What is euro4 motorcycle?

What is euro4 motorcycle?

Currently, Euro 4 limits place restrictions on the amount of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx). As well as reducing those totals, Euro 5 adds a limit on the amount of non-methane hydrocarbons in the exhaust, and that’s proving to be a particular challenge for engine designers. Feb 14, 2019