Real MPG: The most economical cars revealed

What Car?'s Real MPG tests show what fuel economy you can really expect from a car. So, which models have the best mpg?...

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Alasdair Rodden
Published11 March 2024

Filling up with fuel is an expensive business right now, so if you're thinking of changing your car, there's a good chance that getting something more efficient is a high priority.

The trouble is that getting the best mpg from your car can be triky, because the official government fuel economy figures you'll see printed in sales brochures are often misleading, proving impossible to match in real-world conditions.

To help you get the best mpg, then, we carry out our own Real MPG tests, which show 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.

Here we're taking a look at the 10 most efficient cars we've ever tested, but if you're looking for the single most economical car we've ever tested, it's the Toyota Yaris Cross.

Read on to find out how we calculate your car's Real MPG, and see more of the cars which performed well in our tests.

How we test for a car's Real MPG

Our Real MPG tests take place in laboratory conditions on a rolling road to ensure that variables such as weather and traffic do not affect the results. This guarantees that our tests are repeatable. However, the cycle is based on a real-world route.

To ensure accuracy, we weigh every test car and check its tyres are correctly inflated before we begin. We then fit an exhaust connection to measure emissions.

The car's climate control is set to 21 degrees, or the midway point if it has manual air conditioning, with the fan speed set to its lowest setting. Additionally, we switch off all electrical equipment, including the headlights, heated seats, and stereo.

During the test, we monitor the car's tailpipe emissions every second. The Real MPG results displayed in this story are based on the average reading.

Read more: How we test a car's Real MPG

Our pick: 1.5 Hybrid Icon 5dr CVT

0-62mph: 11.2 sec
MPG/range: 64.2mpg
CO2 emissions: 100g/km
Seats: 5
Boot: 460 litres
Insurance group: 11E
Buying & Owning


  • Very efficient
  • Lofty driving position
  • Uncluttered dashboard is easy to use


  • Could be more spacious in the back seats
  • Vocal engine when accelerating
  • Not as fun to drive as the Ford Puma

Official MPG 62.7mpg | Real MPG Average 60.1mpg | Town 103.3mpg | Motorway 45.5mpg | Rural 70.5mpg

Take the ultra-efficient 1.5-litre petrol engine and electric motor from the Toyota Yaris, then stick it in a car with chunkier styling, and the result is the Yaris Cross. To many people, its small SUV dimensions will instantly make it more desirable. And, thanks to a bigger battery, it can actually go farther on electric power than its hatchback sibling.

Indeed, the Yaris Cross is the most efficient car we've ever tested, not only averaging more than 60mpg, but managing a staggering 103.3mpg in the urban part of our test. If you're looking for the best mpg car on this list, the Yaris Cross is it.

Read our full Toyota Yaris Cross review

Our pick: 1.5 Hybrid Design 5dr CVT

0-62mph: 9.7 sec
MPG/range: 68.9mpg
CO2 emissions: 91g/km
Seats: 5
Boot: 286 litres
Insurance group: 14E


  • Excellent real-world fuel economy
  • Toyota's reliability record
  • Slow predicted depreciation


  • Firm ride, especially on higher-spec models with bigger wheels
  • Poor rear passenger space
  • So-so interior quality

Official MPG 68.8mpg | Real MPG Average 59.93mpg | Town 80.0mpg | Motorway 46.7mpg | Rural 74.1mpg

Hybrid cars don't come any cheaper than the latest Toyota Yaris, yet it's also exceptionally frugal, having only been beaten by its Yaris Cross sister in our testing. Add in perky performance and the peace of mind offered by Toyota’s excellent reliability record, and it's easy to recommend. However, for those who often travel fully laden, small car rivals such as the Honda Jazz and Volkswagen Polo offer more space for rear passengers and luggage.

Read our full Toyota Yaris review

Our pick: 1.2 Dualjet 12V Hybrid SZ-T 5dr

0-62mph: 12.7 sec
MPG/range: 56.9mpg
CO2 emissions: 112g/km
Seats: 4
Boot: 260 litres
Insurance group: 21D
Buying & Owning


  • Good fuel economy
  • Spacious for a small car
  • Generous equipment


  • Ride can be fidgety
  • Vague steering
  • Poor infotainment system

Official MPG 55.7mpg | Real MPG Average 59.9mpg | Town 51.3mpg | Motorway 53.3mpg | Rural 74.8mpg

This version of the Ignis SUV is a mild hybrid, which means a small electric motor works alongside its 1.2-litre petrol engine to help get you moving more efficiently and reduce the strain on the engine – and our results suggest it does a pretty good job.

If maximum efficiency is what you’re after, you’ll want to stick with this front-wheel-drive version, but even if you decide four-wheel drive is a must, the average Real MPG only drops to 53.3mpg.

Read our full Suzuki Ignis review

Our pick: 1.5 TSI 150 SE L 5dr

0-62mph: 8.5 sec
MPG/range: 53.3mpg
CO2 emissions: 121g/km
Seats: 5
Boot: 600 litres
Insurance group: 21P


  • Comfortable ride
  • Enormous boot
  • Plenty of rear-seat space


  • Ride can sometimes be a little too floaty
  • Fiddly touchscreen
  • Some rivals are more refined
  • Reliability can be an issue

Official MPG 64.8mpg | Real MPG Average 57.9mpg | Town 50.5mpg | Motorway 52.1mpg | Rural 72.6mpg

If you cover enough annual miles to justify having a diesel engine, then this 2.0-litre unit in the Skoda Octavia will save you a bundle on running costs. The Octavia is a seriously impressive family car in other respects, too; its boot dwarfs that of every other car in this top 10, and it’s a great place to be, with a spacious interior and a plush ride. Unfortunately, this engine is no longer available, but there are plenty of examples on the used market.

Read our full Skoda Octavia (2020-present) review


  • Cheap to run
  • Spacious by class standards
  • Reliability record


  • Cheap-feeling interior
  • Limited infotainment options

Real MPG Average 57.8mpg | Town 47.0mpg | Motorway 53.3mpg | Rural 73.5mpg

Despite being one of the cheapest new cars around until it was taken off sale in 2019, buyers of a Celerio in mid-range SZ3 trim were treated to a decent array of equipment, including air conditioning, a DAB radio and Bluetooth connectivity.

The 1.0-litre petrol engine we tested was the only one you could get in the Celerio, but that’s no bad thing – it’s quiet and smooth, as well as being the most frugal petrol engine we’ve tested which does without any hybrid assistance.

Read our full Suzuki Celerio (2016-2019) review

Our pick: 1.2 Turbo 130 GS 5dr

0-62mph: 9.7 sec
MPG/range: 52.3mpg
CO2 emissions: 123g/km
Seats: 5
Boot: 422 litres
Insurance group: 19E


  • Spacious interior
  • Relatively cheap to buy
  • Well equipped


  • Vague steering
  • Diesels can be noisy
  • Low-speed ride can be fidgety
  • Reliability mixed

Real MPG Average 56.3mpg | Town 46.4mpg | Motorway 50.7mpg | Rural 73.7mpg

For a long time, we didn't rate the Astra particularly highly, but this was the generation that changed that. It had a lightweight construction, which helped efficiency, and managed to be more spacious inside than its predecessor whilst becoming smaller on the outside.

And, as well as being cheap to fuel, the 1.6-litre diesel engine we tested was the cheapest of the three on offer when it was new, so used prices are tempting. These Astras do have a less-than-perfect reliability record, though.

Read our full Vauxhall Astra (2015-2021) review



  • Spacious interior with flexible rear seats
  • Lots of standard equipment
  • Slow depreciation


  • Very pricey by small car standards
  • Not the quietest cruiser
  • Some rivals are more fun

Official MPG 61.4mpg | Real MPG Average 56.0mpg | Town 68.8mpg | Motorway 43.4mpg | Rural 73.0mpg

The Jazz's party piece is its practical interior. No other small car can offer rear seat occupants as much space as the Jazz and, when those seats are vacated, they can be flipped up to create a second, vast boot space. The Jazz is also very well equipped, and pretty comfortable on the move. As with the Yaris Cross and Yaris, the key to its efficiency is its hybrid system, that can run the car purely on electric power for short distances.

Read our full Honda Jazz review


  • Good to drive
  • Well equipped
  • Cheap to buy and run


  • Firm ride
  • Not as refined as some rivals
  • Bland interior

Real MPG Average 56.0mpg | Town 46.3mpg | Motorway 50.9mpg | Rural 71.7mpg

The Leon is Seat's answer to the Ford Focus and Vauxhall Astra, and this previous-generation version makes a fantastic used buy. In addition to its impressive real-world fuel economy, the Leon offers tidy handling – although it’s pipped by the Focus for all-out fun factor – and a long list of standard equipment, for a reasonable price. The trade-off for its sporty character is a rather firm ride, but if that doesn’t bother you, the Leon won’t disappoint.

Read our full Seat Leon (2013-2020) review


  • Comfortable ride and fun to drive
  • Economical three-cylinder engine
  • Upmarket interior


  • Some rivals are better value
  • Smaller engines are sluggish
  • Optional automatic gearbox is slow and jerky

Official MPG 50.7mpg | Real MPG Average 56.0mpg | Town 44.3mpg | Motorway 51.9mpg | Rural 72.2mpg

It's been around for a while, but the Up remains a solid choice if you're in the market for a small car, thanks to its smart interior and fun handling. This 1.0-litre petrol engine may only have 59bhp, but that’s still plenty of pep for city streets. You'll quickly feel out-matched on the motorway, though. The Up has now been removed from Volkswagen's new car line-up, but there are plenty of examples available on the used market.

Read our full Volkswagen Up (2012-2023) review


  • Comfortable ride
  • Spacious interior and boot
  • Affordable buying and running costs


  • Vague steering
  • Flimsy feeling interior
  • Unrefined and noisy at speed

Real MPG Average 55.2mpg | Town 46.6mpg | Motorway 49.9mpg | Rural 70.4mpg

Sold between 2016 and 2019, the Baleno is a small yet practical hatchback that will also cost you a pittance to buy and run. You'd never describe it as fun to drive, with handling that’s competent, but not remotely engaging, although the Baleno does offer a pretty comfy ride. You can get a Baleno with one of two engines: the 1.0-litre petrol we tested, and a 1.2-litre mild hybrid, not dissimilar to the one in the Ignis.

Read our full Suzuki Baleno (2016-2019) review

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