Lower levels of nitrogen emissions have been measured from school buses fuelled with propane than from those using diesel , according to a study by the West Virginia transportation Center for Alternative fuels , Engines and Emissions . The buses were tested at various times during 2018 on a selection of bus routes . On a stop - and - go route , nitrogen emissions were up to 34 times higher from diesel engines than from those using propane fuel , while a city route recorded emissions up to 19 times higher . On the stop - and - go route , propane emissions cut nitrogen emissions by 96 % and CO2 emissions by 13 % .
Lower levels of nitrogen emissions have been detected from school buses fuelled with propane than from those using diesel, according to a study by the West Virginia University Center for Alternative Fuels, Engines and Emissions. The buses were tested at various times during 2018 on a selection of bus routes. On a stop-and-go route, nitrogen emissions were up to 34 times higher from diesel engines than from those using propane fuel, while a city route recorded emissions up to 19 times higher. On the stop-and-go route, propane fuel cut nitrogen emissions by 96% and CO2 emissions by 13%.