N o GPS. And keep in mind, I drive a truck for a living and doing this could end my career. But on one fine day with 2 mile visability on a 55 mph road I had it up tp 135. seemed to have plenty left but I was losing sight distance and felt that was enough for the day. When people ask how fast I've had it up to I tell them 80 mph... over the speed limit. Sure would like to see 150 someday though.