How to Save Petrol
With the ever rising prices of petrol, it’s becoming increasingly essential to look at ways of saving money by means of Eco driving.
Simple changes to your driving techniques allows smart Eco driving to save not only fuel but no loss of time in reaching your destination.
This how to save petrol section will provide information for Eco driving; that will not only save you petrol or diesel, but provide a safer driving experience and reduce the amount of CO2 emissions released. Below are 16 top tips on saving money on petrol or diesel fuel expenses.
1. Driving at high speed
Air resistance is a significant factor when driving at speed. The faster you go, the higher the resistance meaning more energy is needed. The energy needed to accelerate your car from 10 mph to 20 mph is minimal as the only energy required is to move the weight of the car with slight air resistance.
Motorway and dual carriageway speeds of 70 mph account for 40% of the cars energy being used due to air resistance. This percentage increases rapidly with even the slightest gain in speed. To give an indication of how air resistance decreases fuel efficiency, driving at 70 mph compared to 60 mph uses 9% more fuel, driving at 70 mph compared to 50 mph uses 15% more fuel. Just an extra 10 mph by driving at 80 mph compared to the legal speed limit of 70 mph can use a staggering 25% more petrol.
Let’s say you have a 60 mile trip to make on a 70 mph dual carriageway or motorway. Traveling at over the speed limit of 80 mph will save you only around 6 minutes compared to driving at 70 mph. Considering you can use 25% more petrol at 80 mph, it really doesn’t seem worth it.
2. Reading the road
Your engine simply pulling the weight of the car in urban cities and towns is now the factor and not so much air resistance. Reading the road ahead effectively can save huge amounts of petrol.
As we all know, there are often queues of traffic at traffic lights, junctions, roundabouts etc. Looking well ahead whilst driving and anticipating a stop is beneficial. Ease off the accelerator well before you reach the traffic queue and apply the brakes gently as you get closer. Driving in such a way, by keeping your foot off the accelerator and using the cars momentum uses no petrol. If you compare this to keeping the accelerator on and braking harshly when you reach the queue, you can easily save over 5% of petrol.
Driving using this technique also reduces brake and disc wear significantly. Depending on your vehicle, a new set of brakes and discs can cost easily in excess of £300.
Tailgating is not only dangerous and pointless, but it also increases petrol consumption, wear and surface damage to the car. Driving too close to the car in front involves constant braking and accelerating as you need to react quickly to what the car in front is doing. Remaining back at a safe distance allows you to slow down gently by easing off the accelerator and with less need to use the brakes.
Keeping a safe distance often means you lose less speed due to the need to brake less, saving you fuel and wear on the brakes. Other than tailgating being dangerous due to reduced reaction times, it also increases the possibility of windscreen and bonnet chips caused by small stones thrown up by the car in front. See tailgating for further information on the dangers, laws and penalties for tailgating.
4. Fuel efficient gear changing
Driving in a higher gear means higher revs, which in turn means higher petrol consumption. Aim to change up a gear at around 2,000 rpm for a diesel and 2,500 for a petrol. Fuel efficient gear changing such as this can use up to 15% less fuel. Driving around town in a 30 mph zone in most modern cars can be achieved in 4th gear.
5. Reducing the weight of your car
The greater the weight of your car, the more work the engine needs to do. Removing any none essential items from your car such as child seats if not in use and any items from your boot will help to save petrol.
6. Car Aerodynamics
The easier your car can move through air resistance the less fuel is used. Roof-rack and roof storage boxes add to air resistance significantly, especially at high speeds. Remove any such items if not in use.
Coasting is a method believed to save petrol by free-wheeling by use of keeping the clutch depressed for long periods or keeping the gears in neutral whilst the car is still moving. Coasting is in fact dangerous as you lose the ability to accelerate if a potentially dangerous situation arises. Coasting also reduces the effect of braking, which is again dangerous but also increases brake wear.
When you release your foot from the accelerator, modern cars don’t use any petrol. The ECU or Electronic Control Unit cuts fuel to the engine when your foot is remove off the accelerator. Depressing the clutch or putting the gears into neutral puts the engine in a ‘tick-over’ state as though you were stationary with the engine running. Therefor coasting uses more petrol in modern cars. Further information on coasting can be obtained from ‘What is coasting‘.
8. In-car controls
Air conditioning systems increase fuel consumption. If you are driving around town, turn off the air-con and open the windows. At higher speeds air resistance will become a factor by keeping your windows open and the air-con should be used in these situations.
Any extra electrical load effectively increases fuel consumption. The biggest electrical users are the rear window heater / demister, headlights and fans and heaters. Most cars recycle the heat from the engine making the fans the biggest electrical drain. Cars fitted with instant heaters will require significantly more power.
9. Turn the car off
If it looks like you will be stuck in a queue of traffic for more than a minute or two, switch off. However, starting a car consumes a certain amount of fuel, approximately the same amount as though you were idling for 1 minute. Turning the car off for a short stop of under 1 minute may consume more petrol than if you were to leave it running. Modern cars that utilize start/stop technology employ a system that uses less fuel on start-up.
10. Moving off
Modern cars don’t need to warm up for long periods of time when you start them in the morning. After 30 seconds or so, move off. Colder engines are however less efficient than warm engines. It can take several miles before your engine is at its most fuel efficient. When the engine is cold, don’t push your engine too hard so as to save on petrol.
11. Taking a short eco driving course to save petrol
Taking a Eco driving course will enable you to improve your driving, making you a safer and more confident driver. It will of course teach you the correct method for Eco driving and potentially save you a fortune in petrol expenses.
You don’t need to specifically look for a Eco driving course. You can simply contact a driving instructor and tell them you wish to improve your driving with a view to saving fuel costs. Even a one-off 2 hour lesson will benefit you immensely.
12. Choose your car carefully
Your cars fuel type is important. Although diesel cars are more economical, they often cost more to purchase when compared to a similar petrol version. Plus diesel costs more at the fuel pump. A diesel car may only benefit financially if you cover high mileage each year. For further information on deciding whether a petrol or diesel is right for you, see petrol or diesel, which is best for further information.
Car maintenance can save petrol
A few simple car maintenance checks can over a short amount of time save a significant amount of petrol.
13. Check tyre pressure
Under-inflated tyres increase drag. Have you ever tried riding a bicycle with under-inflated tyres? How much harder is it to ride? A car is no different. The engine will need to work much harder with under-inflated tyres, therefore using more petrol. Check your cars manual for details of the correct tyre pressure or ask at a tyre specialist garage.
15. Check your engine oil
If your engine is running low on oil, it may increase friction within the engine on the moving metal parts. More friction means the engine needs to work harder to accomplish the same level of performance you are accustomed to. Again, this leads to more petrol consumption. Check your engine oil level at least once a week or more if you gain high mileage. Using the correct grade of oil will also enable your engine to run more efficiently.
16. Car servicing
Car servicing is something we all like to avoid if possible. As that oil gets constantly churned around inside a hot engine, it degrades over time providing less lubrication to the engine parts. Less lubrication means more friction and again more petrol used due to the engine working harder.
As engines work, they also produce small particles of metal. Over time, more and more of these particles are generated causing more friction to the engine parts. The engine filter gathers these small particles but lack of frequent servicing means the filter can no longer work efficiently.
A basic service, even if done by yourself, will provide the engine with clean oil and filter allowing it to run smoother and be much more fuel efficient. Significant savings can be made by servicing your own car. See How to service a car for more information.
Extra tips for saving petrol
There are a few obvious tips that can be used for reducing petrol consumption that can easily be forgotten.
Driving in the snow
In the cold winter months when it’s snowing, before moving off in the morning, remove all the snow that has settled on the car. All this snow increases the weight of the car and increases air resistance when driving. Also the police aren’t too happy with drivers leaving snow on their car as it can be hazardous for vehicles behind when driving.
Before making a journey, plan ahead to reduce the chances of coming into congested areas, especially at busy periods of the day.
If you have work colleagues that live close by, take it in turns to drive to work. This way you will be halving your petrol expenses for work travel. Another example could be if you have friends that live close by, share a car when doing your grocery shopping.