Your Next Diesel Engine Oil

Provided below is information provided by Amsoil, Inc., regarding inherent late model Ford, GM and Dodge diesel engine issues.

Issues:

AMSOIL has documented increasing levels of fuel contamination (fuel dilution) in the engine oil of 2007-2008 light-duty Ford, GM and Dodge diesel pickups, and indications are that 2009-2010 models are also affected. Research indicates fuel dilution is intensifying due to the use of in-cylinder post-fuel injection during the engine’s exhaust stroke to regenerate the diesel particulate filter (DPF). Fuel in the oil reduces the oil’s life expectancy and effectiveness. Because diesel fuel is a natural solvent, fuel dilution in motor oil causes a decrease in viscosity which may lead to an increase in engine wear rates.

Solution:

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Hard-working diesel engines present a serious challenge to the lubricants that protect them. Tight clearances and intense pressures can generate enough force to tear apart the molecular structure of the oil, causing permanent viscosity loss. Permanent viscosity loss is termed “shear” and leads to accelerated equipment wear, oil consumption and deposit formation.

Shear stability measures a lubricant’s ability to withstand shearing forces without degrading to a lower viscosity. To meet CJ-4 requirements for shear stability, the American Petroleum Institute (API) requires diesel oils to pass the Kurt Orbahn 90-Cycle Shear Stability Test. Resisting shear and maintaining protective viscosity in the harsh operating conditions of diesel engines is challenge enough for many diesel oils, but maintaining viscosity in the face of fuel dilution is another challenge altogether. Factors such as frequent starts, excessive engine idling, short trips and cold weather have contributed to moderate levels of fuel dilution in diesel applications for years, while recent issues with emission systems have brought the fuel dilution problem to a whole new level.

For example, AMSOIL has documented increasing fuel dilution levels in 2007-2009 Caterpillar C13 and C15 on-highway engines. There are many possible causes, including problems with a unit injector or leaking seals. Another cause of fuel dilution is new emission systems using in-cylinder post-fuel injection, a process most 2007-2010 light-duty GM, Ford and Dodge diesel pickups use to regenerate the diesel particulate filter.

Because diesel fuel is a natural solvent, it causes a multitude of problems when it contaminates the oil, including reduced oil viscosity, reduced oil fi lm strength, increased engine wear (particularly in the cylinder/ring area), increased volatility, weakened lubricant detergency, accelerated lubricant oxidation, varnish formation, acid formation/corrosion and low oil pressure.

The most notable problem associated with increased fuel contamination is reduced viscosity and the corresponding effect it has on oil performance. When combined with shearing conditions, as little as 4 percent fuel dilution is generally enough to reduce an oil’s viscosity to less than the specified viscosity grade.

AMSOIL sent five competitive synthetic CJ-4 5W-40 diesel oils to an independent laboratory for shear stability testing. Knowing the tough environment that diesels present to lubricating oils, AMSOIL doubled the standard Kurt Orbahn 90-cycle test and had the oils tested for 180 cycles. Samples were then contaminated with 2 and 4 percent ultra low sulfur diesel (ULSD) fuel. As the graph shows, even after being shear tested for twice the industry standard and contaminated with 4 percent fuel dilution, AMSOIL maintained viscosity and was the only oil to stay within an SAE 40 viscosity rating. As other oils lost viscosity due to shearing forces and fuel dilution, their ability to protect against wear was jeopardized.

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AMSOIL Premium Diesel Oils are formulated with an ultra shear stable polymer system that maintains viscosity better than inferior products. Testing proves that AMSOIL provides unsurpassed shear stability, offering better viscosity control than competitive oils.

Recommendations:

Although AMSOIL Premium Diesel Oils have shown the ability to maintain integrity under fuel dilution conditions, the abnormally high rate and unknown long-term effects have forced AMSOIL to adjust its drain interval recommendations as a precautionary measure in 2007-2010 Dodge 6.7L, Ford 6.4L and GM 6.6L LMM light-duty turbo-diesel pickups. In these applications, AMSOIL recommends changing AMSOIL Premium API CJ-4 Synthetic Diesel Oils (DEO, DME) at the manufacturer-recommended drain interval. Drain intervals may be extended further with oil analysis.

Amsoil DEO - link / Amsoil DME - link

AMSOIL previously announced a fuel dilution issue in 2007-2009 on-highway Caterpillar C13 and C15 engines that forced the company to adjust its drain interval recommendation in those applications to the manufacturer-recommended drain interval.

In all other applications, AMSOIL full synthetic diesel oils are recommended for three times (3X) the OEM recommendation, not to exceed 50,000 miles/600 hours or one year, whichever comes first, while Synthetic Blend 15W-40 Heavy Duty Diesel and Gasoline Motor Oil (PCO) is recommended for the longest OEM recommended drain interval. Drain intervals may be extended further with oil analysis.

Amsoil PCO - link

Related article: Does Syn Oil Lead to Salvation? - link

Manufacture & Dealer Information

AMSOIL INC., headquartered in Superior, Wisconsin., is a recognized leader in synthetic lubricant and filtration products since 1972 producing the first 100% synthetic motor oil to be recognized by the American Petroleum Institute (API).



For more information about AMSOIL synthetic lubricants and performance filtration products contact Anthony Garner at Competition Synthetics. Anthony is an Amsoil T-1 Certified Independent Dealer. E-mail Anthony at compsyn@live.com, or visit http://competitionsynthetics.com