Quote: posted by col.mc on 26/01/2005 13:03:59
Quote: posted by Reflex TDI on 26/01/2005 Quite. But since he asked I have seen 145 indicated, 141 on Road Angel GPS in my old remapped PD130 with a few revs left and a bend approaching[

)]. I have not had the opportunity or inclination to max the PD150 but its bound to be similar.
Anyone know the accuracy of GPS speed readouts?
My TomTom Go usually reads out 5-10% less than my speedo.
Commercial GPS is accurate to within 15 metres or accurate to within less than 1%
[legend]Reflex TDI on 27/01/2005 17:34:11
I thought speedos were normally optimistic i.e. read slightly faster as manufacturers err on the side of caution and you think you are going faster than you are....?
Speedo's have to read optimistically - a brand new tyre and a worn one will make a difference to theh speedo reading. Also although tyres are a set size the do vary, the number of rotations per miles varies quite widely.
I think elite tyres specify on thier website the real sizes of different tyres.
J.
J.