Engine oil color reveals its age, contamination level, and operating condition. Fresh oil is amber or light brown. Oil darkened to black but still translucent after a few thousand miles is normal.

Engine oil turns black from a combination of combustion byproducts, heat oxidation, and detergent additives suspending carbon ...

Many car owners think oil only fails when the miles rack up. Wrong. Even when your ride sits for months, oil ages and degrade. Factors like exposure to condensation, temperature swings, and ...