All X-Runners were access cabs, but not all access cabs were X-Runners. If yours is a double cab, it is not an X-Runner. The X-Runner also had an X cross brace to stiffen the truck frame to make it into a sport truck, and were slightly lower. They used the same 4.0L 1GR V6 as other Tacomas. Many X-Runners have a dealer installed TRD supercharger. This supercharger was installed on the stock engine, so it would not matter if it were an X-Runner, an SR5, Limited or TRD Sport or Off-Road.