Lets see in a detail how to set UK MPG parameters for the live cost monitor. At all petrol stations in UK price is now per liter not per gallon and this price is in pence per liter. To open cost monitor settings please tap on a settings button in the cost dashboard:
In the window that opens tap on UK MPG to select it. And enter fuel price in pence per liter, miles per galon.
What about Extra per mile? The app developer sets is as (Annual insurance price + annual service cost)/(Predicted number of miles per year) - this is part of the driving cost as well I guess :)? Can be kept at zero if you drive a dad's car :). Number of passengers let you see then the cost per each commuter you want to share with.
Tap on Done and if you have some miles driven it should show the calculated cost right away. Is this right? Lets compare with http://www.fuel-economy.co.uk/calc.shtml:
This should be right then! If total cost is shown to you as zero, please see if you have some miles driven already, just drive some distance and upon every location change (approximately every 10 meters or so) cost monitor should update the cost value.