Swiss researcher Alessia Cesarini at Empa has built a prototype e-fuel unit that produces synthetic gasoline from CO2 and green hydrogen. Her process uses oligomerisation to convert ethylene or propylene into liquid fuel, achieving a research octane number of 95. The fuel is designed as a "drop-in" replacement for fossil fuels, requiring no engine modifications. Transport accounts for 47% of Switzerland's energy-related CO2 emissions, and an estimated two million combustion vehicles will remain on Swiss roads by 2040. Globally, 55% of cars are expected to still run on combustion engines by then.