Quote Originally Posted by waynep View Post
Is your speedo/odo calibrated correctly ?
Non standard sized tyres or gearing can make it inaccurate, and therefore your fuel consumption calcs will also be out.
Best way to check it is to do a run with a GPS. If what you're reading on the speedo is within 5% of the GPS speed reading you should be OK.

Cheers.
My GPS says I'm doing 100Km/h when the speedo is indicating 104-5Km/h. I'm running 245/70 A/T's instead of the standard 235/70's, bog stock suspension and mechanicals. Bullbar, winch and spotties but other than that nothing special done to it.