True MPG: most and least efficient cars revealed

What Car?'s laboratory tests use a real-world driving route to show what fuel economy you can really expect. So, what are the best and worst performing cars?...

Suzuki Ignis - True MPG logo
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What Car? team
24 Jan 2020 12:40

What Car?’s True MPG real-world fuel economy figures show what sort of efficiency you can really expect from your car.

Tests are conducted in a laboratory to ensure repeatability within 1%, but they are based on a real-world route that takes in town, rural and motorway driving.

The results reflect what's achievable if you’re driving gently and sticking to speed limits, but aren’t resorting to any unrealistically slow acceleration or special 'hypermiling' techniques.

True MPG is not only fully reflective of real-world performance, but much more realistic than the official government fuel economy figures that car manufacturers have to quote.

The True MPG tests are carried out under tightly controlled conditions: climate control is always set to 21deg and cars due to be tested are stored overnight at a set 23deg so they all start with exactly the same engine temperature and in the same ambient air temperature.

In this article we reveal the 10 most efficient cars we've tested so far – and the 10 that used the most fuel.


The 10 most fuel-efficient cars tested:

10. Volkswagen Up 1.0 TSI 90

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Volkswagen Up

True MPG 53.7mpg

It's been around a while, but the Up remains one of the best city cars on sale, thanks to its smart interior and fun handling. This turbocharged version offers much punchier acceleration than the cheaper, non-turbo models, in addition to returning almost 54mpg in our True MPG test.

Read our full Volkswagen Up review >>


9. Seat Ibiza 1.0 TSI 95

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New Ford Fiesta & Seat Ibiza vs Skoda Fabia

True MPG 54.0mpg

The 1.0 TSI 95 Ibiza is a former What Car? Small Car of the Year, thanks to its sharp handling, remarkably spacious interior and strong yet efficient petrol engine. And while it's since been surpassed by the Volkswagen Polo, it remains a fine choice.

Read our full Seat Ibiza review >>


=6. Renault Kadjar 1.5 dCi 110

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New Vauxhall Grandland X vs Renault Kadjar vs Skoda Karoq

True MPG 55.2mpg

Renault's Kadjar SUV is closely related to the hugely popular Nissan Qashqai, but it’s a slightly more fuel efficient choice, being capable of more than 55mpg in real-world driving if you go for the 1.5-litre diesel engine.

Read our full Renault Kadjar review >>


=6. Skoda Citigo 1.0 60

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Used test: Fiat 500 vs Skoda Citigo

True MPG 55.2mpg

These days the Citigo is offered only as a fully electric car, but if you're buying used it's often cheaper than its petrol sister cars – the Up and the Seat Mii – despite being just as good to drive. Just bear in mind that this engine feels rather underpowered once you're outside the city limits.

2016 Suzuki Baleno 1.0 Boosterjet review

True MPG 55.2mpg

Level with the Kadjar and Citigo in terms of its True MPG result is the Suzuki Baleno. A small yet practical hatchback, it was discontinued in 2019.

Read our full Suzuki Baleno review >>


5. Volkswagen Up 1.0 75

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New Volkswagen Up vs Hyundai i10 vs Renault Twingo

True MPG 55.9mpg

Volkswagen's city car make a second appearance in the top 10, this time with the less powerful 74bhp 1.0-litre petrol engine. The Up has plenty of virtues, but if your top priority is saving money at the pumps, this is the version to go for.

Read our full Volkswagen Up review >>


4. Seat Leon 1.6 TDI 110 Ecomotive

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2019 Seat Leon front

True MPG 56.0mpg

The Leon is Seat's answer to the Ford Focus and Vauxhall Astra, and in addition to good real-world fuel economy, offers tidy handling and a long list of standard equipment. Just make sure you can live with its rather firm ride.

Read our full Seat Leon review >>


3. Vauxhall Astra 1.6 CDTi 110 Ecoflex

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How to buy your perfect Vauxhall Astra

True MPG 56.3mpg

In the past, we haven't rated the Vauxhall Astra particularly highly, but in its latest form the car is much more impressive. It has a lightweight construction which offsets the fact that most of its engines aren't as powerful as those you'll find in rivals. Plus, it's spacious and cheap to buy and run.

Read our full Vauxhall Astra review >>


2. Suzuki Celerio 1.0

2018 Suzuki Celerio 1.0 SZ4 auto

True MPG 57.8mpg

Despite being one of the cheapest new cars around until it was taken off sale in 2019, the Celerio came with a decent array of equipment, including air conditioning, a DAB radio and Bluetooth connectivity. The only engine option was a pretty lively 1.0-litre.

Suzuki Ignis 1.2 Dualjet SZ3

True MPG 59.6mpg

The SHVS version of the Ignis, which is front rather than four-wheel drive, is the most efficient car we've ever tested. It's a mild hybrid, which means a small electric motor works alongside its 1.2-litre petrol engine, helping to get you moving and reducing the strain on the engine. Even if you decide four-wheel drive is a must, the average True MPG only drops to 53.3.

Read our full Suzuki Ignis review >>


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