Turbo petrol cars: How to extract the best mileage from them

Many car makers have now started offering turbocharged petrol engines with their vehicles. Turbocharged engines produce more power and torque when compared with a naturally aspirated petrol engine. The mileage of the car also does not drop much because the manufacturers reduce the engine capacity when they slap on a turbocharger. In fact, in some cases there might be a slight bump in the fuel economy of a turbocharged engine.

For instance, Hyundai Aura offers two petrol engines: there is a 1.2-litre naturally aspirated engine and a 1.0-litre turbocharged, direct injection engine. The naturally aspirated engine produces a max power output of 81.86bhp whereas the smaller displacement engine but turbocharged engine produces 118.35bhp. As we can see that slapping a turbocharger on the engine leads to higher power output. The fuel efficiency difference between the two is negligible. And, if you follow the tips below, you can enjoy the power kick while still managing to extract good fuel efficiency.

Early shifting

Start shifting early in the rev range at around 2,000 rpm, instead of using the peak torque, you will be using the good low-end torque which should be enough for daily use. When you shift early, you would not be revving the engine much which means you will be burning less fuel. Your engine will not be stressful and lower revs means more fuel efficiency.

For instance, you can drive at 40kmph in third gear and the fourth gear. If you shift to the 4th gear then your engine will be revving at a lower rpm and saving a bit of fuel.

Ride the torque curve

Torque curve is basically a graph that represents when does your peak torque kicks in. It is not necessary that you have to use all the torque everytime. Because the torque curve of petrol engines is more linear than diesel engines, you need to rev them more as the peak torque comes higher in the rev range. You do not need to wait for the peak torque to kick in, you can just keep cruising on the highways with the revs settling at just around 2,000rpm. This will help increasing the mileage as your revs will remain not increase.

For example, you are driving on an empty road in third gear. You can upshift to fourth gear as you do not need the torque to kick in. By doing so, you will save fuel as you didn’t rev your engine hard.

Coast to red lights

 

Usually what do when we start approaching a red light is brake hard. We should not do this as it is just a waste of energy. You should let go of the accelerator pedal if you know there is a red light ahead and let the engine work instead of the brakes. Most of the modern cars are now fuel-injected and they come with a fuel overrun cut-off system. This helps in burning the minimum fuel possible while engine braking. Even shifting in neutral will burn more fuel than the engine braking so it is better to let the engine do its job.

Cruise on the highways

Whenever you are driving on a highway make sure you are maintaining a steady speed. Frequent use of clutch, gear changes and throttle inputs ruin the fuel economy. Make sure you are in the highest gear possible and the revs of the engine are steady. This will help achieve the optimum efficiency of the engine and deliver the highest possible fuel economy.

For example, the best way to increase the mileage is to keep a steady speed and keep the revs minimum. If you are cruising in 4th gear at 100kmph then your revs will be higher when compared to cruising in the 6th gear at 100kmph.

Downshift to slow down

You can also downshift a gear to slow down instead of using the brakes. You would need to follow the procedure of rev-matching to use this technique. Rev-matching means that you blip the throttle so that it matches the revs of your lower gear when you downshift. You would press the clutch, shift down a gear and before letting off the clutch you need to touch the accelerator. Due to this, the engine revs will increase and you can let off the clutch. All of this needs to be done in one smooth action and you would need a lot of practice for this. However, if you are not confident with this technique then you should not use it as you will end up damaging your clutch which will be expensive to repair.

For instance, you are going 50 kmph in 4th gear at 2,200 rpm and you want to slow down. You can rev-match and shift to third gear due to which your revs will increase around 3,200 rpm. Due to this, engine braking will start happening and as the revs decrease the speed of the car will also start decreasing.

These are some of the ways through which you can save fuel and increase your fuel economy. Turbocharged engines are the future as they can produce more power even after being a smaller displacement and they are safer for the environment too. More and more companies will soon be using turbocharged fuel injection units such as Mahindra has just developed its mStallion range of engines which will soon debut in the Indian market.