When the Jag sits at 70MPH the Sat Nav speed indicator is only showing 67mph.
Pretty much the same for my Audi. I think its probably the same for all cars, a built in safety margin, otherwise you could potentially go after the manufacturer if you got nicked for speeding at 33 when your speedo read 30!
I tried the same comparison on my previuos MOG (2001 4/4), and it was WAY out, one occasion I looked down and the speedo read 120! I know for sure it wasn't!
The dealer recalibrated it as its electronic I believe.
Kevin
