Ok I was only planning on going up to a 1.5" anyway, but thanks for the info!You can do a 1.5" on the 06 Nytro. But that is the max without removing the front cooler protectors. If you remove those you can go up to 1.75". 2" you would risk contacting the front cooler, or coming in contact with the exhaust system. This all assumes you have removed the tunnel protectors.