I'm about to purchase a 2008 4Runner SR5 which has 20" rims. The rims are really sweet (high end), but a local mechanic told me that this 4Runner is designed for only 17", and that it is too risky to go with 20" rims. I called another mechanic and he agreed. Seeing as this 4runner wasn't designed for them, I should ask the dealership to replace them with 17" rims even if they aren't as nice. Do you agree?

 

I have 20" on mine 275/55/20. If it is good 4runner and you like how it rides and don't have any mechanical issue, i think you should get it. Good luck!