HCNG

HCNG (or H2CNG) is a mixture of compressed natural gas and 4–9 percent hydrogen by energy. It may be used as a fuel gas for internal combustion engines and home appliances. HCNG dispensers can be found at Hynor (Norway) Thousand palms and Barstow,California, Fort Collins, Colorado (all US), Chongqing and Shanxi (China),Pico Truncado (Argentina),Islamabad (Pakistan),Dunkerque (France),Gothenburg Sweden, Rio de Janeiro (Brazil), Emilia-Romagna,Lombardia (Italy), Dwarka and Faridabad (Delhi), India and the BC hydrogen highway in Canada.

HCNG for mobile use is premixed at the hydrogen station.

...
Wikipedia