Fuel Consumption – Money Saving Tips

One of the largest costs for any driver is fuel. In the United Kingdom, the Forecourt price of a litre of fuel is made up of the product cost, the retailer mark-up (garages or supermarkets), UK Fuel Duty (currently 59.95p per litre) and Value Added Tax (VAT) at 20%.

These costs make the price of petrol and diesel in the United Kingdom among the most expensive in the world.  While it is advisable to shop around to find the lowest prices locally, there are other steps vehicle owners can take to get the most mileage out of their fuel tank.

 Vehicle Servicing and Maintenance

One of the most important steps is to get your vehicle serviced regularly.  If you don’t change the oil and continue to use the car with low fluid levels, you are likely to find that engine performance may deteriorate.

Vehicle servicing can either be an interim/basic service, a full service, Major or Manufacturer service. What is included in each type of service varies, but each service will include at a minimum the following;

  • Oil change
  • Filter change
  • Visual inspection
  • Seat Belt checks
  • Key fluid level check (brake fluid, steering fluid, anti-freeze, washer fluid)
  • Break check

Higher-end services such as a full or major service will typically include the basic checks as well as inspections of any aspect of the vehicle that goes beyond the manufacturer guidelines.

The type of service and the intervals between servicing depends on the number of miles travelled or the length of time since the last check.

As a guide, cars and vans should undergo a service at least once a year or every 10,000 to 12,000 miles.

Getting your car serviced each year – and maintaining it between each service, is money well spent. Problems are likely to be caught early on when they are cheaper to fix, and your car will have a longer life. A well-maintained car is more efficient meaning servicing is of high importance if you are to save money on fuel consumption.

Tyre Maintenance

Tyre pressure - fuel consumption

Ensuring that tyres are maintained is important for safety as well as lower fuel consumption.

Aside from tyres being more likely to blowout, the RAC claims that under-inflated tyres increases ‘rolling resistance’ resulting in the need for more energy and fuel to push the car along. The RAC claims correctly inflated tyres can improve fuel consumption by up to 2%. Check tyre pressures regularly (especially before a motorway journey).

Checking tyre pressures regularly as well as the condition of each tyre will ensure better performance when accelerating, braking and accelerating, particularly in poor weather conditions.  Stick to the recommended manufacturer advice on tyre pressure for your vehicle and take into account any additional notices on changes required when driving with a full load.

Oil Maintenance

Engine oils are not all the same. Car manufacturers and oil companies work together to agree on performance specifications with several different standards across the world. In Europe, the standards are set by the European Automobile Manufacturers’ Association (ACEA).

Oil Change - Fuel Consumption

As engine oil type varies across all makes and models, many car manufacturers develop their own engine oil specifications referring to their products in the car’s handbook. Typically these are very specialised “long life” oils designed to support long periods between services. They may also give an acceptable equivalent ACEA compliant alternative oil that can be used instead.

Most oil manufacturers claim their oil can last up to 10,000 miles before you need to change. Car manufacturers recommend an oil change every 3,000 to 3,500 miles, but this is considered conservative. It is however generally recommended to use the same oil for no more than 5,000 miles to maximise engine reliability and efficiency long term.

Ensuring that your car uses the recommended oil and that it is topped up regularly is an essential part of vehicle maintenance. Maintaining the correct level of oil is sensible as it lubricates, cools, cleans, and protects the moving parts of the engine. It not only prevents the engine from seizing up and breaking down, as a direct result it impacts upon performance and therefore fuel consumption.

Engine Carbon Cleaning

Even in well-serviced vehicles, carbon deposits may build up over time, affecting the efficiency of catalytic converters, exhaust ports and combustion chambers.

Along with other substances such as tars, gums, and varnishes, these pollutants result in reduced engine performance running at fewer miles per gallon. The long term effect of this build-up is increased emissions, higher repair costs and lower engine efficiency.

TerraClean is a patented process that uses highly refined fuel and can remove deposits from areas of the engine that some of the other processes can’t reach. The alternative is to use a water-based process (often referred to as hydrogen cleaning) which only treats the parts which air or exhaust fumes pass through.

TerraClean is applied using a specially designed cleaning unit through the fuel system so that it treats the injectors, injection pump, and fuel rail. The fuel, then injected into the cylinder, cleans the inlet manifold, EGR valve, turbo and particle filters.

TerraClean users are most likely to notice improvements that include;

  • Improved economy
  • Better cold starting
  • Quieter running
  • Smoother idle and pickup
  • Improved power
  • Improved torque
  • Less smoke from the exhaust
  • A reduction in flat spots when accelerating

They will also benefit from lower harmful emissions, less carbon build-up inside their engine and exhaust, and prolonged engine component life.

For further details on the full TerraClean process, please take a look here – TerraClean fuel system Clean.

Keep fluids topped up

The engine oil isn’t the only fluid that requires regular monitoring. The coolant, power steering fluid, transmission fluid, brake fluid, and windscreen washer fluid all need to be looked at preferably once a week. While the windscreen washer fluid obviously doesn’t affect fuel consumption, the others all can impact upon efficiency if low.

A lot of modern cars have sensors that will alert you when something is low, but it is still essential you make regular checks as this will help you notice if something is amiss like a leak.

Fuel Consumption – Getting a greater MPG while driving

Smooth driving

Your driving style can have an impact on how much petrol or diesel you use.

IAM Roadsmart (formerly known as the Institute of Advanced Motorists) offers the following advice on a technique known as eco-driving.

  • Try to keep your driving smooth. Gentle acceleration and using the highest safe gear will use less fuel.
  • Ease off the accelerator early when approaching red traffic lights so that you don’t have to come to a full stop unless necessary.
  • If possible, try to avoid peak driving times, such as during rush hours. Stopping and starting in heavy traffic requires the constant use of first gear, meaning a lot of fuel is used to get the vehicle moving again.

Eco-driving makes sense not just for fuel consumption but also for safety.

Two years ago 50 AA staff took part in an Eco-driving trial. They all drove normally for one week and then following the advice of IAM Roadsmart used Eco-driving techniques for the second week. On average the group saved 10% off their weekly fuel bills, with several saving over 25% and one individual shaving a massive 33% off their costs.

Fuel economy has changed the way of thinking across the industry. Car Manufacturers have realised the importance of fuel consumption to the frugal buyer and have implemented several fuel-saving features to modern cars. These include;

  • The addition of gear shift indicators in new cars since 2014 alerts drivers to more efficient gear use encouraging higher gears at lower speeds.
  • Start-Stop systems stop the engine when the car comes to a stop and automatically restart it to resume driving – this reduces wasted fuel from “idling”.
  • Hybrids include stop-start, regenerative braking, and larger electric motors and batteries to reduce fuel use, especially in stop-and-go driving.
  • Cylinder deactivation saves fuel by “turning off” some cylinders when they are not needed.
  • Valve Timing & Lift Technologies improve engine efficiency by optimising the flow of fuel and air into the engine for various engine speeds.

Use cruise control properly

Cruise control - fuel consumption

Cruise control on newer cars can be of benefit as it allows you to maintain a steady speed without much acceleration. One of the key factors to fuel economy is driving at a constant speed on a flat surface, and cruise control is ideal for this when travelling long distances on the motorway.

However, using it incorrectly on uneven surfaces, or leaving it on indefinitely can have a negative effect on MPG.

This is because cruise control is slower to react to gradient changes than the driver, meaning that when reaching the top of a hill – where a driver would normally take their foot off the accelerator to maintain a constant speed during descent – the cruise control will keep the power on for a little longer as it’s unable to see the gradient change ahead.

Driving in this way regularly would lead to worse fuel consumption. A lot of cars won’t allow you to use cruise control in lower gears or at speeds lower than 30 mph but if you car does bear this in mind if you are trying to save money.

Interestingly, the most fuel-efficient roads in the UK are not quiet dual carriageways or 30 mph city streets, they are motorways. This is where you can leave the car in top gear and gently cruise along, using minimal fuel.

Shift up early

How often and when you make manual gear changes in older cars can be important for fuel efficiency. When accelerating it is important to shift to a higher gear early, usually before 2,000 (diesel) and 2,500 (petrol) revs per minute (RPM). Where appropriate skipping gears is also relevant e.g. 3rd to 5th or 4th to 6th.

Stick to the limit

Driving faster uses more fuel. Driving at 70 mph will use 9% more fuel than travelling at 60 mph, and 15% more than at 50 mph. The optimal travelling speed for every make and model of vehicle is different but drive above 70 mph and the difference is noticeable.

Travelling at 80 mph for 30 minutes can use up to 25% more fuel than at 70 mph. Something to think about if you are always in a hurry.

Try to avoid prolonged idling

Running the engine at idle consumes roughly half a gallon of fuel every hour. Not only that it causes more pollution. If you are waiting for someone to get in the car for longer than two or three minutes, you are far better off switching the engine off then leaving it running.

With modern cars being more efficient nowadays, you’re likely to burn less fuel by simply turning off your engine, then restarting it when you have to move again.

For newer cars, as already mentioned, if you stop at traffic lights, take your foot off the clutch (with the gear in neutral) and the car’s stop-start system will kick-in. Leaving your foot on the clutch otherwise will keep the engine running, and it will continue to burn fuel.

Use air-condition only when necessaryAir conditioning - fuel consumption

Using air-con at low speeds increases fuel consumption, but at higher speeds, the effect is less noticeable. In warm weather open the windows when driving around town and save the air-con for when you are on the motorway. Leaving it on all the time can make quite a difference.

That said, take note that the more aerodynamic your vehicle remains, the better your car’s fuel efficiency. Keeping your windows down while driving creates more drag and wind resistance for your vehicle. If you are driving at speeds of less than 30 mph, it is usually fine to keep the windows down. However, at higher speeds, you should keep the windows up to reduce drag and improve fuel consumption.

Cut down on the use of electrics

Electrics can affect fuel consumption, although how much is still a matter of debate. Leaving the rear window heater, demister fan and headlights on can allegedly decrease the MPG of cars over five years old. While any increase in fuel consumption may be negligible, it is worthwhile considering using fewer electrics in the winter if you have an older battery.

Before Travelling

Weight loss – Empty the boot

Extra weight means extra fuel. If your car is full it places more strain on the brakes, suspension and drivetrain. This in turn will affect your car’s fuel economy and possibly the car’s emissions output. Fuel consumption is directly related to how hard the engine is working and many people forget this when they pack the car.

Don’t drive with a full tank

Less weight also applies to the amount of fuel you carry in the tank. Driving around with a full tank means the car is heavier. For older cars, the RAC suggest anything over half a tank will impact MPG, meaning you are likely to use the extra fuel quicker. Only fill up with what you need to if you want to get the best-valued return on cost per gallon.

Lose the roof rack

Removing roof racks or roof-top cargo boxes can save as much as 20% on fuel across the year. Weighing anywhere from 3 kg to 5 kg, they increase the amount of drag which in turn affects fuel consumption by up to 10% on any single journey. If they aren’t being used there is no point increasing the drag on the car.

The Energy Saving Trust claims that an empty roof rack adds 16% drag when driving at 75 mph. At the same speed a roof box adds up to 39%. Wind resistance directly affects fuel consumption. Stay aerodynamic.

 


At TerraClean, we are always looking for ways to improve car efficiency and save our clients money. If there are any other tips you can help us pass on to our customers, please get in touch, and we’ll update this guide.

In the meantime, check out the information below on how our engine and DPF cleaning service works. It could save you much more than you think.

What is a TerraClean? | TerraClean FAQs

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