By Dom at Reduce My Excess,
26 September 2023
5 mins read
We all have our own styles of driving, but it’s likely that some of the behaviours you’ve adopted on the road are causing you to spend more on your fuel bill than you need to. Perhaps you’re regularly stuck in stop/start traffic jams, or you have a boot filled with junk that you never get around to emptying.
Regardless of what your bad habits may be, if you want to know how to save fuel in your own vehicle or a hire car then we’ve come up with the ultimate guide to help you reduce your spend.
Driving at higher speeds increases the amount of air resistance your vehicle needs to combat. It may be tempting to rev up the engine to the maximum legal speeds once you hit the motorway, but this will be costing you more in fuel over time.
What’s more, if you maintain a lower speed then your engine will be operating at lower RPM – or revolutions per minute. This is great for your fuel economy because engines don’t need to work as hard to maintain speed and you will benefit from improved fuel efficiency.
Use cruise control
Many people may tell you that using cruise control is a great way to save on fuel, and they’re right – up to a point. If you are driving on a flat surface, such as a motorway, then cruise control helps greatly with reducing the unnecessary acceleration and deceleration you would make as you manually work to maintain your speed.
However, this doesn’t mean that cruise control is a one size fits all solution. In fact, it’s actually a bad idea to use it when you’re on roads with gradient changes – such as hills. If you’re at the top of a slope and start heading down it with cruise control on, then this feature will keep the power on for longer as it won’t be able to detect the gradient change. As a result, you will have worse fuel consumption over time.
Brake and accelerate gently
From time to time we all may need to slam on the brakes, but for the most part this behaviour should be avoided – because it wastes fuel. Instead of hitting this pedal hard – or accelerating impatiently when a traffic light finally changes – you should focus on using engine braking to coast to a stop before gently accelerating once it’s time to move again. Over time, your reduced fuel bill will convince you that the change was worth it.
Make your trips longer
If you have a number of errands to run, consider getting everything done in one trip instead of spreading the jobs over the course of a week. That’s because your engine takes time to reach the most fuel-efficient temperature, so once you’ve got it there you may as well capitalise on it.
It’s far better to stop the car for a few minutes while the engine is still warm, then hop back in and move on to the next task. The alternative is warming up an engine from scratch multiple times, which will ultimately cost you more in the long run – particularly in colder climates.
Empty your vehicle
If your boot is full of stuff you’re not using regularly, then ask yourself if you really need to be driving it around. Sure, there will be items that it’s recommended to have in your car – such as an ice scraper, spare tyre and the owner’s manual. However, if you have spent months driving around with a half empty suitcase from your summer holiday, or the boot is full of scooters and footballs that the kids never even use once they’re at the park, then it’s time to empty your vehicle and lose the dead weight which is just costing you money you don’t have to spend.
Know when to use the aircon
You may believe that using the aircon will drain your fuel no matter what, but the reality is that sometimes the aircon may be a more fuel-efficient choice than opening the windows. As we described above with when to use cruise control, there is also a good and bad time to turn the aircon on.
When you are driving through densely populated areas and going at lower speeds, having the windows open will save more fuel. However, once you’re on faster roads such as dual carriageways and motorways, it’s advisable to close your windows and switch the aircon on instead. Having the windows open on fast roads will cause additional drag, which forces the car to use more fuel as you are giving the vehicle more air resistance to tackle as it moves.
Inflate your tyres
If your tyres haven’t been inflated to the correct psi bracket then they will encounter higher rolling resistance – which essentially means that it’s harder for them to roll smoothly on the road. This means that more energy needs to be used to keep the car moving, which increases your fuel consumption over time.
Take the time to regularly check your tyre pressures, especially if you’re going on a long journey. If the light comes on your dashboard, ensure you remedy the situation right away. Driving with under-inflated tyres increases your risk of premature wear and tear or even blowing a tyre.
Get your vehicle serviced
You should regularly get your car serviced regardless, but getting professionals to check over your engine on a regular basis will ensure that your vehicle is well-maintained and any issues with the engine can be tackled before they become a real problem.
As engine parts work closely together, simple tasks such as removing sludge and corrosion will help the engine to consistently work efficiently – helping with your fuel bills as a result.
Drive when it’s quiet
Sometimes you may need to drive into the office for 9am, which means you’re going to encounter rush hour traffic. Perhaps you need to take the kids out on Saturday afternoon, in which case many more people will be out on the roads. However, where possible, it’s advisable to drive during the quietest times of the day.
That’s because there are more opportunities to use cruise control and fewer times when you will have to stop/start drive during congestion. Take the time to figure out which days and time periods during the week are quieter in your local area and capitalise on these to save on your fuel consumption.
Reverse park where possible
If you’re heading out to a car park, take the time to reverse into the space instead of simply cruising in with front bay parking. That’s because reversing out of a space will use up more fuel, and it’s better to do this manoeuvre with a warm engine.
In other words, if you’re not confident with reverse parking but want to save on your fuel bill, now might be the time to get a little practice in so that reversing in becomes a habit.
When is fuel consumption at its highest?
You will be burning the most fuel when you are accelerating, so it’s important to use this pedal gently and avoid slamming your foot down.
While it may feel exciting to suddenly speed up and zoom down the road, you will end up paying more for your petrol or diesel in the long run – so is it really worth it?
What’s most likely to waste fuel?
The answer to this question depends on your vehicle type and individual driving style, but a top reason behind wasted fuel for many drivers is not having the correct inflation level on their tyres.
Often they will not check their manufacturer guidelines for the recommended psi for their tyres, and they will end up with under-inflated tyres which is when your vehicle will use more fuel.
Ensure you are aware of the correct inflation level for your vehicle, and be sure to keep it at the higher end of the spectrum when you are carrying more weight or passengers.
This is particularly important when you are hiring a car – besides measures such as considering car hire excess insurance, other steps which should be on your mind include checking the tyres are properly inflated before heading on a long journey.
Does cruise control use more fuel?
If you are regularly on the motorway, for example if you commute to work, then using cruise control can be effective. Driving on a flat surface at a constant speed with cruise control will reduce the need to be accelerating and decelerating to manage this consistency manually. As a result, cruise control uses less fuel in these circumstances.
However, there are some situations where cruise control will use more fuel. For example, if you are going down a hill, then cruise control will not recognise the upcoming gradient change and keep the power on for longer, leading to inefficient fuel consumption.
Does car heating use fuel?
Putting the car heating on during colder weather can trigger some anxiety for those of us who want to keep our costs down. Even though we may be craving warmth inside our vehicles, we don’t want to pay the price with higher bills further down the line.
While car heating does use fuel, it isn’t a huge amount. The heater makes use of excess heat which is formed while the engine is running, so the overall amount of fuel used is minimal. The reason why your heaters will release cold air when you’re just starting your car is because the engine is cold – so wait to warm it up and you’ll be able to benefit from the warmth of your engine.
Is putting toothpaste in fuel tank a good idea?
There have been videos online depicting ‘hacks’ whereby people put toothpaste into their fuel tank and claim it saves on petrol. However, there are numerous reasons why this claim is not true.
For example, the abrasives in toothpaste can clog the fuel filter, fuel lines and fuel injectors, resulting in poor performance or engine damage. As toothpaste doesn’t burn like petrol or diesel, having it enter the combustion chamber can result in reduced engine power, increased emissions and the chance of damage to both the spark plugs and exhaust system. Damage can also be caused to the engine valves, pistons, cylinder walls and fuel pump.
In other words, putting toothpaste in your fuel tank is definitely not a good idea!
About the author
Dom has loved cars since he was five years old. He has worked as a mechanic for years, relishing the opportunity to be around vehicles and keep them in top shape.
Dom trained as a driving instructor once his daughter got her first car so he could help people to stay safe on the roads.
Now he takes every chance he can to share his knowledge of cars with the general public, focusing on vehicle maintenance and safety.