Rob Young

The MPG figure displayed by the trip computer is calculated from the quantity of fuel injected on each engine stroke. Because the accuracy of this calculation will vary depending upon how you drive and the state of wear of your engine, you might find your trip computer is over or under optimistic to a degree.

To adjust the computer to compensate for known inaccuracies, follow these steps.

1. Hold in the trip computer’s stalk button.
2. Turn on the ignition. The trip computer’s display will now read “ON”. (Careful here, as setting this to “OFF” will leave you with a display of outside temperature only)
3. Release the trip computer’s stalk button.
4. Press and release the trip computer’s stalk button once only. The display will show the MPG symbol and a number representing the current offset.
5. Using the S and R buttons, set this number to the desired value.
6. Press the trip computer’s stalk button to store the value and return to normal operation.

Done! You’ll need to let the computer average out over a few hundred of miles each time you try a new value.

These steps worked for me on a Mk1.5 Ford Focus, but your mileage may vary. Couldn’t resist the awful joke.

Hope this helps!