DriveGain has released a free iPhone application, called CarEconomy, that shows your average fuel economy as you drive.
CarEconomy, which works on the iPhone 3G, 3GS and 4, doesn’t need any user input apart from selecting your car model from a list. Once you’re driving the app can display fuel usage in MPG (US or UK gallons), l/100km, l/100miles or km/l.
The basic download comes with a simple average fuel consumption figure, but an optional upgrade adds an instantaneous fuel economy meter that shows how much fuel you are using at any given moment.
The company also has the paid-for DriveGain app that helps you save fuel while you are driving by providing visual and audio feedback on what changes you can make to your driving style to help you save more fuel.
The display has an acceleration and braking meter that shows how fuel efficient current braking and acceleration is. A speed meter is colour coded to show fuel efficiency. And a Smoothness reading shows how smoothly you have been driving over the last few minutes - the higher the number the better
The company maintains that using DriveGain should save you, on average, £170 per year in the UK/$205 per year in the US. On this basis, for an average driver the application will pay for itself within 2 weeks.
I’m not sure how useful the basic free version would be. The app would make you aware of fuel consumption but not much more. You would need to upgrade to the ‘instantaneous’ meter version to get some real feedback on driving – although is it close enough to real time to be meaningful?
The paid for, DriveGain app may well be worth the investment, though - cost is not given, but based on the expected savings it must be c£6.50/$7.90. As one who tries to practice ‘green’ driving it takes a while to get used to it. The app would help, but you wouldn’t need it for more than a few months.