Investigation of Cold Start Operability, Long Term Impact, Emissions and Fuel Consumption of HVO Fuel in Volvo Car Engines and Vehicles

This study includes both engine and vehicle tests where HVO (hydrogenated vegetable oil) fuel was compared with diesel fuels. Cold start operability, long term impact on materials, emissions and fuel consumption were investigated. For the cold start tests the vehicle was cooled down for 10 h to selected temperatures and the time to start the engine was measured down to −27 °C. The tests showed that starting time was below 2 s down to −20 °C and there was no difference between the fuels. One car was operating 100,000 km on HVO fuel and the long term exposure showed neither negative impact on the materials nor high fuel dilution in the engine oil. Emission measurements were conducted in both test bed engine and vehicle. The test bed measurement showed that engine-out PM reduction is ~60 %, the NO_x emissions are similar and the specific fuel consumption is 4 % lower for the HVO fuel in comparison with European diesel fuel. The tailpipe CO₂, CO and HC emissions were reduced in the vehicle test by 6, 80 and 65 % respectively for the HVO fuel as a consequence of the higher hydrogen to carbon ratio.