10 mph" tolarance " is pretty generous, many depts. only allow about 5mph from my experience, especially on local roads..
I checked my speedo with my old magellan (cheapo) gps, found it to be right on up to about 45 mph, and about 1mph off(fast) at 65 mph.. not bad.. it seems to get progressively less accurate the fast i go, but no measureable difference between 65 and 80mph..im guessing its probably about 1.5 mph off at that point, but cant tell without much more accurate equipment.. checking the speedo (and the other gauges if possible) is one of the first things i do when i get a "new to me" vehicle.. ive had a few cars that had gauges that were way off..
ive no plans for any radical tire size changes, but if i did, id definatly want the recalibration. running mental recalibration equasions while driving makes it more stressfull and takes concentration away from things like avoiding idiots on the road..
Maverick
99' Ebony VX sold...