming?