Fuel efficiency – how to improve your fuel efficiency

factory design to buy How to make a car more fuel efficient

You may think that fuel efficiency is an after-thought when buying a car. However, from a financial perspective, the annual ROI between similar cars could be up to 59% when buying a more expensive car with better fuel efficiency.

Once you have bought your car, how you drive it can also have an immense impact financially.  By following just a few key steps, you could be save up to £520 a year on fuel alone, before we even consider the related improvement in safety.

Consider fuel efficiency when buying your car

Using data from “Next Green Car”, we have taken two similar cars in three different categories. For each, we have assumed that the life of the car is 100k miles over 6.5 years (using UK average of annual mileage). The fuel prices are taken from “Fuel Protest” and are accurate as of 24th January 2014.

The ROI is then calculated as being the saving in total cost divided by the additional initial cost of buying the more fuel efficient car.

In each scenario, we can clearly see the importance of fuel efficiency when buying a car:

Fuel efficiency 2


First of all, let’s have a look at small economy “city” cars. The SEAT vehicle costs £545 more. Therefore, if you were torn between the two cars, this £545 (6% of the purchase price) may be your deciding factor. However, we can see that it shouldn’t be. The difference in fuel cost is over £2000 over the course of the life of the car (based on today’s prices – we can only assume that this would increase in reality).

Therefore, the extra investment of £545 will provide an annual ROI of over 39%. You will struggle to find those kind of returns elsewhere.

And, its not just for economy cars:

Fuel efficiency 3

Fuel efficiency 4



How to make a car more fuel efficient after you buy your car

So, we have seen how much we can save by focusing on the fuel efficiency of the car. However, perhaps more importantly, is the fuel efficiency of the driver. The fuel efficiency of YOU!

There are many ways to improve your fuel efficiency when you are driving. Let’s look at some and the cost of this over the 6.5 year lifetime for the economy car we previously looked at.


Drive sensibly

The way you drive your car can have the greatest impact on your fuel efficiency. Driving in the highest gear possible is a very fuel-efficient way of driving. For example, driving at 40 mph, a vehicle will use 25 per cent more fuel in third gear than it would in fifth. Travelling at fast rates in low gears can consume up to 45% more fuel than is needed.

Another comparison is when travelling on the motorway. The optimal speed to drive is considered to be around 55mph. The faster you go beyond this speed, the worse your fuel efficiency becomes. Driving at 85mph uses approximately 25% more fuel than 70mph.

The opposite is also true. You should not accelerate too fast, and you should not brake too quickly. By being moderate in your acceleration and avoiding heavy braking, you can reduce both fuel consumption and wear and tear. Research shows that driving techniques can improve you fuel efficiency by as much as 30%. And that is not even considering the additional safety factor.

Saving per year = £380

Calculating the hourly cost of this is tricky. The average mileage per year in our calculations is 14,000 miles per year. Let’s assume that your average speed is 60mph when driving in a non-fuel efficient manner and 50mph when driving efficiently. This means over the course of a year, you will be driving for 47 hours more to be fuel-efficient.

Saving per hour = £8


Tyre pressure

It is thought that 20% of a car’s fuel consumption is used to overcome the resistance of the tyres. Therefore, having under-inflated tyres can have a huge impact on the fuel efficiency of your car. In a car, tyres under inflated by 15 psi (1 bar) lead to 6% greater fuel consumption.

Saving per year = £77

Given that pumping up your tyres once a month takes around 5 minutes, doing this each month would take a total of one hour.

Saving per hour = £77


Do not leave your vehicle idle

Leaving your car running when it is not moving is estimated to use approximately one gallon of petrol per hour. Doing this for five minutes each morning to “warm up” the car could be costing you a lot of cash. Therefore, if it is cold in the morning, scrape of the ice and clean your windscreens before turning on the engine.

Saving per year = £25

Given that pumping up your tyres once a month takes around 5 minutes, doing this each month would take a total of one hour.

Saving per hour = £6

Check your trunk

Carrying extra unnecessary weight is never a good thing for your body. It’s the same for your car. Nearly a quarter of all Britons admit that they use their boot as a permanent storage space. The US fuel economy information service states that for every 100 lbs taken out of the vehicle, the fuel economy is increased by 2%.

Let’s imagine that a de-clutter of your boot could save you 25 lbs, then this would save 0.5% of your fuel cost:

Saving per year = £7

A de-clutter probably takes about 15 minutes – an easy win!

Saving per hour = £28


Use the right motor oil

You can improve your gas mileage by up to 2% by using the manufacturer’s recommended grade of motor oil. It is simple really – use 10W-30 motor oil in an engine designed to use 10W-30 motor oil! Its not rocket science, but it is incredible the number of people who get this wrong.

Saving per year = £26

Picking the right oil probably takes about 30 seconds to check your manual and 30 seconds to find the right oil!

Saving per hour = £1560


Those last few drops…

This might sounds remarkable, but by not waiting for the pump to shut off, you could be wasting a fair amount of fuel down the drain. It is estimated that as much as a quarter of a cup can pour from the hose if you pull out too soon!

Saving per year = £5

We estimate that this takes a maximum of 3 seconds each time. This makes it quite a lucrative job to perform per hour!

Saving per hour = £115



When buying your car, fuel efficiency should be a major factor in deciding which vehicle to buy. Although a car may cost a few hundred more than an alternative, you can save thousands over its lifetime in saving cost.

Total annual ROI could be up to 60% on very similar vehicles based on their fuel efficiency.

Even more important is what you do with your car afterwards: how you drive it and how you maintain it. To paraphrase Trigger, look after your car…!

4 thoughts on “Fuel efficiency – how to improve your fuel efficiency

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  4. Excellent article. People may not realize how much small changes they make in their cars and driving can affect the costs. Hopefully the figures you provided will make them think twice and implement some of them.

    Most of us cannot think a life without a car. We can have all the advantages of owning an automobile and we can have them at a cheaper cost. From fuel to insurance there are many ways of reducing auto ownership costs.

    Also, think about the value depreciation of your car. Buying an auto is a large investment. It is my policy to buy cars when they lost large chunk of their value. This usually happens after the first year. I bought several great cars that I cannot normally afford at brand new prices. You can get a two year old car with all the extras at less than half price.
    TC recently posted…How to Reduce Car Fuel Consumption?My Profile

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