Methane is a simplest hydrocarbon and is a gas with a strong greenhouse effect. Methane is emitted from the exhaust gas of passenger cars, among other hydrocarbons. This work examines the emission of methane from several European passenger cars. The impact of fuel (gasoline, diesel, compressed natural gas), of the emission technology/driving cycle (Euro1, Euro2, Euro3, Tax Incentives Euro4, Euro4 and some non European regulations) and of mileage on the methane emissions is studied in this work. For all the above parameters, the emission of methane, but also its percentage in the other hydrocarbons is analyzed. The results show a significant impact of all the above parameters on methane emissions.