Does the color of oil have any bearing on its lubrication ability?
None whatsoever. Detergent oil will turn a dark blue-black after it is heated. Non-detergent oil will turn a reddish-brown. Most diesel engines will turn oil black in the first few minutes of running time because of the ashley additive in diesel fuel. The only accurate way to determining an oil’s lubricating value or contamination level is through oil analysis or a portable oil quality analyzer, such as the Lubri-Sensor Oil Quality Analyzer.
