Hi, the stock tires on my '06 Supercharged Range Rover are 255/50/20.
I was wondering if wider tires would fit?
For example: The Supercharged Sport comes stock with 275/40/20 tires.
Will those fit?
What's the widest tire that will fit without rubbing?

 

The are 20 MM wider but that is only about an inch so I bet you are safe. The best way to tell is to go to a local shop and mount some up and then turn the wheels. Since they havea thinner sidewall they should definately be okay, go to Tirerack and check the specs on the different sizes in the brand that you want and it will tell you the exact section with, then measure the gap on your current tires and see of they will fit.