Synthetic and Regular Motorcycle Oil Comparison
The quest for synthetic motor oil came about because of the desire
to have the use of a non-petroleum based oil that performed better.
During World War II, the United States and Germany began researching
the idea of synthetic motor oil. In Germany, Dr. Herman Zornteri of
I.G. Farben Industrie was the first scientist to perform this type of
research. In the United States, Dr. W.A. Zisman of the Naval Research
Laboratory was testing these types of lubricants. Both sought oils that
were less apt to produce gel or gum in engines, while a major thrust
for German research was the desire to be less dependent on petroleum,
which was becoming less available as the primary source of energy
driving the country’s war machine.
The research centered on vegetable-based oil, such as banana oil. In
addition to fewer tendencies to gel or gum, oil with non-petroleum base
produced easier winter starting in gasoline engines in the U.S. Air
Force research and left fewer soot deposits in the oil radiators of the
engines under observation.
In the years after World War II, synthetic oils have enabled
consumers to achieve better fuel economy in some applications;
experience less loss due to evaporation; achieve better high and low
viscosity; realize less stress under high temperatures; avoid some
oxidation and oil sludge problems; and achieve better cold starting.
This is in addition to improved fuel economy.
Potential hazards of synthetic oil include caution during
new-vehicle break-in periods due suspected to lower friction
characteristics in some blends; some decomposition (limited to
industrial applications); and problems in some older racing engines
with roller lifters where the lifters may not function as well. Certain
plastics also may crack in the presence of synthetic oils.
True synthetic motorcycle oil is based primarily on non-mineral
sources. However, the United States allows oil that has been modified
using certain manufacturing processes with the addition of particular
chemicals to be classified as synthetic, and are known as “Class III”
synthetics. “Synthetic blends” are partially synthetic oils that are a
blend of mineral and vegetable-based oils, but are less than 30%
synthetic. These oils provide some of the advantages of synthetic oils
but cost less.
Harley-Davison Motor Company until recently advocated using only
natural, non-synthetic oil in its V-twin motors. This was because it
was thought the heat generated by these air-cooled engines was not high
enough to merit concern. However, with the introduction of H.D.’s
“Screamin’ Eagle” synthetic oil, the company has joined the ranks of
synthetic oil manufacturers who claim synthetic oil has advantages over
petroleum oil, including better heat dispersion in air-cooled engines.