The eight most economical cars

Last updated by mustard.co.uk on May 7th, 2021

Almost everybody wants an economical car, don’t they? Cars that use less fuel give you – quite literally – more bang for your buck. Whether you’re doing mega miles or just pootling around town, picking an efficient car that’s right for your needs will be of the most benefit to your pocket.

We’ve rounded up eight of the most efficient cars on sale today, according to their official figures. Since 2018, this has been based on what’s known as WLTP, or the Worldwide Light Vehicle Test Protocol. This is a series of tests which aim to more closely replicate the fuel economy you’ll find in real-world driving, unlike the former NEDC (New European Driving Cycle) tests, which gave very unrealistic numbers indeed. Fuel economy in the UK is rated in mpg, or miles per gallon.

We’ve concentrated this list on petrol and diesel cars. You’ll notice the omission of plug-in hybrid and fully electric models. The latter is for obvious reasons – one can’t judge fuel economy if one’s driving a car that doesn’t use conventional fuel. Plug-in hybrids are different, and under WLTP tests tend to return mpg figures in the hundreds. This is very dependent on your behaviour with regards to charging, and so can’t be directly compared to pure combustion-engined cars.

Is petrol or diesel more efficient?

Diesels, for long journeys, generate the best economy figures. For regular, very short trips, a petrol engine is more suited as it can reach the optimal temperature and give better milege.

A cold diesel engine is not as economical as one that is up to operational temperature, and regular short running can create running issues as it is outside design expectation. Issues with modern diesel, such as the microbial formation of fungus and bacteria can also present issue if fuel is stood for periods of time, fuelled by the water absorbing qualities of biodiesel.

Once you have decided which fuel type suits your needs, here is the guide for you – a rundown of some of the most fuel-efficient cars on the market.

The most economical petrol cars

If short journeys are your most regular trip, a petrol car is the best tool for the job. They are often cheaper to repair and maintain and generally less expensive to buy. For a cheap but cheerful option, small and lightweight cars can pull impressive fuel economy.

 

Toyota Aygo 1.0 VVT-i 

The Toyota Aygo (and its two mechanically identical siblings, the Citroen C1 and the Peugeot 108) are currently the most efficient pure petrol cars you can buy today. They return an impressive 58.9mpg.

Though small and rather cramped, they’re good fun to drive around the city, and most models have a useful touchscreen infotainment system.

Suzuki Ignis 1.2 

As one of the lightest cars on sale today, you might well expect the Suzuki Ignis to return impressive fuel economy – and it does. Thanks to its featherweight construction and mild-hybrid boosted engine, Suzuki claims an excellent 55.7mpg.

Plenty of equipment as well as a really adorable design make the Ignis surprisingly desirable for such a small, cheap car, and it’s even available with four-wheel drive – unique in this area of the market. Your fuel economy will suffer if you tick that option box, though.

Vauxhall Corsa 1.2 75PS 

The re-vamped Vauxhall Corsa has sleeker looks which appears to translate into fuel efficiency. The 1.2-litre petrol model in its base form achieves 53.3mpg, with the slightly meatier, turbo-equipped 1.2 pulling a still respectable 52.3 MPG.

Now based on the same underpinnings as the excellent Peugeot 208, this Corsa’s far better to drive than its predecessor was, and prices remain low so it’s still an excellent first car.

Fiat 500 1.0 Hybrid 

There’s a new, shiny, all-electric Fiat 500 on sale now, but don’t be fooled – the old model’s still being built and it’s still selling like hotcakes. And thanks to a recent engine update that replaced its old 1.2-litre unit with a 1.0-litre mild-hybrid affair, it’s more efficient than ever.

Fiat claims 53.3mpg from the 500 thus equipped, which is good news for its legions of fans – who love its cheeky styling, fun handling and endless customisation.

 

The most economical diesel cars

There is no doubt about it, a diesel will squeeze more miles out of the supplied fuel than any petrol. For those who want to economically run regular motorway routes, it is still the best option. Once painted as smelly and noisy, the modern diesel does not deserve such a reputation. And despite horror stories to the contrary, new diesel cars are as clean as any other when it comes to harmful exhaust emissions.

Peugeot 208 1.5 BlueHDi 

The Peugeot 208’s 1.5-litre diesel engine is likely to be something of a niche choice, but for drivers who cover long distances there’s nothing more efficient. Peugeot claims a remarkable 71.4mpg, even under the strict WLTP testing protocols.

You don’t have to put up with a rubbish car for that, either. The 208 offer striking styling, a gorgeous (if quirky) interior and a pleasant driving experience.

Vauxhall Corsa 1.5 Turbo D 

The Vauxhall Corsa makes this list once more and unsurprisingly, as it’s very closely related to the Peugeot 208 (above) it returns similarly excellent fuel economy.

Volkswagen Golf 2.0 TDI 

Volkswagen may be counting on its new range of electric cars to propel it into the future – but it’s not done with diesel yet. That’s proven by the 2.0-litre diesel unit in its latest Volkswagen Golf, which is smooth, quiet, clean, and returns 68.9mpg.

For our money we’d step up to a slightly more powerful unit in return for a marginal decrease in fuel economy, but if you want the very highest numbers even this entry-level model will cruise effortlessly. And you’ll also end up with a high-tech and classy family hatchback into the bargain.

SEAT Leon 2.0 TDI

As you might know, the SEAT Leon’s very closely related to the Volkswagen Golf, and uses many of the same engines. Slightly cheaper, perhaps a bit more stylish and with a hint of Spanish flair, the Leon trails the Golf slightly for efficiency, returning 67.3mpg. Which is still remarkable.

Is your insurance as economical as your car?

While smaller and cheaper petrol cars can be far more economical to insure, diesel engined-cars are typically far pricier to buy and more complex to run – driving up their insurance prices. However, if you are not yet ready to give up on diesel, there are still options, mustard.co.uk may be able to help you find the right deal for you. Our Cheapest Price Guarantee* means that you shouldn’t have to choose between the confidence of protection or getting a good deal. So, if you find a like for like quote anywhere else online for your car insurance, we’ll beat it* – simple as that.

Related articles that you may find of interest

The eight cheapest new cars to insure
The five most reliable cars

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