Cars with the best fuel efficiency

Keep costs down with an affordable car that’s cheap to fuel. We pick eight top choices available for less than £15,000

Graham Hope
Oct 25, 2021

Everyone has different priorities when it comes to what they want from their car, and for many, affordability is key. That generally means keeping the purchase price - or PCP finance monthly payments in most cases - and running costs down, with fuel economy particularly important in the long term. Nobody wants to be constantly emptying their bank account filling up at the pumps.

It’s one of the reasons that fuel economy figures feature so prominently in the marketing of cars, and the guidelines have been tightened in recent years in an attempt to ensure that cars are able to get closer to the figures that manufacturers claim are possible - something that wasn't always the case with older models.

Here we’ve picked eight such cars that will keep your fuel costs down and will be affordable to purchase. All are available for under £15,000 on BuyaCar with similarly affordable monthly payments available.

We’ve gone for a variety of car types to provide a choice of small city cars and bulky SUVs, and there’s even the option of an electric model, which will make filling up with fuel a thing of the past.

Cars with the best fuel efficiency

1. Mitsubishi Outlander PHEV

Used deals from £14,790
Monthly finance from £0*

One of the big success stories of recent years has been the petrol-electric Mitsubishi Outlander plug-in hybrid SUV, or the PHEV as it is known. Strong sales have ensured there are loads on the road, meaning there are plenty of used models available, even under £15,000 - that's a lot of car for your money.

Keep the batteries charged up and you should be able to do up to around 28 miles on electricity alone, while it is able to theoretically return 139mpg under the latest fuel economy testing guidelines if you make full use of all that electric power. And if you've heard that Mitsubishi is no longer developing cars for Europe, fear not, as dealers are expected to remain open for a while to cater for servicing and spares for existing cars.


2. Peugeot 108

Used deals from £5,988
Monthly finance from £224*

City cars are the most cost-effective entry point into motoring for many and the 108 is one of the best value options on the table. It was developed alongside the Citroen C1 and Toyota Aygo, and is mechanically very similar to both.

However, the 108 is arguably the best looking of the trio, in either three- or five-door guise, and although performance from the 72hp 1.0-litre petrol engine is nothing to write home about, when fitted with the automated manual transmission, which makes it easier to drive, it promises an extremely respectable 55mpg.

Price is what makes this urban runaround so appealing, though. With used models on starting from around the £5,000 mark, car ownership is unlikely to get much cheaper.


3. Skoda Citigo

Used deals from £6,000
Monthly finance from £0*

If the city car route is of interest to you, but you don’t want to go for one of the Peugeot/Citroen/Toyota trio, then the Skoda Citigo may be for you. As with the 108, C1 and Aygo, it has very closely related siblings in the shape of the Volkswagen Up and the Seat Mii.

Where the Citigo appeals is with its sheer all-round competence. It’s more spacious than the 108, C1 and Aygo, and generally more attractively priced than the Up and Mii, although perhaps not as cheap as you might expect a small Skoda to be. Four-year-old examples can go for around £7,000 - though you'll want to go for finance to get more affordable monthly payments - and you’ll get up to 55.4mpg from the entry-level 60hp engine.

The Citigo, Mii and Up are all now available as electric versions, and while they currently cost a whole lot more than these petrol models, it's worth keeping an eye on just how affordable the future of cheap driving is going to become. Don't expect show-stopping electric ranges from these, though.


4. Volkswagen Polo

Used deals from £5,800
Monthly finance from £237*

The Polo is VW’s Ford Fiesta-sized supermini, and it delivers a big car driving experience, great build quality and an attractive blend of decent performance and fuel economy. In many ways, it is now a viable alternative to the larger, more expensive Golf.

If fuel economy is a concern, it is particularly attractive with the turbocharged 95hp 1.0-litre petrol 'TSI' engine, which delivers a claimed 51.4mpg. And although the Polo is pricier than many rivals, it still makes for an affordable used car.


5. Lexus CT

Used deals from £15,202
Monthly finance from £0*

The CT is another hybrid on our list, but a different kind to the Mitsubishi Outlander PHEV. It’s marketed as a ‘self-charging hybrid’, which from an owner’s point of view essentially means you don’t have to plug it in, though the CT does have a smaller battery pack than the Outlander, meaning less electric range. But the mix of electric and 1.8-litre petrol power does still have benefits at the pumps, with the CT 200h delivering up to a promised 55mpg.

The upmarket hatchback also comes with the other benefits of Lexus ownership such as excellent build quality and the best dealer service in the industry.


6. Kia Niro Hybrid

Used deals from £13,800
Monthly finance from £0*

The Niro is an interesting car, having been developed as a self-charging hybrid, plug-in hybrid and pure electric model, just like its sister car, the Hyundai Ioniq. But it’s the Niro Hybrid we’re looking at here, with a clutch of models now available for less than our benchmark £15,000 figure on BuyaCar.

The high-riding crossover is pleasant enough to drive and will come with the remainder of the Korean company’s industry-leading seven-year warranty, which gives great peace of mind. The hybrid version pairs a 1.6-litre petrol engine with an electric motor to give an attractive claimed 59mpg, and conventional styling will appeal to those put off by the more radical looks of other hybrids.


7. Nissan Leaf

Used deals from £9,995
Monthly finance from £0*

One way of reducing your fuel bills is by opting for a fully electric car, which, of course, doesn’t require conventional fuel at all - just electricity. And although prices for new electric cars remain on the high side, you may be surprised to learn that used models are increasingly affordable.

The previous-generation Nissan Leaf is a case in point - a quick search on BuyaCar reveals an array of 24kWh models available from just over £8,000. You’ll be getting a car that has fared well in owner satisfaction surveys, with a real-world range of around 80-90 miles, which should be more than enough for most town or city dwellers. While you won’t have to fill up, bear in mind the car will need regular charging, so you’ll need access to a charger at home or be willing to track down public chargers. You can also get a 30kWh battery, while the newer version comes with a 40kWh or 62kWh battery if you're concerned about range. 


8. BMW 4 Series

Used deals from £14,000
Monthly finance from £300*

Affordable sporty cars with reasonable fuel economy are a rare beast. But one that may be worth considering is the BMW 4 Series. This two-door coupe version of the 3 Series is undeniably pleasing to drive, looks good in an understated way and in 2.0-litre 420d diesel form, is acceptable in terms of its fuel consumption, with 50mpg claimed to be achievable.

Running costs won’t be super cheap, but buy the right model and the purchase price needn’t be too daunting - or you can go for PCP finance for low monthly payments. BuyaCar has a handful of five-year-old 420ds that fall under our £15,000 threshold.


*Representative PCP finance - Ford Fiesta:

48 monthly payments of £192
Deposit: £0
Mileage limit: 8,000 per year
Optional final payment to buy car: £2,923
Total amount payable to buy car: £11,926
Total cost of credit: £2,426
Amount borrowed: £9,500
APR: 9.9%

Buyacar is a credit broker, not a lender. Our rates start from 6.9% APR. The rate you are offered will depend on your individual circumstances.


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