The aim of this article is to introduce the reader to the basics of car fuel efficiency. On the surface, it seems that fuel efficiency is a simple topic. The amount of fuel a car consumes majorly hinges on one thing – how much and how hard does the engine work? The amount of fuel consumed per gallon is directly proportional to the amount of work to be done by the car’s engine.
However, as we shall see, how hard the engine has to work itself depends on a lot of factors – the A.C., the weight of the vehicle, air filters, tire pressure, resistance from multiple things, and what not.
Tire Pressure- Remember to make sure that the car tires are always inflated to the correct pressure. Lower pressure will increase rolling friction against the ground, resulting in more work for the engine to propel the car, which will ultimately lead to more fuel consumption. Check the pressure at least monthly, if not weekly. There are apps available that connect to your car and keep you informed about your car’s tire pressure.
Note the Weight- It’s evident that the more weight your engine has to carry, the more power it needs and the more fuel it uses. Hence your car should be as light as possible optimize for fuel consumption.
Which means that if you’ve got stuff in your car trunk that you’ve been carrying around without much thought, rethink if you really need to lug those items around or not. If you can do without them, put them aside for now.
Also, additional accessories added to the car will decrease fuel performance, not only due to the additional weight, but also by increasing the aerodynamic drag (i.e. air resistance).
Stick to the recommended fuel & motor oil- The car manufacturer probably has a recommended fuel type for the car, and for a good reason. The manufacturer has already tested for the car’s optimal performance using various types of fuels, and therefore it makes sense to stick to what they ask you to use. With the same logic, it is also considered wise to only use the motor oils recommended by the car maker. Although 3rd party motor oils may work in some cases, they aren’t always well tested for a specific type of vehicle, unlike the product the car manufacturer will recommend.
Avoid Idling- Idling refers to when one keeps the engine running while the car is stationary – like stopping at a red light. Thing is, idling uses up fuel but your car isn’t going anywhere, it’s just 0 miles per gallon, always. So it’s always better to turn off the engine rather than idling. Instead of ‘revving up’ the engine in cold weather, a better practice is to drive very slowly until the engine is gradually warmed up.
Replace the Air filter- The air filter prevents harmful foreign substances from entering and damaging the engine. Always replace this according to the schedule specified by the car manufacturer because this is one of the simplest things to do with regards to fuel economy.
A clogged air filter impedes the engine’s ability to draw in air, and hence the engine has to work harder.
Prudent Air Conditioner use- In general, car A.Cs need engine power to operate, which translates to lower fuel economy while the A.C is on. But hold on, this one’s not that simple.
If you use the A.C and turn up the windows, the power drawn by the A.C pushes up fuel consumption. However, if you roll down the windows and turn off the A.C, you push up fuel consumption because of a higher drag (air resistance) created with the windows being down.
So, it’s essentially a trade-off – which alternative consumes more fuel?
It is believed that in city traffic – stop and go types, it’s better to turn off the A.C and keep the windows open.
But when cruising at higher speeds, it’s better to keep the windows shut and the A.C on, because the drag at higher speeds is obviously more and impacts fuel efficiency more than the A.C would.
Constant Speed is good, sudden braking and Accelerating are bad- With braking, one is wasting the energy generated by the fuel that has already been burnt. When it comes to acceleration, it takes more energy and fuel to suddenly accelerate than it does to drift at a constant speed. With sudden bursts of acceleration, the engine has to exert force against air and ground resistance, and also on the car to push it to a certain speed. With a constant speed, the engine doesn’t have to really work more to move the car forward, because it’s already at a certain speed. For the same reason, it’s often considered good practice to use the Cruise Control option on your car.
Following these tips should easily result in greater fuel economy for your car and therefore more savings for you.