4 tips to make your car fuel-efficient

Wallace Soares
6 min readJun 27, 2018

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While we are waiting for fully electric cars to be affordable(at least in Brazil they aren’t even available for selling) we will be depending a lot on gas. While I was at car school I notice some wrong tips about the mechanics of a car, and about fuel consumption. Since my childhood, I always pay too much attention to details. Every time that I watched my father driving I was paying attention how he changed gears, how he put the foot on the throttle and how he make the car fuel-efficient. And based on this I knew most of these tips from car school were wrong.

My father had a VW Golf 2013 that released a system with a lot of information on the car’s panel; one of them average consumption. I remember pretty clearly that one day that we went to the beach the car performed 17km/l with gasoline. We are talking about an engine that is 1.6L and has 110hp. So, my question was: why so many people with a 1.0L are struggling to get 10km/l? I got the answer. The part that has the most influence on fuel consumption is between the steering wheel and the driver’s seat. It’s you. So, to help you to make your car fuel-efficient I prepare these 4 tips.

Disclaimer: I assume you, as a responsible car owner, always take your car to the repair if it is required. THIS IS IMPORTANT. A car with old oil drifting inside the engine block makes the engine less efficient.

https://goo.gl/YAiBxT

To make more efficient we have to understand how it works. The above picture shows most of the movable parts inside the engine. To make it simple, this article is only concerned about the cylinder and pistons.

Every time you put the foot down in the gas pedal the pistons start to go up and down faster and this makes your car run on high RPMs(rotations per minute) making use of more fuel. That’s okay if you need it to, but it’s not ok if you are just following a car and maintaining your speed. And here we get to our first tip.

1. If you don’t need power, don’t make noises!

I often pick an Uber ride and I often see the driver making the engine scream. The driver cannot pass 40km/h because the other car in front is maintaining speed, but the Uber driver is keeping the car in 3rd gear. We can hear the engine: “PLEASE SHIFT TO FOURTH, FOR THE LOVE OF GOD!!!”.

There is another situation that is when you forget the engine has a 5th gear. Once a I pick a ride the driver reached and maintain 80km/h in FOURTH GEAR in a 1.0L car! I could hear the engine crying.

There are proper and easy ways to know whether you need to change gears. Here it is some of them:

  1. Sound. If you are hearing the engine you probably need to change.
  2. Newton’s Law(Don’t know which one). If you can’t hear the engine you can try to lift the foot out of the gas pedal. If you feel the car braking without putting the foot on the brake pedal you probably need to change gears. This is because the gear that you are is not fitted for your speed and is actually braking the car.
  3. If your car has an RPM digital or analog pointer and you pass 2750 RPMs you have to change gears.

In summary, do not listen to your driver school teacher and give power if the car is asking. You are the one to decide to give power if you need it to. For example, during an overtaking, you can use lower gears at a high speed because you need the power to complete the maneuver. Although if you are following a traffic and you know you can’t pass 50km/h you can keep 5th gear without any problem. But there is one condition, and this condition is my second tip.

2. Do not apply full gas pedal at low RPMs.

https://goo.gl/c7u79E

If you are following another car and you know that you can’t pass and you can’t speed up, you should keep the gas pedal as minimal as possible to avoid high forces on the engine block. It’s not worth it to fully press the gas pedal, reach 50km/h and take it off. You will be applying high forces to the gears, you will be injecting more fuel for nothing, and you will be applying high torque in the crankshaft for no purpose. If you need to maintain a certain speed, keep your foot in the gas pedal at 20%-30% of the total range. This is enough to maintain your car following the traffic flow and use the fuel efficiently.

But again, if you are about to make an overtaking, put lower gears(4th, or even 3rd) to reach high RPMs and high torque values to speed up and complete the maneuver.

Most of the cars reach high torque values between 4000–6000 RPMs. (https://goo.gl/uVVTHb)

3. Do not hold the car on a hill with a half clutch.

The car’s clutch is made by a super adherent material. When you press the clutch pedal you are separating the clutch disk from the engine to change gears. If you didn’t you would hear an awful noise that is basically the gears scratching themselves. The clutch disk is actually a plate that sticks to the engine to pass the engine torque to the wheels. So, if you apply half clutch pedal to hold the car in a hill you are making the engine scratch the clutch disk. This will wear out the super adherent material and make your clutch less efficient to pass the energy coming from the engine to the wheels. Plus, you will need to press the gas pedal to maintain the car in position, this will use more fuel.

4. Traffic lights should be synchronized!

Nowadays most of the traffic lights are synchronized to maintain the cars on 50km/h. By knowing your way you know if there are traffic lights and it is a waste of energy leave one traffic light with full gas power to take the next one on the green. You probably will stop again. So don’t press the full pedal to reach 60–80km/h very quick. You are not racing. You can pass through every gear with no hurry, pressing 50% tops of the gas pedal and change every time the engine reaches 2500RPMs.

Notice: If you have an automatic car the tips are pretty much the same. But in summary: do not press too much on the gas pedal. If your car’s system is good enough it will manage the RPMs for you.

These are basic and initial tips to make your car fuel-efficient, but if you start to follow these tips you will notice a better performance of your car. Without any change to drive style there is no change to fuel consumption. There is no miracle. Try and tell me your results. See? It’s easy to change little habits. You can make your car fuel-efficient without changing anything on it.

Please, if any information is wrong in this article feel free to correct me.

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