PT  - JOURNAL ARTICLE
AU  - Mikuš, Pavol
AU  - Breznická, Alena
AU  - Kohutiar, Marcel
AU  - Krbaťa, Michal
AU  - Jus, Milan
AU  - Kakošová, Lucia
AU  - Fekiač, Jozef
TI  - Experimental Investigation of the Effect of Fuel on Engine Oil Life
DP  - 2025 Dec 8
TA  - Manufacturing Technology Journal
PG  - 655--661
VI  - 25
IP  - 5
AID - 10.21062/mft.2025.068
IS  - 12132489
AB  - The fuel content of engine oil is a significant factor affecting its degradation processes, lubricating properties and overall service life, especially in the case of modern internal combustion engines equipped with turbocharging, direct injection and exhaust gas recuperation systems. This study analyzes the dilution of engine oil with fuel in diesel and gasoline engines of vehicles with different degrees of wear, represented by the number of kilometers driven. The main objective of the research is to identify the relationship between the fuel concentration in the oil and changes in its physicochemical properties, as well as the potential impact of this phenomenon on the service life of the lubricant and the suitability of the set replacement intervals. The fuel content was quantified using precise quantitative spectrometric analysis, which allowed comparing engine oil samples taken under different operating conditions, including hot and cold starts, urban and highway operation. The results obtained show that vehicles with higher mileage and higher frequency of cold starts exhibit significantly higher rates of oil dilution by fuel, which directly affects the reduction of its viscosity and lubricating ability. The findings of this study provide important insights for the development of recommendations in the field of engine maintenance, especially with regard to optimizing engine oil change intervals, in order to prevent excessive wear and damage to engine components due to lubricant degradation.