Most economical UK petrol cars 2021

The most economical petrol cars promise excellent MPG with low running costs. Here are the 10 most frugal cars on sale now.

John Evans
Feb 15, 2021

In the market for a car that's going to save you money on fuel? You may be wondering about the best way to understand which cars have the best fuel economy. Well, it's traditionally diesel cars that have been the undisputed leaders when it comes to saving money on fuel, but with all their issues with emissions recently you'd be forgiven for preferring to opt for something petrol powered instead.

If you’ve been shopping for a new car in recent months, you may have noticed a dramatic change in the fuel economy figures published by manufacturers. Since September 2018, car makers have been testing vehicles under a new, stricter economy test called World Harmonised Light Vehicle Test Procedure (WLTP), which produces results that give the impression that these newer cars are actually delivering worse fuel economy.

The fact is this updated test is much more stringent than anything that came before, so in actual fact what we're seeing is a far more accurate result than we've ever seen before, so while those out-dated fuel economy figures produced by the New European Driving Cycle (NEDC) appear to be better, it's more suitable to say they were simply inaccurate.

Inevitably, with a transition from old to new tests, there’s still lots of conflicting economy information flying around, with old and new figures quoted in different places. Today, all new car economy data must be WLTP-based, but old brochures or specification sheets will be showing the old NEDC figures - and sometimes it’s not always clear which is which.

But you don't need to concern yourself with such things; we're on hand to help you decipher all the facts and figures and bring you this list of ten of the most economical petrol-engined cars.

Most economical petrol cars 2021

WLTP fuel economy test

WLTP stands for World Harmonised Light Vehicle Test Procedure (WLTP). It's a new fuel economy test sanctioned by the EU and intended to produce more representative fuel consumption and CO2 emission figures than its predecessor, the New European Driving Cycle (NEDC). 

Cars are tested in a laboratory for 30 minutes and over 14.4 miles at an average speed of 28.9mph and a maximum of 81mph.

The new test lasts 50% longer than before and the cars are tested over twice the distance. Speeds are higher and gear shifts made to suit the vehicle being tested rather than at set points. Acceleration and deceleration is more aggressive and engines put under a wider range of loads. Finally, to make things tougher still, the ambient temperature at which the car is tested is lower.

1. Peugeot 108

Used deals from £4,699
Monthly finance from £95*
WLTP combined economy

The Peugeot 108 is one of a family of related city cars, the others being the Toyota Aygo and the Citroen C1. However, it is the most economical of the three. Its advantage is so small though that it shouldn't be your only criteria if you're trying to differentiate between them.

Other factors in its favour include its comfortable ride, equipment levels and scope for personalisation. On the downside, the 1.0-litre petrol engine is feeble and the rear seats are more cramped than rivals.


2. Suzuki Celerio

Used deals from £4,995
Monthly finance from £103*
WLTP combined economy

Suzuki’s smallest car is a humble city-dweller designed to do the important things well. Despite being small, it has a roomy and practical interior and in every spec other than the entry-level one there is a competitive level of standard equipment. Its fuel economy figure is almost as good as the Peugeot 108, making it cheap to run, too.

If only the interior looked less low-rent and the steering were a little sharper and less vague it would be a lot more attractive.


3. Toyota Aygo

Used deals from £5,395
Monthly finance from £116*
WLTP combined economy

The Aygo doesn't quite achieve the class-leading economy of the closely related Peugeot 108, but under the new WLTP test, 57.7mpg isn't to be sniffed at. In any case, if you're swayed by its striking looks and that bold, X-shaped nose, the Aygo delivers on the road as well with agile handling.

The 1.0-litre petrol engines are lively too, and although the steering could be sharper and more direct. The back seats are a little cramped but cars like the Aygo are designed primarily for short, urban journeys so that’s unlikely to be an issue for most buyers.


4. Citroen C1

Used deals from £-5,044
Monthly finance from £116*

WLTP combined economy 57.3mpg

The C1 is the least economical in the Toyota Aygo and Peugeot 108 family, but in real-world terms the difference between all three of these cars is likely to be negligable.

Like its cousins, the C1 is nippy and easy to drive but it's cheaper than the other two. This lower price is evident in the car, however, as its interior is the lowest quality too, while it shares the same cramped rear seats as the Aygo and 108. When push comes to shove, issues such as styling and finance offers are likely to favour one over the other.

So, if you like the look of one of the three it's worth considering the other two as well, to see which suits your needs best.


5. Volkswagen Up

Used deals from £4,249
Monthly finance from £120*
WLTP combined economy

The Up has the distinction of being the most economical in another trio of related city cars, sitting alongside the Skoda Citigo and Seat Mii. There’s not much in it but this greater fuel economy is one of several reasons why the VW is regarded as the most rounded of the three.

We also consider the Up to be more grown-up than either the Citigo or Mii, with a better interior and overall build quality, although it's still a trendy little car with an impressive breadth of ability. It has a small boot but so do they all. Prices are also a little higher to suit, so as with the 108-Aygo-C1 trio, it's worth considering which one suits you best.


6. Skoda Citigo

Used deals from £5,000
Monthly finance from £108*
WLTP combined economy
54.3mpg (1.0 MPi 60PS GreenTech)

The Skoda Citigo just trails the VW Up in the economy stakes. Their engines produce the same power but the Citigo is slightly more liberal with its fuel consumption. Nevertheless, it feels just as grown-up and mature as the Up, although its interior feels slightly less sophisticated than the Up, too. It’s an impression most keenly felt in the most basic Citigo, so it's worth opting for a higher specification version if this bothers you.

Otherwise, it’s cheap to run and has a surprisingly roomy interior with a very usefully sized boot for a car that's so small on the outside. The option of a variable boot floor raises the floor closer to the bottom of the boot opening, making it easier to load bulky or heavy items in, while leaving a hidden compartment beneath for additional luggage.


7. Seat Mii

Seat Mii front

Used deals from £5,100
Monthly finance from £120*
WLTP combined economy
53.3mpg (1.0 12v 60PS Design)

The Seat Mii is the least economical of these three, if only by as much as 2mpg. It's a difference that could be easily overcome in the real world and a small enough difference that your driving style is likely to have more of an impact on the fuel economy you get.

In any case, the Mii has a welcome dose of styling flair while being just as comfortable and roomy. Downsides include the fact that the turbocharged petrol motor found in the VW Up isn't an option here and there’s no chance of an automatic either.


8. Seat Ibiza

Used deals from £6,490
Monthly finance from £136*
WLTP combined economy
53.3mpg (1.0 TSI 95PS SE)

The Seat Mii may trail its rivals slightly in terms of fuel economy, but the slightly larger Ibiza is the most economical in its class, with a a fuel economy equal to that of the Mii. That’s some achievement given that you gain a whole load of performance courtesy of the Ibiza's more powerful turbocharged engine (95hp compared with the Mii’s 60hp).

Along with its impressive economy the Ibiza is one of the best small cars available. It's stylish, practical and fun to drive. Unfortunately, poor equipment levels for the most basic models and questionable interior quality let it down. Strong value finance offers mean you could get a higher specification model for less than you think, however.


9. VW Polo

Used deals from £6,799
Monthly finance from £159*
WLTP combined economy
52.3mpg (SE 1.0 TSI 95 5dr)

Even with the same engine, the Volkswagen Polo lags behind the Ibiza in terms of fuel economy. It’s a close thing, though, and for most buyers a small enough difference to go unnoticed. Instead, people looking for a more mature driving experience and a better quality interior will find these elements in the Polo, albeit at a higher price.

The Polo is comfortable, if not entirely thrilling, which may turn off prospective buyers looking for a nippy and fun-to-drive supermini. Instead, it exudes a deep-down quality that no rival can match.


10. Peugeot 208

Used deals from £4,950
Monthly finance from £109*
WLTP combined economy
51.5mpg (1.2 PureTech 82 S&S)

The previous-generation Peugeot 208 is the third most economical supermini in our list. Given it’s about to be replaced by an all-new model, it’s a remarkable achievement and bodes well for its replacement.

Of course, being close to the end of its life cycle, the 208 has started to feel dated inside, lacking some of the tech seen in its newer rivals. However, it still a good-looking car that’s refined and well equipped if not overly exciting. Our advice? Just concentrate on its impressive fuel economy or get a used model for very strong economy at a low price.



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