Does the color of the oil have any bearing on its lubrication ability?
A. No. Detergent oil will turn very dark, almost black in color after it is heated. Non-detergent oil will turn a reddish brown after it is heated. Most diesel engine lubrication oil will turn black in the first few minutes of operation due to the additive package in the oil and minute carbon particles. The only accurate way to determine the oil’s lubricating value or contamination level is through spectrographic oil analysis.
