The price of fuel is a key part of the cost of living for many drivers. This is why miles per gallon (MPG), a measure of a car's fuel efficiency, is one of the key things to consider when looking for a new car.
Vehicles with a high MPG are more energy efficient, so as well as filling up less often, they tend to fall into cheaper road tax brackets too.
If you're considering getting a new car, looking towards the more fuel-efficient end of the market could be a smart move, particularly with the UK government placing high road tax bands on low MPG vehicles. But what are the most fuel-efficient cars on the market?
Take a look through our handy guide to uncover the best MPG cars to suit all budgets.
The 10 most fuel-efficient cars on the market
If you’re looking for a brand-new car, then below you’ll find the most fuel-efficient cars available to purchase in 2020. As you may expect, the Toyota Prius hybrid leads the way, with an official MPG of 90 and a reputation as being the first car to really put the environment at the forefront.
The 10 most fuel-efficient cars on the market include:
1. Toyota Prius 1.8 VVT-i Active Auto
Key facts:
- Price: From £24,885
- MPG: 90
- Cost per mile: 5.3p
- Engine: 1.8-litre
- Road tax: £125 first year, £140 standard rate
The Toyota Prius was the first mass-produced hybrid car on the market and is still a popular choice amongst many drivers, offering a practial and low-emission car. It’s a reliable choice, offers around 63 miles per gallon when road tested and combines a 1.8-litre petrol engine with a hybrid battery to maximise its efficiency.
It’ll set you back around £24,885 for the basic version (‘Active’), with the top of the range model priced at a rather hefty £28,355, but that’s put very few drivers off thanks to its ease of driving and smart and sleek design.
2. Toyota Corolla 1.8 VVT-i Hybrid Icon 5dr CVT
Key facts:
- Price: From £24,195
- MPG: 89
- Cost per mile: 7.7p
- Engine: 1.8-litre
- Road tax: £145 first year, £140 standard rate
The Toyota Corolla petrol hybrid has earned rave reviews since launching and it sits as one of the best performing cars on the market when it comes to MPG. With an official MPG of 89, and road tests placing it around 63, it can definitely compete with the Prius, and will cost you around 7.7p per mile when behind the wheel.
The hatchback has a 1.8-litre engine, with a starting price of £24,195 and is one of the best small cars for MPG on the market right now. It fits into Car Tax Band A, costing £145 in the first year and dropping to £140 thereafter.
3. Citroen C3 1.6 BlueHDi Feel 100hp
Key facts:
- Price: From £15,310
- MPG: 88
- Cost per mile: 8.2p
- Engine: 1.6-litre
- Road tax: £175 first year, £150 standard rate
One of the more comfortable and stylish fuel-efficient cars is the diesel Citroen C3. The Aircross model offers 88 MPG officially, although you can expect to get around 62 MPG while driving, and releases 117g/km of CO2, making it one of the least polluting vehicles around.
It’ll cost you around 8.2p per mile to get around and with five doors, it makes for an ideal family runaround. It’s also one of the cheaper most efficient vehicles with a start price of £15,310.
4. Peugeot 208 1.5L BlueHDi Active 100
Key Facts:
- Price: From £19,160
- MPG: 88
- Cost per mile: 8.2p
- Engine: 1.5-litre
- Road tax: £155 first year, £150 standard rate
The Peugeot 208 first launched back in 2012 but has been given a fuel-efficient makeover that now sees it enjoy 88 MPG in its official spec, with a road testing of around 62 MPG.
The five-door diesel hatchback emits 109g/km of CO2, ahead of the C3, although is more expensive in terms of starting price at £19,160, with road tax around £20 cheaper in the first year.
5. Vauxhall Corsa 1.5 Turbo D SE 102PS
Key facts:
- Price: From £18,405
- MPG: 88
- Cost per mile: 8.2p
- Engine: 1.5-litre
- Road tax: £155 first year, £150 standard rate
The 1.5-litre Turbo Diesel Corsa model is a safe and fuel-efficient car that has been a big hit with young families. With a starting price of just over £18,000 it’s an ideal runaround and has an NCAP four star safety rating.
With an official 88 MPG that drives more like 62 MPG on the road, the Vauxhall Corsa has only enhanced its long and prestigious history. It emits 109 g/km of CO2, and has five doors with a top speed of 117mph.
6. Citroen C4 Cactus BlueHDi Flair
Key facts:
- Price: From £23,315
- MPG: 84
- Cost per mile: 8.2p
- Engine: 1.5-litre
- Road tax: £150 standard rate
The C4 has been given a makeover in a similar vein to the C3 and offers a great MPG as its key selling point.
According to the spec, you’ll get 84 MPG from the five-door diesel vehicle, but it does perform at around 59 MPG following test drives.
It’ll do 0-60mph in 10 seconds and emits 122g/km of CO2. For a small family car, you won’t find many better than this one in terms of efficiency, although there is a cost that comes with that, starting at £23,315.
7. Vauxhall Astra Sports Tourer 1.5 Turbo D
Key facts:
- Price: From £20,310
- MPG: 83
- Cost per mile: 8.7p
- Engine: 1.5-litre
- Road tax: £150 standard rate
The Astra Sports Tourer from Vauxhall is the highest ranked estate car on this list and offers 83 MPG officially (you’ll get closer to 58 MPG), with a cost of around 8.7p per mile.
This five-door car has a 1.5-litre turbo diesel engine and a top speed of 124mph. It emits 114g/km of CO2 and is priced at around £20,000 for the most basic model.
8. Honda Civic 1.6 i-DTEC Turbo S
Key facts:
- Price: From £20,850
- MPG: 83
- Cost per mile: 8.7p
- Engine: 1.6-litre
- Road tax: £150 standard rate
The Honda Civic is one of the most recognisable models from the brand since launching way back in 1972 . Back then you wouldn’t have got 83 miles per gallon (official figure, it performs closer to 58 MPG), and it’s certainly Honda’s best performing diesel car on the market.
The 1.6 i-DTEC Turbo S model starts from £20,850 and has a top speed of 125mph and an NCAP safety rating of 4/5, making it a high quality, fuel-efficient small family offering from the brand.
9. Peugeot 308 SW 1.5L Blue HDi Active 100
Key facts:
- Price: From £21,755
- MPG: 82
- Cost per mile: 8.8p
- Engine: 1.5-litre
- Road tax: £150 standard rate
The Peugeot 308 1.5-litre Active model is the second estate car to make the list and offers 58 MPG according to road tests, with the official spec being 82 MPG. With a similar starting price to much of the top 10, this diesel estate could be a family car worth exploring.
It’s a five-door vehicle with a 5-star NCAP safety rating and is in Car Tax Band A with emissions hitting 120g/km in CO2.
10. Hyundai IONIQ Hybrid 1.6 GDi SE Connect
Key facts:
- Price: From £23,850
- MPG: 81
- Cost per mile: 8.5p
- Engine: 1.6-litre
- Road tax: £140 standard rate
This hybrid from Hyundai officially gives you 81 MPG with a real performance of around 57 MPG and is a petrol hybrid that competes nicely with the Prius.
It’s slightly cheaper than its Toyota rival at £23,850 and emits just 102g/km in CO2. It has a 1.6-litre engine, with five doors and a 5-star NCAP safety rating, making it a popular offering with young families.
Fuel-efficient cars on a budget
For most drivers, one of the biggest factors when buying any car is the cost of the vehicle itself. The good news is, no matter what your budget, there are fuel-efficient cars on the market.
Below you’ll find the top five brand-new cars that offer fuel efficiency for under £15,000 and the top five fuel-efficient cars for those with a high-end budget.
Best fuel-efficient cars for under £15,000
| Position | Car | Starting price |
Official MPG | Likely MPG | Fuel cost per mile | CO2 emissions (g/km) |
| 1 | Peugeot 108 | £12,785 | 79 | 56 | 6.2p | 110 |
| 2 | Citroen C1 | £11,015 | 79 | 56 | 6.2p | 108 |
| 3 | Dacia Logan | £7,670 | 79 | 55 | 6.5p | 115 |
| 4 | Fiat 500 | £12,064 | 77 | 54 | 6.4p | 119 |
| 5 | Ford KA+ | £11,050 | 75 | 53 | 6.8p | 123 |
MPG source: Next Green Car
Start price source:
Peugeot 108 - What Car?
Citroen C1 - What Car?
Dacia Logan - Auto Express
Fiat 500 - Auto Express
Ford KA+ - Auto Car
Best fuel-efficient luxury cars
| Position | Car | Starting price |
Official MPG | Likely MPG | Fuel cost per mile | CO2 emissions (g/km) |
| 1 | Audi A8 | £75,760 | 49 | 35 | 10.3p | 180 |
| 2 | Mercedes S-Class Saloon | £76,640 | 47 | 33 | 11p | 180 |
| 3 | Lexus LS | £76,900 | 46 | 32 | 10.5p | 209-175 |
| 4 | Mercedes S-Class Coupe | £113,215 | 29 | 21 | 16.5p | 237 |
| 5 | Rolls Royce Phantom | £363,600 | 21 | 15 | 22.8p | 341 |
MPG source: Next Green Car
Start price source:
Audi A8 - What Car?
Mercedes S-Class - Mercedes online
Lexus LS - Lexus online
Mercedes S-Class Couple - Mercedes online
Rolls Royce Phantom - Auto Express
Fuel-efficient cars by size
There are fuel-efficient cars to suit all needs. Whether you’re a family of four looking for a new family car or an adventurer looking for the most economical off-road vehicle, we’ve broken down the best fuel-efficient cars in all sizes.
The best fuel-efficient family cars
| Position | Car | Starting price |
Official MPG | Likely MPG | Fuel cost per mile | CO2 emissions (g/km) |
| 1 | Toyota Prius | £24,885 | 90 | 63 | 5.3p | 94 |
| 2 | Hyundai IONIQ | £23,850 | 81 | 57 | 8.5p | 102 |
| 3 | Peugeot 508 | £27,355 | 81 | 57 | 6.3p | 124 |
| 4 | Skoda Superb | £24,855 | 76 | 54 | 6.7p | 127 |
| 5 | Mercedes B-Class | £29,005 | 74 | 52 | 6.8p | 122 |
MPG source: Next Green Car
Start price source:
Toyota Prius - What Car?
Hyundai IONIQ - What Car?
Peugeot 508 - Peugeot online
Skoda Superb - Skoda online
Mercedes B Class - Next Green Car
The best fuel-efficient coupe/sports cars
| Position | Car | Starting price |
Official MPG | Likely MPG | Fuel cost per mile | CO2 emissions (g/km) |
| 1 | Mercedes C-Class Coupe | £39,705 | 64 | 45 | 7.9p | 133 |
| 2 | BMW 2 Series Coupe | £27,105 | 61 | 47 | 8.3p | 149 |
| 3 | BMW 4 Series Convertible | £45,785 | 60 | 42 | 8.5p | 184-129 |
| 4 | Lexus RC | £40,905 | 59 | 42 | 8.2p | 141 |
| 5 | Mini Cooper Convertible | £20,630 | 57 | 40 | 8.4p | 142 |
MPG source: Next Green Car
Start price source:
Mercedes C-Class Coupe - Mercedes online
BMW 2 Series Coupe - BMW online
BMW 4 Series Convertible - BMW online
Lexus RC - Lexus online
Mini Cooper Convertible - Mini online
The best fuel-efficient SUVs
| Position | Car | Starting price |
Official MPG | Likely MPG | Fuel cost per mile | CO2 emissions (g/km) |
| 1 | Vauxhall Grandland X | £24,600 | 75 | 53 | 6.8p | 137 |
| 2 | Citroen C5 | £23,225 | 75 | 53 | 6.8p | 137 |
| 3 | Nissan Qashqai | £20,565 | 75 | 53 | 6.8p | 139 |
| 4 | Peugeot 5008 | £28,980 | 74 | 52 | 6.8p | 139 |
| 5 | Lexus UX | £29,950 | 72 | 51 | 6.7p | 120 |
MPG source: Next Green Car
Start price source:
Vauxhall Grandland X - Vauxhall online
Citroen C5 - Car Buyer
Nissan Qashqai - Nissan online
Peugeot 5008 – Peugeot online
Lexus UX - Lexus UX
Most fuel-efficient used cars
If you’re looking to find a used car on the market, there are several fuel-efficient options for around the £5,000 mark. Of course, this can vary from each car dealer and the overall condition and year of the car, but below are some of the top fuel-efficient used cars currently available on the market.
The best fuel-efficient used cars
| Position | Car | Starting price |
Official MPG | Likely MPG | Fuel cost per mile | CO2 emissions (g/km) |
| 1 | Fiat 500 | £5,500 | 69 | 54 | 9p | 95 |
| 2 | Ford Fiesta 1.6 TDCi | £5,137 | 71 | 51 | 10p | 104 |
| 3 | Toyota Aygo | £4,950 | 73 | 51 | 9.5p | 113 |
| 4 | Citroen C1 | £4,999 | 66 | 49 | 10p | 99 |
| 5 | Volkswagon Up! | £4,499 | 61 | 43 | 11.2p | 120 |
MPG source: Next Green Car
Used price source: All prices taken from Auto Trader and based upon an average as of 28 September 2020.
Fiat 500 - Auto Trader
Ford Fiesta - Auto Trader
Toyota Aygo - Auto Trader
Citroen C1 - Auto Trader
Volkswagon Up! - Auto Trader
How is fuel efficiency calculated & what is miles per gallon?
Fuel efficiency is one of the key factors considered when it comes to car manufacturing these days, and is something buyers should also consider, as it will have a big impact on how much you spend on fuel.
To discover how efficient a car is, the MPG, or miles per gallon, data is the most important aspect to explore.
Car manufacturers are required to release their MPG figures by law, although they can often be skewed compared to real-life. On the road, you must consider conditions, traffic, speed limits and climate. Therefore, you’ll often find an official MPG figure and a real-life MPG that has come from extensive testing on roads or in more accurate testing environments.
What is ‘miles per gallon’?
Miles per gallon is a figure which represents the number of miles you’re able to drive per gallon of fuel in your car. Therefore, the higher the figure, the more fuel-efficient a car is.
It is also worth noting the CO2 emissions of the vehicle, as lower emissions are not only better for the environment, but will also lower the amount of tax you pay on your vehicle.
First tax payment upon registration of the vehicle:
| CO2 emissions (g/km) | Petrol cars and diesel cars that meet RDE2 standard | Other diesel cars |
Alternative fuel cars |
| 0 | £0 | £0 | £0 |
| 1-50 | £10 | £25 | £0 |
| 51-75 | £25 | £110 | £15 |
| 76-90 | £110 | £135 | £100 |
| 91-100 | £135 | £155 | £125 |
| 101-110 | £155 | £175 | £145 |
| 111-130 | £175 | £215 | £165 |
| 131-150 | £215 | £540 | £205 |
| 151-170 | £540 | £870 | £530 |
| 171-190 | £870 | £1,305 | £860 |
| 191-225 | £1,305 | £1,850 | £1,295 |
| 226-255 | £1,850 | £2,175 | £1,840 |
| 255+ | £2,175 | £2,175 | £2,165 |
Tax source: Gov.uk
Second tax payment and further tax payments on vehicle:
| Fuel type | Single 12 month payment | 12 monthly payments by Direct Debits |
Single 6 month payment | Single 6 month payment by Direct Debit |
| Petrol or Diesel | £150 | £157.50 | £82.50 | £78.75 |
| Electric | £0 | N/A | £0 | N/A |
| Alternative | £140 | £147 | £77 | £73.50 |
Tax source: Gov.uk
Simple steps to driving more economically
Alongside purchasing a fuel-efficient car, if you are keen to maximise efficiency, then you need to drive more economically, too.
This involves a shift in mindset and taking practical steps, such as lightning the load in your car. You can start by unloading any heavy objects being stored in the boot of your car, or items such as bicycle racks and roof racks if they aren’t needed.
In the case of racks, these will also cause unnecessary drag when they aren’t being used and ultimately lead to a less fuel-efficient performance of your car.
Other steps to consider include switching off the air conditioning or heating when it isn’t needed, as it can put strain on the engine. Planning your journeys in advance can also have a positive effect on efficiency.
You can find out many more tips and tricks to increase your fuel-efficiency by reading our dedicated Solved article.
Calculate the cost of your trip
Are you looking to explore how fuel-efficient your car is? Perhaps you have a journey planned or would like to see how much you can save on your daily commute.
Our fuel tracker can help you calculate the cost of your journeys. Click here to see the price of fuel with the Ageas Fuel Tracker tool.
At Ageas, we try to provide car insurance policies to as many drivers as we can. But we can’t promise cover for every single customer and car, and this may include some versions of the fuel-efficient cars mentioned above.