Real-world fuel consumption of electric and plug-in hybrid cars: words vs facts

Electric vehicle manufacturers declare the range of their cars based on the WLTP test cycle, originally designed to test conventional vehicles. Even though it has been updated to include electric and plug-in hybrid cars, it often leads to unreliable figures

It is called “range anxiety”, and it is a real psychological condition that arises when drivers of electric vehicles see their battery charge dropping toward the psychological threshold of 20 percent while still far from their destination or from charging stations. It manifests as growing concern about being stranded on the roadside, leading to increasing nervousness and, in more severe cases, actual physical discomfort.

Not surprisingly, manufacturers in the sector have for years promoted their vehicles by emphasizing range more than performance or power—figures calculated using WLTP tests (“Worldwide Harmonised Light Vehicle Test Procedure”), the international laboratory standard used to measure consumption and emissions. Introduced in 2017, the procedure simulates four different driving phases at different speeds, lasts about 30 minutes, and takes into account optional equipment for each model.

In theory, the test should provide consumption data close to real-world values, forming the basis for range calculations. In reality, however, this is often not the case, as demonstrated by periodic tests conducted in Norway on electric vehicles entering the market.

Every year, both in summer and winter, the Norwegian Automobile Federation (NAF), in collaboration with the magazine “Motor”, organizes fleet tests conducted simultaneously on multiple vehicles driven along the same routes and under identical weather conditions. In practice, these are long convoys of electric cars driving one after another until their batteries are fully depleted. It is a demanding test, but one that accurately reflects real consumption and range, with the only variable being the driving style of each tester.

The winter 2026 test, starting from Oslo and covering urban roads, highways, and mountain sections with temperatures ranging from −8°C to −31°C, involved 25 of the newest electric vehicles on the market. None of them achieved the range declared by the manufacturer, with differences ranging from −29 percent to −46 percent.

Weather conditions and the need to heat the cabin clearly played a role in these results, but this is a requirement common to all types of vehicles and one that has a much smaller impact on range in conventional cars. The Norwegian test effectively confirmed the theory that electric vehicle range decreases by about 1 percent of the WLTP value for every degree below the reference temperature of 23°C, while also showing that “range anxiety” is not entirely unfounded.

Below is a summary table of the tests organized last January by NAF and “Motor”.

Plug-in hybrids do not perform better in terms of consumption

The large discrepancies between declared and real-world data observed in Norway for electric vehicles are also found in plug-in hybrid cars when it comes to fuel consumption. The Fraunhofer Institute in Karlsruhe, Germany, analyzed 981,000 vehicles produced between 2021 and 2023, showing that declared consumption figures are significantly lower than those recorded in real driving conditions using OBFCM tests (“On-Board Fuel Consumption Monitoring”).

This monitoring system, applied to vehicles registered in the European Union, anonymously records kilometers driven, fuel consumed, and the actual amount of electricity recharged during everyday use. In this context, the gap between WLTP and real consumption is strongly influenced by driver behavior. If the electric component is not used efficiently, differences can reach up to 300 percent.

This is particularly evident when vehicles are driven for long periods with depleted batteries, effectively using a plug-in hybrid as a conventional car—despite its higher weight due to the hybrid system.

The report also analyzed the share of electric energy usage, finding that it never exceeds 45 percent of the available capacity and tends to decrease as vehicle value increases, approaching zero in luxury models. Among the least-used plug-in hybrids in electric mode are Porsche models, while Toyota vehicles make the most use of their electric motors, although still for less than 43 percent of operating time.

Title: Real-world fuel consumption of electric and plug-in hybrid cars: words vs facts

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