Yes, I would have to agree with SubRammer. I am currently driving my 09 1500 Crew Cab TRX in Germany. Yes on the Autobahn. I drive low-speed, high-speed, hilly, flat terrain. When I had my truck in Texas I ran 89. Now in Germany the Octane levels here are 95 and 98, which I learned is equal to 91 and 93 respectively. I have used both 95(91) and 98(93) and have not noticed any difference in performance or noticed any pinging. I have however noticed much better gas mileage. about 4 MPG average gain, though that could be the terrain not necessarily the octane. Just thought I would put that out there.