Follow up to top speed video...speedo accuracy testing with GPS!
07-07-2005, 11:54 AM
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Follow up to top speed video...speedo accuracy testing with GPS!
Special thanks to Edward Hsu for letting me borrow his GPS.
Interestingly enough, the accuracy of the speedometer with 225/40/18 Goodyear F1's is +/- 1 mph from 0-160 mph. I was surprised.
If I cruised at a steady speed and the GPS was allowed to track for a little while, the speeds were basically dead nuts on.
This was the same with my A4 1.8T. Every non Audi car I've ever owned has had an optimistic speedometer by about 5%.
<img src="http://www.nogaroblue.com/s4/speedotest1.jpg">
<img src="http://www.nogaroblue.com/s4/speedotest2.jpg">
<img src="http://www.nogaroblue.com/s4/speedotest3.jpg">
<img src="http://www.nogaroblue.com/s4/speedotest4.jpg">
Interestingly enough, the accuracy of the speedometer with 225/40/18 Goodyear F1's is +/- 1 mph from 0-160 mph. I was surprised.
If I cruised at a steady speed and the GPS was allowed to track for a little while, the speeds were basically dead nuts on.
This was the same with my A4 1.8T. Every non Audi car I've ever owned has had an optimistic speedometer by about 5%.
<img src="http://www.nogaroblue.com/s4/speedotest1.jpg">
<img src="http://www.nogaroblue.com/s4/speedotest2.jpg">
<img src="http://www.nogaroblue.com/s4/speedotest3.jpg">
<img src="http://www.nogaroblue.com/s4/speedotest4.jpg">
07-07-2005, 11:58 AM
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Nice...
I noted the same thing when driving past those radar "your speed is" signs, but at speeds in the 60's. I wouldn't have thought it would be so accurate up high. Great info, Chris!
