Filled up the tank today after almost 3 weeks driving.
Car's fuel consumption gauge said 59.6 mpg
ScanGauge said 57.1 mpg
Calculated (and accurate reading) 59.1 mpg
Considering we are now back to the daily grind, with most of my miles in town, 4 miles at a time and a cold start each time, I am really pleased with that.
This time I filled up with 97 RON Super Unleaded (Sainsbury's), to see if it makes a difference. It may be all in my head, but on the three miles back from the filling station the car seemed to have a bit more oomph. As I said. probably all in my head.
I added a half bottle of Redex Petrol Treatment to the full tank. That's the third tankful I have done that, but so far it doesn't appear to make any difference. After I use the other half of the bottle I think I will give it a miss.
What I did notice is that the ScanGauge, using the OBMII data, had calculated that I had driven 9 miles less than the odometer said I had. There does not appear to be any means of calibrating that.