Oil color, lubrication ability and contamination level

It's a common misconception that an oil's color is an indication of how dirty it is.  This is absolutely NOT TRUE.  The color of an oil does not have any bearing on its lubrication ability*.  Most oil and especially diesel engine oil will turn black in the first few hours of operation due to contaminates generated by the combustion process and soot particles. 

The only way to accurately determine an oil's lubricating value or contamination level is through oil analysis.  Oil analysis is common practice used regularly in commercial, industrial and fleet operations and can also be used for passenger cars, light trucks or any other application. Oil analysis will also determine the exact parts per million(ppm) of wear metals in your oil which provides an indication of any abnormal wear or specific components that need mechanical inspection in addition to checking for any fuel, water or glycol contamination.
(what oil analysis testing checks for)

The useful life of an engine oil is dependent on several factors such as the quality of the oil, type of fuel, equipment condition, type and operating environment of the equipment and, most important, the type of filtration used. 

The filtration system and the oil are vital tools for preserving engine life.  A highly efficient filter is essential to protect an engine by removing both liquid abrasive contaminants held in suspension by a high quality premium oil such as AMSOIL. When using AMSOIL Synthetic Lubricants for extended drain intervals the AMSOIL Super Duty Filter must be changed at 12,500 miles or 6 months for gas engines and 7,000-10,000 miles or 6 months for diesel engines, such as the Ford Powerstroke, Dodge Cummins or Chevy Duramax, or as oil analysis indicates.

If the AMSOIL Dual-Gard or Dual-Remote By-Pass Filtration Systems are used then the AMSOIL Super Duty full flow engine oil filter must be changed at the same intervals as specified above and the by-pass filter(s) changed as indicated by oil analysis results.  The oil does not need to be changed when using by-pass filtration unless oil analysis testing indicates it is necessary.

It is not uncommon to go 100,00 miles or more on AMSOIL when using by-pass filtration. 
A Mack Dealership recently performed a teardown inspection on a 1990 Mack E7-400 diesel engine with 630,000 miles total and  409,000 miles without an oil change. Its parts were examined by an engine rater from a major oil additive raw materials manufacturer and supplier.

The engine showed light to moderate wear throughout, just as an engine in similar service and lubricated with conventional oil changed at 15,000-20,000- mile intervals (as is common with over-the-road semi-trucks) would show. In fact, according to the engine rater the parts examined- cylinder liners, pistons, rings, bearings, valve train components- could have been put right back in the engine and would have continued to provide the good, dependable service they had provided all along.

For the full story and pictures see 409,000 miles without an oil change. 

AMSOIL Synthetic Lubricants are designed and engineered for extended drain interval service.  The color the AMSOIL on your dipstick (or any oil for that matter) has absolutely no bearing on whether or not the oil is suitable for continued use or if it should be drained and replaced. Use the recommended change intervals for both the oil and engine oil filters as specified by AMSOIL.

*Note: The following are some indications of oil or filtration problems:

• When rubbing oil between your finger, you feel grit

• Milkshake appearance of your oil

• Fuel or coolant smell from your oil

Oil Analysis Report Items Include:
(How do I do an oil analysis)

• sample #, date sampled, date tested, unit #, engine make, model, year, oil brand, viscosity grade, sump capacity, make up oil added, type of filtration, last filter change

• component miles, oil miles, last oil change miles

•  % presence of gylcol, water, fuel

• viscosity @40 deg. C. and at 100 deg. C.

• % solids

• soot, oxidation %, NOX %, TBN, TAN

• % iron, chromium, lead, copper, tin, aluminum, nickel, silver, manganese, silicon, boron, sodium, magnesium, calcium, barium, phosphorous, zinc, molybdenum, titanium, vanadium and cadmium

• recommendations and additional test results