speedo calibration

[spice]

got a new jag xkr,topped it out at 160 mph stil no limiter cutting in,even when the speedo reads 110 mph it doesent seem that fast compared with other traffic,is this a ford gremlin?

[clositintelctual]

check it by finding a measured mile on a motorway near you, these are shown by a small round sign in red about 10 inches in diameter, each 1/4 of a mile there is another with a 1/4 segment in yellow and so on untill you reach the mile - all yellow. Phone your nearest traffic police base and they will tell you where the nearest one is. you then need a stop watch and just drive the measured mile at 60 MPH, time yourself then calculate your actual speed. Alternatively find an active speed camera and drive through it at 60 MPH you will end up with a very accurate recording of youre speed.

[GreenV8S]

quote:
check it by finding a measured mile on a motorway near you, these are shown by a small round sign in red about 10 inches in diameter, each 1/4 of a mile there is another with a 1/4 segment in yellow and so on untill you reach the mile - all yellow. Phone your nearest traffic police base and they will tell you where the nearest one is. you then need a stop watch and just drive the measured mile at 60 MPH, time yourself then calculate your actual speed. Alternatively find an active speed camera and drive through it at 60 MPH you will end up with a very accurate recording of youre speed.

Alternatively, just use the 100m marker posts which are all along all motorways.

[nonegreen]

Borrow a GPS like Garmin or similar. they will give you a comparative speed reading to within 1 or 2 %. Best to do this at a constant 60 70 mph. The GPS will update frequently enough to give you a good idea if the speedo is out or not.