Frequently Asked Questions

Devices supported

General

Vehicles supported

Mounting the iPhone in a vehicle

Journey scores and weekly charts

Fuel economy readings

Gears

Acceleration, braking and smoothness

Advanced Fuel Savings meter

Maximising fuel economy

Devices supported

Does DriveGain run on all iPhones?

DriveGain runs on the iPhone 3G, 3GS and 4.

Does DriveGain run on the iPod Touch?

DriveGain runs on all iPod Touch devices - but in order to use the application you will need to buy a GPS Car Kit to mount it in. This is because the iPod Touch has no build in GPS receiver. TomTom make a GPS Car Kit for the iPod Touch.

Does DriveGain run on the iPad?

DriveGain is currently only supported on the iPad Wi-Fi + 3G model because it requires GPS which is built into this device.

Are you working on an Android version?

Not yet, but Android is most likely the next platform we will support.

General

Do you need to know a lot about cars to use the DriveGain application?

DriveGain has been designed to be as non-technical as possible. You do not need any in depth knowledge of cars in order to use it.

Vehicles supported

What type of vehicles are supported?

Today DriveGain supports automatic and manual (stick-shift) cars, or light commercial vehicles, that use either petrol (gasoline) or diesel. Hybrid and electric vehicles are not yet supported, though reasonable results may be obtained with 'mild hybrid' vehicles (such as recent BMWs with EfficientDynamics features, or Volkswagen BlueMotion models).

Mounting the iPhone in a vehicle

How should the iPhone be secured in a moving vehicle?

We strongly recommend using a iPhone car cradle. Although it is possible to secure the iPhone using other methods this can compromise road safety if the iPhone works its way loose when the vehicle is moving. It is also important that the iPhone is mounted such that that the driver does not need to move their eyes far away from looking at the road. A good mounting kit will also place the iPhone underneath the windscreen where there is better GPS reception.

Can I use GPS iPhone holder like the TomTom Car Kit?

GPS iPhone holders like the TomTom Car Kit (which comes in iPhone and iPod Touch versions) work well with DriveGain:

  • The GPS receiver in the Car Kit is more sensitive and accurate than the GPS built in to the iPhone
  • The Car Kit has a more powerful speaker that makes audio feedback given by the application easier to hear
  • The iPhone is powered and thus there is no issue of the battery running down

Journey scores and weekly charts

What is a Journey Score?

The Journey Score is worked out by comparing how much fuel you used for a journey compared to an 'ideal' efficient driver. The bigger the number the better. A score of 100% means you were as efficient as an ideal driver. A score of 50% means that you used twice the fuel an ideal diver would have used.

Why are some of my Journey Scores not counted for my best weekly score?

Not all Journey Scores count when the weekly charts are compiled. To count in the chart a journey has to be 'significant'.

Short journeys will not be counted, neither will journeys that start or stop with the vehicle moving. There are also other criteria we apply to make sure people are not 'gaming' the system and that only real journeys are counted when the charts are compiled.

When are the best weekly score positions worked out?

Your chart position in a group depends on your best Journey Score for a given week, compared to all the other members of the group.

Each week we calculate the charts like this:

  • At noon GMT every Thursday we look at the previous week's journey data
  • We count any journey that started after noon GMT on the previous Wednesday and before noon GMT on the Wednesday just gone

So if you want your journey to count for the charts, you need to make sure the app has uploaded it by noon GMT on Thursday.

The app does not always get a chance to upload journeys - it may not have had a sufficiently good data connection. If you cannot see a recent journey on the website you will need to go into the app to allow it to upload any pending journeys. About 10 seconds after the app starts up, if it has a data connection, it will start uploading any pending journeys.

Fuel economy readings

How accurate is the estimated fuel economy?

We currently believe the fuel economy we report to be within +/-20% of the actual fuel economy of the car. We have several developments in the pipeline to improve this accuracy.

Why does the fuel economy the application reports not match that shown on my car dashboard?

Your car calcuates fuel economy in a different way to DriveGain. Both calculations have some level of inaccuracy so it is rare for them to match exactly. In addition we have found that the fuel economy figures calculated by some cars can be over optimistic.

What explains the difference between the fuel economy the application reports and the actual fuel economy?

All of these factors have an effect:

  • Additional passengers or luggage - DriveGain currently assumes a single driver
  • Worn or incorrectly inflated tyres
  • Alterations to the exterior of vehicle including roof racks
  • Engine tuning or other differences from the standard vehicle specification
  • Cold starts - DriveGain currently assumes a warm engine
  • Errors in the GPS speed signal (e.g. around buildings and trees)

Gears

Why is gear choice important for fuel economy?

Where there is a choice of gear it is usually the case that a higher gear gives better fuel economy because engine speed is lower. There are exceptions though:

  • during acceleration or hill-climbing when sometimes a lower gear is better
  • driving down a significant hill when a number of gears may offer equal fuel economy

Driving in a higher gear also means there is less engine power available which it makes it easier to drive economically.

Why does DriveGain sometimes recommend a gear that is not right?

The recommendation is based on the gradient of the road. Sometimes there is a lag in calculating the gradient will result in an incorrect gear recommendation. You should always use your own judgement if a gear that DriveGain is recommending is appropriate.

Why does DriveGain sometimes recommend a lower gear when going down a hill?

It is generally considered safer to drive down a significant hill in gear and using the engine to brake the car rather than using the brake pedal. The reason for this is that on steep hills using the brakes all the way down increases brake wear and might cause them to overheat.

Why does the recommended gear sometimes move even though my speed has hardly changed?

The gear recommendation takes into account not only speed, but also your acceleration and the current road gradient. Especially with petrol engines, there is a marked difference between the most efficient gear for cruising, when a high gear is best, and the right gear for either acceleration or hill-climbing, when a low gear can be better. Sometimes, 'block-shifting' (e.g. from 5th down to 3rd for a hill, then back to 5th when the road flattens out again) can be a good technique, precisely for this reason.

Acceleration, braking and smoothness

Why does the estimated fuel economy slowly tick down when stationary?

If the app is left running and the vehicle is stationary, DriveGain assumes the engine is still running. In terms of fuel economy no distance is being travelled but fuel is still being consumed so the fuel economy slowly reduces. In order to avoid this waste of fuel, most manufacturers recommend switching the engine off if you would be idling for more than about 30 seconds.

On the Advanced Fuel Savings meter why does the acceleration and braking meter turn red when braking?

Braking indirectly wastes fuel. When you brake you turn the energy from the motion of your car into heat - and this energy is lost. Every time you brake you are missing an opportunity to save fuel by lifting off the accelerator earlier.

DriveGain encourages drivers to minimise braking by anticipating the road ahead to reduce unnecessary braking and acceleration.

How am I supposed to slow down without braking?

Rather than braking to slow down:

  • Anticipate where you are going to need to slow down
  • At a point much earlier than you would normally brake, lift off the throttle
  • Keep the car in as high a gear as possible as it coasts to a stop
  • Be prepared to use the brakes if you have misjudged the timing of lifting off the throttle

This is one of the more difficult driving techniques to master. Learning when to lift off the accelerator requires quite a lot of practice. Remember that other road users may not be expecting you to slow down quite so early so take into account the other drivers around you. Road safety overrides all other considerations when driving.

Advanced Fuel Savings meter

What is the smoothness reading?

Smoothness shows how well the driver is maintaining a constant speed during the last few minutes of driving. If you are driving smoothly then you will be minimising the amount of braking and acceleration which will greatly improve you fuel efficiency.

Aggressive driving styles that use a lot of acceleration and braking will see a lower smoothness rating than driving styles that minimise unnecessary speed variations.

Driving on an open road will afford more opportunities for smooth driving than urban driving where inevitably drivers must navigate traffic and road junctions. A driver on an open road maintaining a constant speed can expect a 100% smoothness rating. While driving in an urban environment a lower smoothness rating can be expected.

Increasing your smoothness rating when driving in urban areas by anticipating where you will need to next come to a stop will significantly reduce fuel consumption with very little impact on journey time.

Why does the green zone on the speed slider change?

The green zone on the meter shows the ideal range of speeds you should be aiming for. These optimal speeds are changed by the road gradient so you will see the green zones changing as you go up and down hills.

Why does the speed meter turn red at relatively low speeds?

Whilst going too fast is bad for fuel economy - so is going too slowly.

Usually when you use lower gears you use more fuel - so the most fuel efficient speed to travel at is normally the slowest you can go in top gear.

Maximising fuel economy

Can vehicle choice affect fuel economy?

When choosing a vehicle for fuel economy the following factors are important:

  • The heavier the car the worse the fuel economy. When accelerating the vehicle more energy is required. When cruising there are energy losses in the car mechanics which increase as the vehicle weight increases.
  • Aerodynamic drag has a big effect on fuel economy at higher speeds - bigger 'boxy' cars tend to be much less aerodynamically efficient.
  • An overpowered car has a lot of potential to accelerate quickly which can be a major source of poor fuel economy.
  • An underpowered car will be difficult to drive in higher gears and so will be less efficient than a car which has an appropriate level of engine power.
  • Diesel fuel has more energy per litre than petrol (gasoline) - so a litre of diesel will take you further. In addition Diesel engines tend to be more efficient.

Does DriveGain support advanced Efficient Driving techniques?

Advanced techniques such as 'pulse and glide' and speed management over hills can be used when running DriveGain. Drivers using these techniques correctly should find that DriveGain recognises the associated fuel economy benefits.