Biodiesel Impact on Diesel Engine Performance

Biodiesel, typically derived from vegetable oils or animal fats and composed of fatty acid methyl esters, is increasingly adopted as an alternative or blend component to conventional diesel fuel. Its physicochemical properties—higher viscosity, oxygen content and altered cetane number—modify combustion characteristics, leading to enhanced fuel–air mixing and more complete oxidation. As a result, carbon monoxide and particulate emissions are substantially reduced, although nitrogen oxide formation often increases. On the performance side, slight penalties in power output and brake thermal efficiency have been reported at high blend ratios, alongside improvements in lubricity that can extend injector and pump life. The oxygenated nature of biodiesel also affects spray atomisation, ignition delay and combustion phasing, which may necessitate calibration of injection timing and pressure. Long-term use has highlighted challenges in material compatibility, cold-flow behaviour and deposit formation in injection systems and combustion chambers. Nevertheless, moderate blends (up to 20 per cent by volume) have demonstrated a balance between environmental benefits and minimal performance compromise. As decarbonisation of transport gains urgency, understanding these trade-offs is essential for integrating biodiesel into existing fleets and for designing engines optimised for renewable fuels.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Biodiesel Impact on Diesel Engine Performance publication trend

The graph below shows the total number of articles in biodiesel impact on diesel engine performance across all publications each year (not limited to Nature Index journals).

Technical terms

Fatty acid methyl esters (FAME): Biodiesel molecules produced by transesterification of fats or oils with methanol.

Cetane number: A measure of fuel ignition quality; higher values indicate shorter ignition delay.

Brake thermal efficiency: The ratio of useful mechanical work output to the energy content of the fuel consumed.

Lubricity: The ability of a fuel or oil to minimise friction and wear between moving surfaces.

Tribology: The science of friction, lubrication and wear in interacting surfaces.

Kinematic viscosity: A measure of a fluid’s resistance to flow under gravity, affecting atomisation and film formation.

References

1. Assessment of the Impact of Lubricating Oil Contamination by Biodiesel on Trunk Piston Engine Reliability. Energies (2023).
2. Modeling of Diesel Engine Fuel Systems Reliability When Operating on Biofuels. Energies (2022).
3. Applications Characteristics of Different Biodiesel Blends in Modern Vehicles Engines: A Review. Sustainability (2021).