Real MPG: most economical used cars

Our Real MPG tests show what fuel economy you can really expect from a car. Here, we reveal the most – and least – efficient used cars we’ve ever tested...

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by
Alasdair Rodden
Published28 May 2024

Depreciation is often the biggest cost you face when buying a new car. Even if you pick one of the slowest-depreciating cars on the market, you can still expect it to lose more than a third of its value over the first three years.

So, if you want to avoid this, you’re left with two options: lessen the blow with a big discount through our free New Car Deals service, or buy a used car instead.

However, having saved all that money, the last thing you want to find out is that you’re going to have to spend it all on fuel. So, we’ve looked at the data from our Real MPG tests to find the most economical used cars you can buy – that’s to say, those which you can no longer buy new.

Skoda Superb with Real MPG logo

The most frugal of the lot that we’ve tested is the Skoda Octavia family car, but this list also includes affordable small cars and even a hugelt spacious estate car.

If you’re thinking of buying a newer model, be sure to read our countdown of the most economical cars full stop.


How we test for a car’s Real MPG

The official NEDC and WLTP fuel economy figures that you’ll see printed in manufacturers’ sales brochures don’t reflect what you can actually achieve in the real world. Our Real MPG tests provide more dependable results because they’re based on a real-world driving route comprising town, motorway and rural sections, but they are conducted in a laboratory so the results aren’t affected by unpredictable traffic or weather conditions.

Each test car is weighed, and its tyre pressures are checked. Additionally, the interior temperature is set to 21 degC (or, if the car has manual air-con, the dial is set to the midway point), and all other electrical equipment – such as the headlights and stereo – are switched off.

An exhaust connection is used to measure the car’s emissions every second, and the resulting data is used to calculate its Real MPG.

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

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

Strengths

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

Weaknesses

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

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

There's now an updated Skoda Octavia, but the previous car is still a compelling family car choice if you're buying secondhand. As well as being particularly frugal when fitted with the 2.0 TDI 115 engine, the Octavia has a comfy ride and a good driving position. Plus, it offers a spacious interior and a massive boot, despite its saloon-like proportions.

However, it performed poorly in the latest What Car? Reliability Survey, with more than half of respondents reporting a problem with their Octavia.

Read our full used Skoda Octavia review

Strengths

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

Weaknesses

  • Cheap-feeling interior
  • Limited infotainment options

NEDC MPG 65.7mpg | Real MPG Average 57.8mpg | Town 47.0mpg | Motorway 53.3mpg | Rural 73.5mpg

The Celerio feels a little dated on the inside compared with the best used small cars, but it's a great choice if you're looking to maximise value for money. It's very affordable as a used buy, too, and it should cost you pennies to run, as our Real MPG data demonstrates.

On the move, the Celerio feels composed and secure, and it's surprisingly spacious in both the front and rear for such a little car.

Read our full used Suzuki Celerio 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

Strengths

  • Spacious interior
  • Relatively cheap to buy
  • Well equipped

Weaknesses

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

NEDC MPG 83.1mpg | Real MPG Average 56.3mpg | Town 46.4mpg | Motorway 50.7mpg | Rural 73.7mpg

When it launched in 2015, this generation of Astra was praised for being much better all-round than the 2009-2015 Vauxhall Astra it replaced. It's generally much more pleasant to drive (although it can be rather jiggly around town), and the 109bhp diesel engine we're looking at here should help keep running costs to a minimum.

Unfortunately, like the Skoda Octavia, the Astra is let down by a less-than-perfect reliability record – an important consideration when you're choosing a used car.

Read our full used Vauxhall Astra review

Strengths

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

Weaknesses

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

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

The VW Up is undoubtedly a small car, but one of its greatest strengths is that it doesn't feel like one when you're inside. There's oodles of space in the front (thanks in part to its boxy shape), and it feels much more grown-up to drive than its diminutive proportions would suggest.

As well as the frugal 59bhp engine in this version, the Up was available with a variety of more powerful 1.0-litre petrol engines at various points in its 11-year life, and there was even an all-electric model, called the Volkswagen e-Up.

Read our full used Volkswagen Up review

Strengths

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

Weaknesses

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

NEDC MPG 78.5mpg | Real MPG Average 56.0mpg | Town 46.3mpg | Motorway 50.9mpg | Rural 71.7mpg

The previous-generation Seat Leon is one of the best used family cars you can buy. It's great to drive, with sporty handling and a comfortable ride, and there's loads of room inside for people as well as stuff.

What's more, according to our Reliability Survey, the 2013-2020 Leon is one of the most reliable family cars around, and it is far less prone to faults than the current Seat Leon.

Read our full used Seat Leon review

Strengths

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

Weaknesses

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

NEDC MPG 62.7mpg | Real MPG Average 55.2mpg | Town 46.6mpg | Motorway 49.9mpg | Rural 70.4mpg

While the Baleno was available with two engines when new, the 109bhp turbocharged 1.0-litre petrol sold better and so is in more plentiful supply on the used market.

Fortunately, it offers peppy performance as well as good fuel economy. However, the rest of the driving experience is less appealing; the steering doesn't give much feedback, and the Baleno's soft ride means it leans quite a lot in corners. Interior space is impressive, though.

Read our full used Suzuki Baleno review

Strengths

  • Great to drive
  • Smooth ride
  • Cheaper than a Volkswagen Up

Weaknesses

  • Only four seats
  • Clumsy automatic gearbox
  • Volkswagen Up holds its value better

NEDC MPG 62.8mpg | Real MPG Average 55.2mpg | Town 45.9mpg | Motorway 50.0mpg | Rural 70.6mpg

You may be thinking the Skoda Citigo looks familiar – and you'd be right. It shares its underpinnings (and quite a few body panels) with the Volkswagen Up and, like its VW sibling, it's a brilliant small car. It's economical and fairly reliable, and some versions sit in insurance group 1, making the Citigo a good choice for new drivers.

The ace up the Citigo's sleeve, is the price; it usually undercuts the Up like-for-like, making it a very smart secondhand buy.

Read our full used Skoda Citigo review

Strengths

  • Spacious interior
  • Bigger boot than sibling Nissan Qashqai
  • Quiet petrol engines

Weaknesses

  • So-so quality
  • Grabby brakes
  • Choppy ride on big alloys

NEDC MPG 46.3mpg | Real MPG Average 55.2mpg | Town 50.0mpg | Motorway 48.8mpg | Rural 69.1mpg

The Renault  Kadjar is based on the hugely popular 2014-2021 Nissan Qashqai, yet it's shared little of its sibling's sales success. There's quite a lot to like about it, though.

The Kadjar is spacious by class standards – it has a bigger boot than the Qashqai – and it's fairly comfy, as long as you avoid cars fitted with 19in wheels. It's worth noting that Renault's reliability record isn't the best.

Read our full used Renault Kadjar review

Strengths

  • Class-leading space
  • High-quality interior
  • Excellent value used

Weaknesses

  • Diesels sound a bit gruff
  • Some rivals are more fun to drive
  • 2.0-litre petrols are quick, but rather thirsty

WLTP MPG 51.5mpg | Real MPG Average 54.8mpg | Town 45.8mpg | Motorway 49.5mpg | Rural 70.4mpg

The previous-generation Skoda Superb Estate scooped our Estate Car of the Year award eight years in a row, because it nails the estate car brief almost perfectly.

Its enormous boot is easy to access and is a practical shape, allowing it to swallow significantly more than any of its main rivals, and there's loads of interior space, too. The real-world fuel economy of the 2.0 TDI 150 diesel engine is the icing on the cake.

Read our full used Skoda Superb Estate review

Strengths

  • Comfortable ride
  • Engaging to drive
  • Huge boot

Weaknesses

  • Cheap-feeling plastics inside
  • Fiddly touchscreen
  • Some rivals offer better value

NEDC MPG 78.5mpg | Real MPG Average 53.7mpg | Town 47.7mpg | Motorway 47.0mpg | Rural 69.2mpg

It may not be anywhere near as popular as it was in its heyday, but the last of the Ford Mondeos still has a lot to offer the used executive car buyer. It's large and pretty spacious, and all but the hybrid version get a useful hatchback-style tailgate.

The Mondeo also handles well, and almost all variants are pretty comfortable.

Read our full used Ford Mondeo review


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And the least economical used cars...

Porsche Macan Turbo

If fuel economy is a priority, the diesel Macan is a better bet than this flagship model, which averaged 25.3mpg in our Real MPG test. Read our review

Mercedes S500 Cabriolet

The V8-engined S-Class Cabriolet is a luxurious drop-top with surprisingly sharp handling, a plush interior and a 25.2mpg thirst. Read our review

Audi SQ5 3.0 TFSI

This performance version of the Q5 is more powerful than the diesel version that replaced it, but you pay for this with a Real MPG of just 24.6mpg. Read our review