speedometer calibration
04-15-2006, 07:22 PM
#1
Burning Brakes
Thread Starter
speedometer calibration
I have 17 inch rims on my 1986 951, is there a way to calibrate the speedo, or is there not really a neew to do it? I just wonder how off it is? The cops here in North Atlanta are jerks, so I want to know exactly how fast i'm going.
Thanks,
Chris
Thanks,
Chris
04-15-2006, 10:57 PM
#2
Burning Brakes
Join Date: Jun 2004
Location: Livonia, Michigan
Posts: 1,011
Likes: 0
Received 0 Likes
on
0 Posts
An easy way to check your speedometer accuracy is with a stopwatch out on the highway. Time how long it takes you to go 1 mile (between the mile markers at the side of the road, not your odometer). To calculate your speed, just divide 3600/time and you get MPH. (ex: 3600/53 seconds is 67.9 mph)
Check a few different times to get an avaerage - the distance between the markers may vary a bit, but even +/- 10 feet on the mile is only like 0.2% error.
Check a few different times to get an avaerage - the distance between the markers may vary a bit, but even +/- 10 feet on the mile is only like 0.2% error.
