RATIONAL

A marine engine must take a lot of punishment.  Unlike a car, a boat is not gliding along a semi-frictionless surface; it constantly battles drag.  This means the engine must work harder at all times and is under a constant load.  Additionally, cooler engine temperatures, excessive idling, and "loading up" can adversely affect the life of a marine engine.  It stands to reason that a good oil may substantially increase a boats service life and reduce maintenance time and costs.

THE TEST

Yachting Magazine installed AMSOIL Synthetic 15W-40 Heavy Duty Diesel and Marine Oil, an 8" By-Pass oil filter, and an ASF-25 Full-Flow Oil Filter on the port engine of their Tiara 2700 "Pursuit" Sports Fisherman Boat.  The starboard engine used its usual conventional brand of 15W-40 oil and filter.  Both engines were 265 HP Volvo gas motors. 

 The test used periodic oil analysis as a gauge for how much war the two engines experienced.  Experts often call "the lifeblood of an engine."  If this is true, oil analysis is a blood test for an engine.  Oil analysis measures the amount of "erosion" engine parts undergo over a period of time by pinpointing the quantities of certain elements present in the oil.  Generally speaking, the greater the amount of metals, the greater wear.

The test ran 17 months for a total of 880 operation hours.  Initial samples (#1) were taken prior to the test to determine the engines' conditions.  These samples showed both engines had similar wear-patterns and histories.  Oil analysis samples in this test were drawn at the same time from each engine and analyzed by an independent lab (Analysts Maintenance Labs, Inc., Illinois).  The cumulative results are at the bottom of this page.   Graphs accompanying this article show results from the past 215 hours of the test.  

THE RESULTS

The test emphatically demonstrates that AMSOIL products extend the service life of an engine and its oil.

 During the 17 months of the test, the AMSOIL Synthetic Heavy Duty Diesel and Marine Oil was changed only once after it's first year and two months of service (at test's end, AMSOIL was still well-suited for use); the petroleum oil was changed two times.   Despite this fact, AMSOIL consistently outperformed its conventional competition in wear-metal reduction.

Percentage Total Solids (%TS):  The measure of total solids in the oil, including metal fragments, intake dirt, deposits, and other particles typically associated with engine wear.  Smaller figures indicate reduced wear.  Results show AMSOIL reduced total solids by 66%

Iron Wear Particles (Fe):  One of the most important "indicator" wear metal Iron particles in oil come from such sources as cylinder, liners, pistons, rings, valves, valve guides, and anti-friction bearings.  Smaller figures indicate less wear.  AMSOIL reduced iron particles in the oil by a total of 55% overall. 

 Copper Wear Particles (Cu):  Copper particles in the oil come from such sources as bearings, bushings, thrust washers, valve guides and oil cooler tubes.  Results show AMSOIL reduced copper particle levels by a total of 79% overall.

Aluminum Wear Particles (Al):  Aluminum particles in oil come from pistons, bearings, pump vanes, and thrust washers.   AMSOIL, reduced aluminum particle levels by a total of 68% overall.

CONCLUSIONS:

  1)  In most cases, AMSOIL reduced engine wear by at least a factor of two over competitor's petroleum lubricant and conventional filter.  The use of AMSOIL would significantly reduced maintenance and upkeep costs.  

2)  AMSOIL Synthetic 15W-40 Heavy Duty Diesel and Marine Oil lasted much longer and was in much better condition than the competition throughout the test.

3)  AMSOIL was changed once during the test; the petroleum was changed twice.  AMSOIL  was deemed still suitable for use after the test period; the petroleum oil required changing.  This indicates AMSOIL provides fewer oil changes, less waste oil (economically and environmentally desirable), and less time wasted changing oil. 

THE RAW DATA:

 Without a doubt, the best way to assess the condition of an engine is to tear it down.  But almost as good a tool for diagnosis is spectro chemical analysis, or oil analysis.   Since different parts of an engine are made of different metals, the presence of these particles in the oil can mean increased wear.   The chart below shows the raw data of oil samples from the Yachting Magazine study.  The top half represents oil samples taken from the (Starboard) engine using petroleum; the bottom half reflects samples taken from the port engine which used AMSOIL Products.  Each green line represents an oil change.   Both engines were run on petroleum just prior to the test of 100 hours to compare their wear patterns.   (Sample 1), which are fairly similar. Symbols: Fe (iron), Pb (lead from leaded fuel), Cu (copper, Cr (chromium), Al (aluminum), Ni (nickel), Ag (silver), Sn (tin), Mo (molybdenum). Cd (cadmium), Sb (antimony),, PC TS (% of total solids).