Hi guys.

I reset all my trip settings at my last diesel fill to see how accurate DIS was.

Done the usual calculation (litres filled divided by 4.546 to get the gallons and divid the mileage by the gallons) and found that I was averaging 43.5MPG.

DIS over the same trip however calculated my average of 47.9MPG.

What do you think is at fault?

The odometer or the DIS?

I would have thought they work together?

My tyre size is 225/45/18. This isn't worlds apart from the rolling radius of the original 235/45/17 tyres so I don't think this would adversly affect the odometer readings.

Any thoughts?