What exactly is Hypermiling? It’s a term given to that style of driving which enables you to extract maximum fuel economy from your petrol or diesel car. In some cases, hypermiling can help you exceed the claimed mileage by more than 50%.
That’s exactly what happened with the Ford Classic – where a few years ago, an automotive magazine employed hypermiling techniques to squeeze 32.38 kmpl from the car, when actual mileage is only about 20 kmpl in ideal driving conditions, and in real-world city conditions the car gives about 16 kmpl.
Yet, if you really want to stretch that last drop of fuel, there are some hypermiling techniques you can employ.
Be warned, some of the hypermiling techniques described below are DANGEROUS, and you will be putting yourself at risk. Also, if you try to hypermile in the city, you risk antagonizing a few other drivers. Start by practicing a few of these tricks, before taking on more.
Top 10 hypermiling techniques
Lighten the car
Weight is the biggest deterrent to mileage. Lighten the car of all unnecessary equipment. Remove the spare wheel, carry a tyre inflator and puncture kit instead. Remove unnecessary tools and any luggage that’s not needed. Remove roof-racks as they cause drag. If you have a MPV or SUV with removable third row seats, remove the seats you don’t need and leave them at home.
Increase tyre pressure
Increasing tyre pressure reduces the rolling resistance of the tyre and can increase mileage. It’s safe to go to about 2 psi above the recommended tyre pressure. Any more than this and you run the risk of blowouts and loss of control.
Don’t use the AC, but roll up windows
Switch off the AC in the car. Don’t use it. The AC accounts for nearly 10% of your fuel consumption. However, since you’re hypermiling, you can’t put the windows down either – not more than just an inch, just for air-circulation. If you roll down the windows it will increase wind resistance and reduce mileage.
Switch off the engine; don’t idle for more than 10 seconds
Just switching off your engine each time you come to a stop at a traffic light, can give you atleast 20% more mileage than you are used to. Don’t let the car idle for more than 10 seconds. Carmakers such as Mahindra and BMW have a start/stop (micro-hybrid) system in some of their vehicles, which works on the same principle.
Don’t rev the engine, shift to top-gear quickly
When you have to move away from a traffic light, just lightly touch the accelerator pedal, giving just enough pressure to accelerate briskly. As soon as the car gains momentum, quickly shift up to the next gear. Shift into top-gear at a speed of about 40-45 kmph and then get to 50 kmph or 60 kmph (depending on the car) and stay at that speed with very light inputs on the throttle when needed. Stay in top gear as much as possible. Avoid shifting gears often.
Don’t use the brakes, coast to a stop
Keep an eye out on the road ahead of you. Anticipate when you will need to stop and just take your foot off the accelerator. Modern engines have a fuel-overrun cut-off, which means the vehicle won’t use any fuel while decelerating. Just let the vehicle coast to a stop gently, and use brakes only for the bare minimum required.
Coasting in neutral
This is a dangerous hypermiling technique, but it can add a few kilometers to your total mileage. Once you get to a certain speed and if the road ahead is clear or there’s a slight slope, shift to neutral and let the car’s momentum carry it through for a certain distance. Of course, you’ll have less control over the vehicle, so be careful. You can cover nearly 20% of your journey this way.
Switching off and coasting
This is an extremely dangerous hypermiling technique and shouldn’t be used in the interest of safety. Get to a given vehicle speed and then press the clutch and switch off the engine. Then switch the ignition only back on, but keep the clutch pressed (with the vehicle in top-gear) and carry on coasting in this manner. The reason one needs to keep the ignition on, is that in an emergency, you can just release the clutch and the engine will fire. Also in modern cars with electronic tachometers and odometers, these will continue to function.
The biggest risk with this technique is that your power brakes and power steering won’t function with the engine off, and therefore this is not recommended. Stick to coasting in neutral with engine running at the most.
Use cruise control
In cars that have cruise control, especially in an automatic, it makes a lot of sense to use cruise control a lot. Set it for an optimum speed of 60 kmph or so and try to maintain that speeds. Each time you have to slow down, just hit “cancel” on the cruise control and let the car coast to a stop. Then accelerate gently to close to the cruise control set speed and hit “resume”. This helps increase mileage by at least 10%.
Park smartly for easy access
Park the car smartly, not in a crowded area. Preferably reverse into a parking spot so that you are facing forwards and can exit the parking lot easily. When the car is cold, trying to reverse and turn a car burns more fuel. If you can find a parking spot with a slight slope, it’s even better, as the slope will allow the car to gain momentum more easily.
Of course, all these hypermiling techniques require the car to be in great condition as well. Maintain your car according to the owner’s manual – keep the air filter clean, change engine oil regularly. You can also consider using synthetic engine oil as it is thinner and reduces friction in the engine, increasing mileage. There are a few more hypermiling tricks, but not many can be used in an Indian context. Of course, the best hypermiling technique you can use is – don’t drive, use public transport!
Calculating fuel economy
For an accurate measure of fuel economy – do the tankful to tankful method of calculating fuel economy:
- Fill the fuel tank to the brim
- Reset the odometer to zero
- Drive the car for a considerable distance
- Return to the same fuel pump and again fill tank to brim
- Note the number of kilometers driven on the odometer
- Note the number of litres it took to fill the tank from the fuel dispenser
- Calculate exact fuel economy by dividing number of kilometer travelled by the number of litres of fuel filled.
Try out some of these hypermiling techniques safely and let us know what difference in fuel economy you find with your car.