Does engine oil become thinner or thicker with use?
2 Answers
With prolonged use, engine oil tends to become thicker. Below is relevant information about automotive engine oil: Functions of engine oil: Separating the surfaces of relatively sliding parts to reduce wear, carrying heat back to the oil tank and dissipating it into the air to assist the radiator in cooling the engine, and circulating carbon deposits, sludge, and worn metal particles from engine components back to the oil tank, flushing away dirt generated on the working surfaces of parts through the flow of the lubricating oil. Engine oil quality grades: SA, SB, SC, SE, SF, SG, SH, SJ, SL, SM, where "S" represents gasoline engine oil, and the subsequent letters indicate the grade. Diesel engine oil is denoted by "C", with the following letters from A to H also arranged in ascending order of grade.
I've been driving my old car for over a decade, and I've noticed that engine oil definitely gets thicker the longer you use it. Fresh oil poured into a new car is thin and flows easily, providing excellent lubrication. But after prolonged use, dust, metal particles, and oxidation processes make the oil thicker. I remember once forgetting to change the oil during a long trip—after nearly 10,000 kilometers, the engine noise was as loud as drumming. When I finally got it checked, the oil was as sticky as syrup. Now I make sure to change the oil every 5,000 kilometers. If the viscosity gets too high, lubrication suffers, leading to faster engine wear and unnecessary repair costs. Regular maintenance not only saves money but also extends the car's lifespan. It's just like exercising—small upkeep prevents big problems.
