Everything, even the smallest of things, can affect the performance of your engine. Whether topping off your fuel tank or driving on motor oil past its expiration date, you're slowly killing your car.

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.

When it comes to car maintenance, it can be easy to overlook oil inspection even when you have the best intentions. At a glance, oil checks might seem minor, but skipping out on this process can end ...