Trip trap

I CAN'T tell you how accurate trip computers are, but I am cautious about their accuracy. Nothing is 100 per cent accurate. I have had some very suspicious results from trip computers. For instance, I recently tested a new Falcon XR8 ute and the trip computer told me the average fuel consumption was 16.5 litres/100km in the week I drove it. I next tested an FPV Pursuit that had a more powerful version of the same V8, but the indicated fuel consumption was 12.5 litres/100km in similar driving conditions. Granted there were some inaccuracies in what I was doing, but I can't believe there was a difference of 4 litres/100km. I wasn't surprised the XR8 was a gas-guzzler, but I was very surprised at the economy of the Pursuit. It made me suspicious of trip-computer readings.