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What is a good MPG? Average car MPG explained

Miles per gallon (MPG) breaks down how efficient your car is to drive and helps work out running costs 

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MPG meaning - what does 'MPG' stand for?

‘MPG’ stands for miles per gallon and is a measurement of how many miles your car can travel per gallon of petrol or diesel that it uses.

Cars with good MPG figures can travel long distances on smaller amounts of fuel, meaning they’re an efficient choice and keep running costs low.

You’ll usually find that diesel cars are the most fuel-efficient and have the best MPG ratings, but choosing a hybrid is another great way to cut back on fuel costs.

What is a good MPG?

A good MPG is one that allows you to cover a good distance on the least amount of fuel.

A good fuel consumption figure for a used car is around 40-60mpg. Cars that can achieve 40mpg are likely to help you keep fuel costs low, and anything above this is even more impressive.

For example, the Volkswagen up! is capable of more than 54mpg in the petrol models, while the Toyota Prius can achieve up to 67.3mpg.

It’s important to consider the type of car as well, as this can have an impact on what is considered a good MPG figure.

Large SUVs are going to use more fuel to get moving than a small hatchback, so bear this in mind when comparing MPG statistics.

For example, the diesel BMW X7 can achieve just under 37mpg, which may seem low in comparison to the Prius or up!, but there’s a huge size difference between the cars that means the seven-seater SUV will always need to use more fuel.

How many miles to the gallon does my car cover?

Before you purchase a car, you should be able to find the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) fuel economy rating, and this will give you a best-case scenario of how you can expect your car to perform for efficiency.

Older cars might not have a WLTP figure and instead use the New European Driving Cycle (NEDC).

You can also calculate your own MPG once you’ve purchased a car to get an estimate of how your driving habits and daily journeys differ from the WLTP figure.

How to calculate MPG

  1. The next time you fill up your tank to the top, take the number of litres it took to fill and multiply this by 0.219 to convert the figure into gallons

  2. Subtract your starting mileage from your current mileage to calculate how many miles you’ve covered since you last filled up

  3. Divide that number by the gallons figure to calculate your total MPG

A grey BMW X7 driving in the desert

What impacts MPG?

There are a few factors that can have an impact on your MPG, and a lot of these come down to your driving style and the model you choose.

  • Larger cars use more fuel as they have more weight to move

  • Cars with an aerodynamic and sleek design use less fuel on average and usually have a better MPG figure

  • Diesel cars are usually more economical as diesel is more combustible than petrol, meaning you need less fuel to generate power

  • Features like mild-hybrid engines, start/stop technology and eco driving modes can also reduce fuel consumption

  • The size of the engine and the power of your car also impacts MPG. Sports cars with plenty of power are more expensive when it comes to fuel costs

  • Driving inefficiently at high speeds and with aggressive braking can also use more fuel

  • Shifting large loads like roof boxes or towing caravans will likely have quite a large impact on your fuel efficiency

Real world car MPG

While you can check the MPG figure of your car before purchasing, bear in mind that these figures are the best possible MPG that you can hit in your vehicle and might not reflect real-world driving.

Always use the WLTP and NEDC as a guideline and expect that you’ll likely get slightly less mileage per gallons of fuel when you actually go about your daily business.

Driving in traffic and having to change gears often can increase how much fuel you use, whereas smooth motorway driving can often be more efficient.

What is the average MPG for a car?

Usually, anything more than 50mpg is an efficient runner when it comes to petrol and diesel cars. This can differ depending on the type of car - a large seven-seater SUV is going to need more fuel to get moving.

Petrol cars usually average around 36mpg, while diesel cars average around 43mpg.

Hybrid cars average 59mpg, while full-electric models average 159mpge.

Your best option for an efficient fuel-powered model is to opt for a diesel, while hybrid and electric models are worth considering if you're ready to make the switch.

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