On Friday, October 16, 2009 6:26 PM [GMT+1=CET], Captain Beeky <[email protected]> tweaked the Babbage-Engine to tell us: > On 16 Oct 2009, at 16:58, Brian on Harnser wrote: > >> roger_millin wrote on 16/10/2009 : >>> Brian wrote: >>>> I bought a Tomtom and this shows that my speedo reeds 3mph high >>>> from 30 >>>> all through the range. >>> >>> Because the legislation on motor manufacturers enforces speedo >>> calibration >>> that is allowed plus 10% but minus 0% (IIRC) so the manufacturers >>> tend to err >>> on the upper side to ensure that their customers don't >>> inadvertently exceed >>> the speed limits. In your case 3mph in 30mph is spot on the 10%. >>> Roger >>> >> But 3 MPH at 70 isn't. I've never been any faster than that > > Yeah but it is "within" the +10% tolerance. I'd always assumed a 10% > tolerance would be linear up and down the speed range, which it > probably would be with a mechanical speedo. I guess with the > electrickery they can do anything.
Indeed. The last two motorcars I've hired in the US have been spot-on when measured against GPS at illegal mph and electromagical timing at Make Your Mother Cry mph. -- Dave Larrington <http://www.legslarry.beerdrinkers.co.uk> Now available in Exmouth.
