I don't really think, either way, weather your speedometer is 5 mph off or so, at 60 mph that your going to overwhelm the local "Barney Fife" wannabe. There are alot of other idiots out there that attract way more attention than a 70+ year old truck scooting through town at a high rate of speed, with total disregard to the posted speed limits. Well, unless we are in Mayberry... Lol... Don't worry. Someone will have the appropriate answer to your dilemma. But if they don't, you'll probably still be under the radar.😁