Abstract
The paper presents unique research results on the effect of coking of diesel engine injector nozzles powered by mixtures of 10%, 20% and 30% biomethanol and diesel fuel compared to the engine being supplied with pure diesel fuel. The test results, obtained from an experiment conducted in accordance with the ISO 15550-1 standard, show the legitimacy of using biomethanol as an additive to diesel fuel due to the lower coking effect of the injector nozzles, which has a positive impact on the reduction of pollutant emissions during engine operation. Regarding the CEC PF-023 test, the tendency to reduce the coking tendency increases the percentage of biomethanol additive to diesel fuel. With a 10% share of biomethnol, the average coking effect of the injectors is over 1% lower, but with a share of 30% of bio-methanol, the coking effect is nearly 2% lower.