Data from Honest John has revealed that the plug-in hybrid (PHEV) Toyota Prius was the most fuel efficient car, while Suzuki and Nissan produced the most efficient petrol and diesel cars.
More than 250,000 people shared their fuel economy figures, with Honest John compiling the figures to create a ‘Real MPG’ rating.
The Toyota Prius was the most fuel efficient PHEV, and car overall, with the 2017-2022 Prius 1.8 VVT-i PHEV achieving 133.5mpg.
This was followed by the Hyundai Ioniq 1.6 GDI PHEV, with 129.5mpg, with the 2014-2020 Audi A3 Sportback 1.4 TFSI e-tron placing third (107.3mpg).
The most efficient petrol car was the 2015-2019 Suzuki Celerio 1.0 DualJet, with drivers averaging 70.1mpg.
Suzuki completed the top three with the 2016-2019 Baleno DualJet (63.5mpg), and the 2017-2024 Swift 1.0 BoosterJet Hybrid, which was placed on the petrol list due to being a mild hybrid.
Non plug-in hybrid models achieved figures closer to petrol models, led by the 2021 Toyota Yaris Cross 1.5 VVT-i Hybrid, achieving 70.5mpg.
The 2020-onwards Toyota Yaris Hybrid came second (69.6mpg), while the 2021-2025 Suzuki Swace (which is a Toyota Corolla Hybrid underneath) achieved third place with 65.5mpg.
Nissan’s Micra dCi 90, produced from 2017-2022 was the most efficient diesel, with 69.6mpg.
Next was the Seat Ibiza 1.4 TDI Ecomotive (66.5mpg), and then the 2012-2025 Fiat Panda 1.3 MultiJet (66.4mpg).
David Ross, senior editor at Honest John, said: “Vehicle manufacturers use a standard process to arrive at MPG figures, known as the Worldwide Harmonised Light Vehicle Testing Procedure, or WLTP.
“While it is said to closely replicate real-world usage, it’s only in daily use when you can truly assess how economical a car really is, and the Real MPG data has shown us some clear differences between WLTP figures and those achieved by HonestJohn.co.uk readers.
“One thing is certain, though, and it’s that Japanese brands came out on top for Real MPG performance”
The least efficient car was the 2011-2016 Mercedes-Benz C63 AMG Coupe, with its 6.2-litre V8 returning just 17.5mpg.
Honest John hopes to soon launch ‘Real Range’, a ranking of real-world electric car range numbers, once enough data is available from electric vehicle owners.
