App: DriveGain

By: DriveGain Ltd

Price: £3.99

Available on: iPhone, iPod touch and iPad.

What is it?

DriveGain is an app that helps you save fuel as you drive by recommending what gear you should be in and how to save fuel as a result.

Who is it by?

DriveGain was co-founded by Simon East and Dr Phil Dixon in December 2008. East was part of the executive team that transformed Psion's software group into Symbian and founded the mobile-photo uploading company Cognima (later to become ShoZu). Dixon has a PhD in Vehicle Dynamics Control and prior to DriveGain was part of the Renault Formula One team, as a vehicle performance engineer on the chassis that won two World Championships for Fernando Alonso.

What does it promise?

"DriveGain is an application that helps you save fuel while you are driving. Saving fuel not only saves you money – it reduces the amount of CO2 you emit and allows you to travel further before needing to fill up. As you drive, the application gives you visual and audio feedback on what changes you can make to your driving style to help you save more fuel."

How does it work?

Input what car you have and the app will use the iPhone's GPS and accelerator to compute how fast you are going, whether you are accelerating too quickly, how you are braking, and average speeds.

When I trialled it, I launched the app ahead of a 25-minute trip involving city traffic and a dual carriageway. There was an initial wobble when the app told me I was at a decent cruising speed while, at the time, I was merely edging close to 30mph in third gear, which made me wonder how accurate it is. But after that the app's messages seemed more reliable.

I have a habit of slamming my car (a 1996 Volkswagen Golf) into fifth gear as soon as I can, which I probably learned from my father, a great fuel-conserver; it means I often find myself absently chugging up a hill in fifth gear. The app seemed to notice this and told me at one point to consider using fourth gear instead of fifth when I was travelling at 40mph – it was right.

One thing the app cannot do is see the road in front of you. This meant that often, just as I would need to hit the brakes due to traffic or lights ahead, the app would tell me to accelerate and plop the car into fourth gear. With that in mind, it's worth noting that drivers should never blindly follow the app's suggestions without first thinking what action is safe for them to perform.

When I cranked up the speed on the dual carriageway, the app seemed to prove its worth by telling me how much fuel I was burning, checking I was in fifth gear and maintaining a sensible cruising speed. This echoes the experience of an iTunes reviewer, who said the app worked "convincingly" for them on dual carriageways but not on town traffic.

Around 30 seconds after you have come to a halt, the app gives you a summary of your averages and totals, offering an illuminating look at how much petrol you've burnt and, more importantly, how much it has cost you.

Is it easy to use?

Yes. The fact that it offers audio support is crucial, as it can be difficult to view the screen while driving – even if it's dashboard-mounted – and it would be hazardous to do so. These audio messages are accompanied by a simple, segmented screen which make the app particularly user-friendly.

Is it fun?

Driving nerds and serious money-savers will enjoy it. The "green zones" (areas you should try and keep within for the best fuel conservation) will please thrifty drivers.

Is it pretty?

Heavy on the use of black and white, the app possesses a sophisticated, monochrome gravitas punctuated by bursts of colour that will please many. It looks better on your dashboard than one of those turtle-like air fresheners, is designed well, and has impressive functionality. But if you dashboard-mount it alongside a satnav, it can clutter up your driving experience – or make you look like a taxi driver.

Should you download it?

I can't give this a free pass because it costs £3.99 which, while little more than the value of a pint in a metropolitan bar, is a hefty outlay in app terms. It therefore should not be downloaded without serious thought.

DriveGain's creators claim the app should save you, on average, £170 per year in the UK, $205 in the US, and €175 in Europe. While I have not had time to test that claim, the app did seem to spot how some of my driving quirks were costing me more in fuel and £3.99 could be a small price to pay for a constant reminder to watch how I'm driving.

But some app-users on iTunes report incorrect gear-changing instructions, inaccurate (or at least differing) figures given for miles-per-gallon at the end of journeys, and poor driving instructions. Of course, other users call it "a great idea" and they are glad they bought it.

It's worth noting that the app works for petrol and diesel cars as well as automatics, but does not yet support electric or hybrid vehicles.