As with my daily driver:

2012 Altis 1.6E m/t
Total Mileage:15,397kms
Fuel Cost per Year: P77,862.10
Total Fuel used: 1,484.83L
Average Fuel Consumption: 10.36km/L
Service Costs: P9,620.80 (Total from 500km to 15,000km PMS at Toyota)
Total OPEX from March 2012 to March 2013: P 87,482.90
Cost per km = Php 5.68/km

I use the Android Fuel Log app to monitor my fuel consumption and expenses.