OBJECTIVE:
Communicate the discovery and cause of excessive fuel
dilution in 2007–2010 light-duty diesel pickups from Ford,
GM and Dodge and the resultant reduction in the drain
interval recommendation for AMSOIL Premium Diesel Oils
in these applications.
ISSUES:
AMSOIL has documented increasing levels of diesel fuel
contamination (fuel dilution) in the engine oil in 2007–
2008 light-duty diesel pickups from all major vehicle
manufacturers, and indications are that 2009 - 2010
models are affected as well.
Research indicates that 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 fi lter
(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.


Read more here: AMSOIL Technical Service Bulletin