What are the substances in engine oil?

[Harmony]

Engine oil contains substances that are carefully proportioned additives blended by engineers. Engine oil, also known as engine lubricant, consists of two main components: base oil and additives. The base oil is the primary constituent of the lubricant and serves the following functions: 1. Cooling and temperature reduction; 2. Sealing and leak prevention; 3. Cleaning and purification; 4. Shock absorption and cushioning; 5. Lubrication to minimize wear; 6. Rust and corrosion prevention; 7. Component protection. The method for changing engine oil is as follows: 1. Use a jack to lift the vehicle, locate the drain plug, and loosen it to drain the oil; 2. Remove the oil filter, place a container beneath it, and drain the old oil; 3. Install a new oil filter and add fresh engine oil.

[GabriellaLynn]

I've been repairing cars for over a decade, and engine oil may seem simple but has deep intricacies. Over 70% of it is base oil, divided into mineral oil (cheaper but shorter lifespan) and synthetic oil (more expensive but durable). The remaining 20% consists of precious additives: anti-wear agents act like liquid armor coating the gears; detergents function like tiny brushes cleaning sludge; viscosity index improvers prevent oil from thickening in cold weather or thinning in heat; antioxidants serve as preservatives against deterioration; anti-foam agents specifically tackle stirred-up bubbles. Last time, a car owner's engine still shook after an oil change. Upon disassembly, we found metal shavings – clearly the inferior oil's anti-wear additives couldn't withstand high temperatures and turned to debris. Switching to proper full synthetic oil immediately solved the issue.

[SanKathryn]

During car maintenance, technicians often say engine oil is the lifeblood of the engine. So what's in this 'blood'? Base oil makes up the bulk, like a soup base divided into bone broth (mineral oil) and chicken broth (synthetic oil). The key lies in the additive package: anti-wear agents are usually zinc-phosphorus compounds, forming a protective film on metal surfaces under high temperatures; detergents like alkylphenol amines specifically dissolve carbon deposits; viscosity modifiers such as polymethacrylates ensure flow even at -30°C. Once saw someone cheap out with a no-name brand oil—5,000 km later, sludge clogged the oil passages like sausages, costing 8,000 in major repairs. Penny wise, pound foolish.

[OFelicity]

I was shocked when I first learned about motor oil composition! Conventional mineral oil is directly refined from petroleum, semi-synthetic oil is blended with chemically synthesized components, and full synthetic oil is basically lab-created. The most amazing part is the additives: molybdenum offers three times better anti-wear performance than traditional zinc; borate detergents can dissolve turbocharger carbon deposits under high temperatures; silicone antifoam agents eliminate foam in just 1 minute. During my last high-altitude road trip, my friend's car using conventional oil suffered severe thermal breakdown, while my car with ester-based full synthetic oil had a noticeably smoother engine sound when climbing - the principle is that ester molecules remain more stable at high temperatures and can even repair microscopic metal surface scratches.

[BraydenFitz]

Engine oil formulations are more complex than perfumes! Mineral base oils are derived from crude oil distillation, while Group III hydrocracked oils perform nearly as well as synthetic oils. True full synthetics are Group IV PAO or Group V ester-based oils. Additives are even more intricate: ZDDP anti-wear agents protect camshafts but pollute catalytic converters, leading to the current popularity of phosphorus-free formulas. Organic molybdenum forms a slippery molybdenum disulfide film on metal surfaces, making engine sounds smoother. Remember a race car driver client who insisted on using 15W60 racing oil, resulting in 10 seconds of dry friction during winter startup that scored the crankshaft – for regular cars, 10W40 with titanium complex anti-wear additives is sufficient, as over-protection can actually harm the engine.

[LaHarrison]

My neighbor uncle always asks me: Why does black engine oil cost hundreds of dollars? Just look at the ingredients: Group III base oils are like craft beer ingredients—purer. Anti-wear additives include organic molybdenum (expensive but fuel-efficient) and zinc dialkyldithiophosphate (cheaper but contains phosphorus). Special mention goes to cold-start protection: The alkylnaphthalene viscosity modifier in 0W oil ensures pumping even at -35°C; ester-based oils have polar molecules that instantly adhere to metal during cold starts. Once during a winter rescue, I found a stranded car whose owner mistakenly used agricultural diesel oil—it congealed like lard in the cold and burned out the starter motor. Using the right oil is like buying insurance for your engine.