[lochydog]

Just been comparing my mph disaply against my Tom tom over a long journey. At 50 mph on the clock, tom says approx 47 mph. At 60 mph it's 56 on tom. i.e. approx 6% over.
So I guess the speedo's slow as I trust tom & tested him properly in my last car (a beamer). It means I should never trigger any speed cameras if i use my speedo.

So does this mean that the mpg is also showing under? or over (i.e. it thinks I'm doing more miles than I am?)

Just posted an update from my hols where it went up to 34.9. I wonder what it should be?

 

[quatroxquatro]

Similar information was posted here and I think this is why most of the on-board computer fuel consumption figures should be verified with a tank brim test. But if the speedo is wrong, is the in car odometer click we are basing our calculated distance, tank-to-tank, also wrong? I would use Tom Tom to check that too, something I will try this weekend, maybe.

 

[KugaRugby]

lochydog you've got similar resultsto me.
When doing 76mph on the speedo, my sat nav says I'm doing 70mph.

My last car was a Focus ST and that was doing 73mph at sat nav 70mph.