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 particles in the fluid. Black oil is not automatically a sign of a problem ...

This may sound like something out of the original "CSI: Crime Scene Investigation" TV series, but you can tell a lot about engine health by pulling out the dipstick, reading the oil level, and ...