Will P275/55R20 tires replace P275/50R20 tires on my 2011 Mercedes Benz Gl350

As long as they are all the same it should be fine however the vehicle is programmed to the factory spec tires so you will see a difference in how mileage is recorded and technically the shift points will be affected as well. In this case your ride quality will suffer too, because you are reducing the sidewall. Are you doing this for looks? Alex

Just don't do it, for all the concerns Alex brought up. Too many bad things can and will happen.