GasUtil is a neat application that calculates various parameters related to fuelling a car. The main screen is composed of four tabs. The first tab - MPG - will calculate your fuel efficiency in miles per gallon once you have entered the previous and current odometer readings and the number of gallons of gas you've used. This is handy after filling your tank. The second tab will tell you how much it will cost to fill your tank, once you've entered your odometer readings, the price for gas, and your vehicle's fuel economy in MPG. The third tab calculates the number of miles driven since the last fuelling, and the final tab provides a summary of the previous tabs. This is an excellent utility for people who track their fuel economy. Unfortunately, it is not available with Metric units.