Fuel Efficient Driving | How to save fuel when driving
Using fuel is part of driving a car, but using too much fuel isn’t good for anyone (except maybe oil companies). The good news is there are some simple ways to save fuel while driving. Once you know how to drive efficiently, it’ll become second nature to you.
Read on for our comprehensive guide to fuel efficient driving, and 8 ways to save fuel while driving.
What’s so great about fuel efficient driving?
There are almost no downsides to fuel efficient driving, but there are lots of upsides. Here are just some of the reasons you should be driving more fuel efficiently:
- It saves you money. If you pay for your own petrol, using less of it will be great for your bank balance.
- You fill up less. Use less fuel and you won’t be visiting the petrol station as often.
- It’s good for the environment. Using less petrol per kilometre reduces your emissions as well.
- Your engine will last longer. Most fuel efficient driving techniques are easy on your car, which keeps it in better condition for longer.
- You’ll be driving safer. The driving tips below will also make you a more careful driver, helping you avoid accidents. (This is a pretty complex relationship that’s explored in this study from Monash University, if you’re interested)
The only potential downsides of fuel efficient driving are these: You have to think a little bit more when you drive; and you’ll tend to be driving slower. Really, these are both good things that will make you a safer driver, but we thought we’d mention them.
Now, on to our 8 ways to be a fuel efficient driver.
8 ways to save fuel when driving
1. Drive slower
Driving slower is often more fuel efficient, especially at higher speeds. Driving slower also reduces the emissions your car produces. This Monash Uni study shows a passenger car uses 50% more petrol travelling at 120km/h than 88km/h. The faster car also emits twice as much carbon monoxide, 50% more hydrocarbons, and 31% more nitrogen oxides.
Slowing down will also make you a much safer driver. The World Health Organisation finds an extra 1km/h average speed means a 3% higher risk of a crash involving injury, and a 4–5% increased chance of a fatal crash.
The best way to drive slower is to give yourself lots of time to get somewhere. Leave earlier than you need to and you’ll have no need to drive fast. Also, research shows drivers who aren’t under time pressure save more fuel by driving efficiently, probably because they aren’t distracted by a clock!
2. Accelerate slower, coast when you can
Cars are at their least efficient when accelerating, especially when you’re accelerating hard. This is a particular problem in urban areas, where more time is spent accelerating from stop lights or traffic, especially when you then brake at the next set of lights.
Slowing your acceleration saves fuel by not over-revving the engine. Even in an automatic car, fast acceleration will push the revolutions per minute over the recommended levels, which reduces fuel efficiency. If you’re driving a manual car, you should be shifting up gears at around 2500 RPM for a petrol motor, or at 2000 RPM for a diesel.
The other side to this point is about coasting, where you take your foot off the accelerator and let you car travel forward without braking. When you brake you lose inertia, turning kinetic energy into heat energy. That energy comes from burning fuel, but is wasted on creating heat rather than moving your car forward.
Try to coast whenever you can, and slow down naturally when it’s safe to do so.
3. Leave a bigger gap
The 3-second gap is a key part of driving training across Australia. The idea is to drive at least 3 seconds behind the next vehicle, which gives you time to respond to changing conditions ahead.
To be a fuel efficient driver, leave an even bigger gap of five to ten seconds. When a car is close in front of you and stops quickly you’ll need to brake hard, which means you can’t coast. Leaving a bigger gap lets you slow down naturally, making the most of your car’s built up inertia. You’re also much less likely to get into an accident.
4. Maximise aerodynamics
Aerodynamic car designs are a big reason why cars have become more fuel efficient over the last few decades. Anything on the outside of a car will increase drag, which decreases your fuel efficiency. For example, roof racks can add about 5% to your total fuel consumption.
You can maximise aerodynamics with this checklist:
- Only use roof racks when necessary
- Close the windows when driving
- Transport bicycles on the back of the car instead of the roof
- Use a small trailer instead of a roof mounted box
5. Minimise idle time
Old wisdom says you use more fuel starting a car than letting it idle for a minute… it’s a myth, at least in the 21st century. Cars waste fuel idling, but they use a negligible amount of fuel starting up. Additional start ups also won’t damage your car.
So, don’t wait for your car to warm up before you start driving, and feel free to turn your car off if you’re stopped for an extended length of time, as long as it’s safe to do so.
6. Inflate your tyres
Rolling on hard tyres is a tried and tested way to increase your fuel efficiency while driving. The US Department of Energy says for every 1 psi your tyres are under-inflated, you can lose 0.2% fuel efficiency, though some research finds deflated tyres can cause up to 10% more fuel consumption.
For the most fuel efficient driving, you should keep your tyres inflated to the recommended pressure on the tyre wall. To stop the pressure dropping below that, you can over-fill the tyres by 2 or 3 psi, but there’s nothing to be gained by going higher than that.
7. Back off the air con
Air conditioning adds strain to your engine and increases fuel consumption by up to 10%. If you can get by without it, don’t use the air conditioner at all. Of course, Australia is a hot country, so sometimes cooling the car down is needed!
At lower speeds, wind down the windows and let some moving air cool down the car instead. However, once you get over about 80km/h, you’re actually better off winding the windows up and putting the air conditioning back on. The impact of you car’s aerodynamics are more important at that speed than your air conditioner.
8. Travel light
The heavier your vehicle, the more work required from your engine to move it, and the more fuel you’ll use. Here’s a checklist to make sure you’re driving with as little weight as possible:
- Take heavy items out of your car if you won’t need them on the trip (eg toolboxes or bags)
- Only take the passengers you need, and let others stay home
- If you have multiple cars, take the smaller one. It’s likely to be more fuel efficient (go by their fuel efficiency ratings if you have them)
Bonus: Drive Less
It’s a bit cheeky, but not driving at all is technically the best way to save fuel. There are lots of ways to get yourself where you need to be that don’t involve a car:
- Trains, buses, or other public transport
- Active transport, like riding a bike or walking
- Car pooling with someone else making the same trip
- Still drive, but combine two trips into one
You might even be in a position to get rid of your car altogether. GoGet Car Share helps tens of thousands of Australians live without owning a car… they use public and active transport most of the time, then use GoGet on the odd occasion they need to drive somewhere.
Drive slowly, safely, and efficiently
These 8 tips to fuel efficient driving are all simple, but may be hard to master all at once. Focus on one or two at a time, then after a few weeks you’ll use them without thinking. Then focus on one or two more.
If that’s still too complicated, the one-liner version is this: Drive slower, drive lighter, drive less. That will get you most of the way to being an incredibly fuel efficient driver, saving the environment while saving you time and money!