L/100km ↔ MPG (EU Perspective) Converter

Until the late 1970s, European fuel-economy claims were a patchwork. West Germany used litres per 100 km. The United Kingdom used MPG-UK on the imperial gallon. France quoted litres per 100 km but also flirted with kilometres per litre on some Citroen showroom posters into the 1960s. Italy used both, depending on the magazine.

German motoring culture made the decisive move. Auto Bild, launched in 1986, headlined every road test with the L/100km combined figure in big red type, with the arithmetic-mean comparison across all cars tested that month. The German federal consumer-protection law required L/100km in showroom literature from 1985. By the time the EU drafted its Energy Labelling Directive, L/100km was the obvious choice.

EU Directive 1999/94/EC, the "passenger car energy efficiency" directive, entered force on 18 January 2001. It required all new-car showroom labels to display fuel consumption in L/100km plus CO2 emissions in g/km. National variations - the German yellow energy-label sticker, the French A-G colour scale - all hung on the same L/100km backbone. MPG was relegated to a small-print conversion line in UK-spec brochures.

The 1996-2017 NEDC (New European Driving Cycle) was the dynamometer test that produced those headline L/100km figures. It was gentle - 11 km of stop-start driving, peak 120 km/h, no aircon, no realistic loads. Real-world economy ran 25-40 percent worse. The 2015 Dieselgate scandal at Volkswagen exposed how manufacturers gamed NEDC, and the European Commission accelerated the WLTP replacement.

WLTP (Worldwide Light-vehicle Test Procedure) took over from 1 September 2017 for new type approvals and 1 January 2019 for all new-car registrations. WLTP is 30 minutes covering 23 km, peaks at 131 km/h, includes realistic acceleration. Reported L/100km figures jumped 20-25 percent - same cars, harder test. Showroom posters now headline the WLTP number with an asterisk explaining the cycle.

EVs and PHEVs introduced new bookkeeping. EU energy labels for BEVs list kWh/100km plus an optional litre-equivalent figure (typically 1.5-2.5 L/100km gasoline-equivalent for a Renault Zoe or Tesla Model 3). The conversion assumes a fixed kWh-per-litre energy ratio, which critics argue understates grid emissions. The 2025 revision of the EU energy label tightened the PHEV utility factor, pushing PHEV L/100km headline figures from 1.5 to 2.5-3.5 to better reflect real-world plug-in behaviour.

By 2026, the EU has locked in Regulation 2023/851: new ICE passenger cars will not be registrable in EU member states from 2035. L/100km will become a legacy metric used mainly for used-car comparison and the residual ICE market. Pure-EV kWh/100km is taking over. But for the 80 percent of EU cars still burning liquid fuel as of 2026 - and decades of used-car listings stretching back to NEDC days - the cyan slider on this EU dashboard still tells the story. Lower number, less petrol, less money, less CO2.