What does MPG stand for?

MPG stands for 'miles per gallon'. It measures how many miles a car can travel using one gallon of fuel and is the standard UK fuel efficiency measure.

What is MPG in litres?

Fuel in the UK is sold in litres, while MPG is miles per gallon. One UK gallon is 4.546 litres. So to get your MPL, simply divide your MPG by 4.546.

Yes, 40mpg sits at the efficient end for most everyday petrol and diesel cars.

What is considered a bad MPG?

Under 30mpg is generally poor for a standard passenger car, but context matters. For example, a performance car at 25mpg may be normal for its class.

Can I drive 2 miles on empty?

Most cars have 40-45 miles of range once the warning light activates. All cars are different though, so it's best not to risk being in this situation. Plus, regularly running low can damage the fuel pump, so it's best avoided.

What is a very good MPG for a car?

60mpg+ is deemed very good MPG for a car. This is typically hybrids and PHEVs because they're generally more efficient. For standard petrol and diesel cars, 50mpg+ is seen as excellent.

How do I work out my car’s MPG?

To calculate MPG, fill your tank and note your mileage. Next time you refuel, record the litres used and miles driven. Use the formula: MPG = (miles driven ÷ litres used) × 4.546. This gives your car’s MPG based on real-world driving.

What is MPG? Car fuel efficiency explained

Written by Joe Achilles Updated 03 Jun 2026

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Whether you’re looking for a new car or just trying to save money on petrol, it’s important to understand fuel efficiency. And when it comes to fuel efficiency, you’ll often hear the term miles per gallon or “MPG”. But what does MPG actually mean, what is a good MPG for a car, and how do you work it out yourself?

We’ve explained all, including what impacts MPG, how official figures are tested, and what driving habits you can adopt to try and save on fuel.

What is MPG?

First, let’s start with what MPG stands for and what it actually means.

What does MPG mean?

MPG stands for ‘miles per gallon’. It tells you how many miles a car can travel on one gallon of fuel. In short, it’s a way of measuring car fuel efficiency.

For example, if a car has an MPG of 50, that means it can go 50 miles using just one gallon of petrol or diesel. The higher the MPG, the further you can drive without needing to fill up, which usually means spending less on fuel. ou may also see MPG referred to as fuel consumption or fuel economy - these all mean the same thing.

What impacts MPG?

Lots of things can affect your car’s MPG:

Driving style: If you brake a lot or accelerate hard it uses more fuel. Smooth, steady driving can be more efficient.
Speed: Driving faster than 60mph can reduce fuel efficiency. Motorway driving at high speed is often less efficient than a steady A-road cruise.
Tyre pressure: Under-inflated tyres create more resistance and therefore use more fuel. Keeping tyres at the manufacturer's recommended pressure can be a simple way to protect your MPG.
Car weight: The more weight your car carries, the harder it works! More weight can mean more fuel use.
Engine size and type: Larger or more powerful engines often use more fuel, while hybrids or smaller petrol engines tend to be more efficient.
Car make and model: Shape and aerodynamics can all affect MPG. Smaller, lighter cars usually use less fuel than big, heavy ones.

How car type affects fuel efficiency

If you’re trying to reduce your fuel spend, choosing the right type of car can make a big difference.

Smaller cars tend to be more fuel-efficient, simply because they’re lighter. They usually offer better miles per gallon, making them a great option for city driving or regular commutes. In contrast, larger vehicles like SUVs, vans, and performance models often have lower MPG figures due to their size, power, and weight.

Hybrid and electric vehicles are typically the most efficient overall, and many hybrids can achieve 60mpg or more! This is especially true in stop-start traffic where regenerative braking helps recharge the battery.

It’s also worth keeping in mind that even car body style can play a role. For example, saloons and hatchbacks are often more efficient than boxier shapes like 4x4s because they’re more aerodynamic.

Thinking about making the switch? Take a look at our guide to the pros and cons of electric cars to see if an EV is right for you.

Why does every car have multiple MPG figures?

Cars have multiple MPG figures because fuel efficiency can change depending on driving conditions, road type, and speed.

In the UK, official fuel economy figures are now measured using the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). WLTP replaced the older New European Driving Cycle (NEDC) test for all new cars from 2017.

The older NEDC figures were considered unrealistically high, because they were based on outdated laboratory testing with low speeds and conditions that don’t reflect everyday driving. WLTP is seen as more reliable because it uses a more modern and demanding test cycle based on real driving data.

The older NEDC terms you might come across are “city/urban”, “highway/extra-urban” and “combined”, but these are no longer officially used. WLTP replaced these with a more detailed breakdown:

Low (similar to city/urban driving)
Medium (similar to slower suburban or mixed driving)
High (similar to faster rural roads)
Extra-high (similar to motorway driving)
Combined (an average of all test phases)

For most drivers, the Combined WLTP figure is the most useful figure. It brings together city, suburban, and motorway driving into one average, giving a balanced view of how a car is likely to perform in everyday use. That’s why it’s advisable to use this one when comparing cars.

What is a good fuel efficiency?

So, what counts as good MPG exactly? Let’s look at it in more detail.

Is higher MPG better?

Yes, higher MPG means better fuel efficiency. A higher number means you’ll go further on each gallon of fuel, which is better for your wallet and the environment.

If you do lots of long journeys, a car with good miles per gallon can help you spend less on fuel and reduce your carbon footprint.

How many MPG is good?

A good MPG for a car depends on the type of vehicle, fuel type, and how you use it. But generally, anything above 40mpg is considered good. For most modern petrol or diesel cars, an MPG in the 40–50 range is typical. Hybrids and plug-in hybrids can sometimes go over 60 or even 70mpg in ideal conditions.

There’s no golden number when calculating fuel efficiency, but generally speaking:

Over 60mpg is considered very good
40–60mpg is good for modern cars
30–39mpg is average
Under 30mpg is usually seen as poor for everyday use

What is the average MPG for a car in the UK?

In the UK, the average MPG for cars is 38mpg with petrol cars slightly less efficient than diesel.

Average MPG on newer cars is often higher, thanks to better technology and stricter emissions standards. If you really want to save, considering a hybrid might be a good idea, as even 60mpg is much higher than average.

Which cars have the best MPG in the UK?

The best MPG cars tend to be hybrids, plug-in hybrids (PHEVs), and small petrol superminis. This is because hybrids save energy when you brake and reuse it to help the engine in stop-start traffic. Plug-in hybrids have bigger batteries that charge, so they can run on electric power for short trips. Small petrol superminis are light and have small engines, so they need less fuel to move and are more efficient overall.

It’s worth bearing in mind though that some PHEVs are recorded as 70mpg but these are calculated under test conditions assuming a fully charged battery, so real-world figures vary significantly.

Here’s a list of some of the most efficient cars according to What Car:

Car model	Fuel Type	Official WLTP MPG
Toyota Yaris Cross 1.5 Hybrid	Hybrid petrol	62.7mpg
Toyota Yaris 1.5 Hybrid	Hybrid petrol	68.8mpg
Suzuki Ignis K12D 1.2 Dualjet Hybrid	Mild hybrid petrol	55.7mpg
Skoda Octavia 2.0 TDI 115	Diesel	64.8mpg
Honda Jazz 1.5 i-MMD Hybrid	Hybrid petrol	61.4mpg
Volkswagen Up 1.0 S/S 60	Petrol	50.7mpg

How to work out your MPG

Wondering how to work out MPG yourself? It’s easier than you think.

Here’s a simple way to calculate MPG:

Fill your fuel tank to full and take a note of your current mileage.
Drive as normal until you next fill up.
Fill the tank to full again, noting how many litres you’ve added.
Record how many miles you’ve driven since the last fill-up.

Now use this formula:

MPG = (miles driven ÷ litres used) × 4.546 (There are 4.546 litres in a UK gallon).

The number you're left with is your MPG.

How can I improve my car's MPG?

There are some things you could do to try and improve your car’s MPG, mostly by how you drive and how well you look after your car. Small changes to your habits and maintenance could make a noticeable difference over time. Here are a few ways you can improve it:

Smooth driving style – Drive gently with steady speeds, avoiding harsh acceleration and braking.
Speed – Driving at lower, consistent speeds is usually more fuel efficient than fast motorway driving.
Tyre pressure – Keep tyres properly inflated to reduce resistance and improve efficiency.
Remove unnecessary weight – Take out heavy items and remove roof boxes or roof racks when not needed.
Avoid short cold starts – Short trips use more fuel, so combining journeys can help improve MPG.
Turn off ancillaries when not needed – Air con, heated seats, and demisters can increase fuel use.
Regular servicing – Keeping your car well maintained helps it run more efficiently.

The takeaway

Whether you’re comparing cars, trying to reduce your fuel costs, or just want to understand MPG means, understanding average fuel consumption is important. It could help you save your hard earned money and make a big difference over time.

As well as choosing your car carefully, you can get the most out of your fuel tank by adjusting your speed and driving habits where possible.

Want to understand the full cost of running a car beyond fuel? Read our complete guide to how much cars cost to run.

Ready to start looking for your new car? Get a free quote today to see if you’re eligible for car finance.

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