With petrol remaining above £1.50-a-litre and the nation still in the clasp of a cost-of-living squeeze, owning an economical car with low fuel bills is paramount for some drivers.
The problem is, you can’t always rely on the miles per gallon (mpg) figures car manufacturers quote in the showrooms, on their websites and in their TV ads.
That’s because ‘official’ tests to produce these figures are conducted in labs with unrealistic driving behaviour.
However, What Car? launched its own Real MPG database over a decade ago to tell motorists which of the latest vehicles truly are the most – and least – efficient.
Fuel economy figures you can count on: What Car? has revealed the 10 most and least efficient models it has put through its Real MPG tests.
And according to the consumer title, the most efficient model it has tested yet is a £25,000 Toyota crossover sold in showrooms today that is £1,100-a-year cheaper to fuel than the biggest gas guzzler it has reviewed.
The difference is the driving routes used to crunch the numbers are far more representative of British motoring habits with urban, rural and motorway sections included with more aggressive acceleration and braking than used in the official test.
This provides mpg figures motorists are more likely to see when they’re behind the wheel every day and driving as they normally would.
There is a separate ‘real range’ test for electric vehicles, meaning these aren’t included here.
And while regular hybrids are tested as part of the Real MPG database, plug-in hybrids – or PHEVs – are not listed because the figures for the latter vary dramatically depending on the distance you’re travelling and the amount of charge you have at the start of your journey.
With this in mind, What Car? has revealed which of the hundreds of models it has tested in recent years have the highest – and lowest – mpg results.
The most fuel efficient motor What Car? has tested so far is the £25,000 Toyota Yaris Cross. It returned an impressive 60.1mpg in the real-world economy measurements
The hybrid-powered Toyota Yaris supermini is the second most efficient model What Car? has tested so far, returning a mightily-impressive 59.9mpg
Not to be outdone by its Japanese rival, Suzuki’s Ignis 1.2 Dualjet Hybrid matches the Yaris with a 59.9mpg tested fuel economy
Skoda’s previous generation Octavia fitted with the 2.0 TDI (115hp) engine is great option for motorists looking for an economical family car. It returns 57.9mpg
Suzuki no longer sells the Celerio city car, which was one of the smallest models on the market when it was in showrooms. What Car? says the the 1.0-litre engine returns 57.8mpg
The best performing vehicle tested was the Toyota Yaris Cross 1.5 Hybrid, which recorded a Real MPG score of 60.1mpg, which works out (using current fuel prices) at just 11.2p of petrol per mile.
The runners-up were the Toyota Yaris 1.5 Hybrid and Suzuki Ignis 1.2 Dualjet Hybrid, which both managed 59.9mpg.
By contrast, the worst-performing vehicle tested was the Audi S8 performance saloon.
Given that it’s powered by a twin-turbocharged 4.0-litre V8 petrol engine, it’s unsurprising to see it achieved 21.7mpg under Real MPG conditions – an average fuel cost of 31p per mile.
The Audi S8 was followed by the Alfa Romeo Giulia Quadrifoglio – a rival in the hot saloon segment with a 2.9-litre twin-turbo V6 – returning a paltry 23.5mpg.
The Lexus LC Cabriolet – the naturally aspirated V8 petrol, not the hybrid sports car – is third from bottom with a 24.2mpg result.
Given that the average Real MPG across of all the 371 cars tested by What Car? is 42.3mpg, these represent a significantly larger fuel outlay.
We’ve listed below the best and worst performers in the Real MPG measurements, though not all cars are still available in showrooms and can only be purchases second hand today.
The biggest gas guzzler What Car? has tested yet is the Audi S8. The performance saloon manages just 21.7mpg from its twin-turbocharged 4.0-litre V8 petrol engine
The Audi S8 was followed by the Alfa Romeo Giulia Quadrifoglio – a rival in the hot saloon segment with a 2.9-litre twin-turbo V6 – returning a paltry 23.5mpg
The Lexus LC Cabriolet – the naturally aspirated V8 petrol, not the hybrid sports car – is third from bottom with a 24.2mpg result
Audi no longer sells this version of the SQ5. It was a mighty performance SUV but one that drank plenty of fuel, returning a measly 24.6mpg
The Mercedes-Benz S-Class Cabriolet S500 is no longer available in showrooms. When What Car? tested its fuel economy, it only managed to return 25.2mpg
Using the latest Department for Transport annual UK mileage figures – which show that the average mileage for petrol and diesel cars is 5,550 miles per year – combined with fuel pricing data, the Audi S8 has an annual fuel cost of £1,722.32, while the Toyota Yaris Cross Hybrid costs just £621.87.
Even within vehicle classes, making the right choice can add up to big savings.
In the popular family SUV market, for example, the gap between the best and worst performers was more than 28.1mpg, meaning drivers could save £657 in fuel costs each year by opting for a used diesel Renault Kadjar instead of the petrol Volvo XC40.
Steve Huntingford, What Car? editor, said: ‘There’s often a sizeable disparity between real-world driving efficiency and the official Government figures that car makers are obliged to publish.
However, our real MPG tests give car buyers realistic numbers to help inform their purchases.
‘As our figures show, by choosing carefully, it’s possible to save a lot of money in the long-term, particularly with fuel prices as high as they are today.’
