EGARDING THE USE OF AMSOIL SYNTHETIC MOTOR OILS in brand new or rebuilt four stroke
gasoline or diesel engines, it is recommended to operate the engine up to its first
normal drain interval with a petroleum motor oil.
There are two primary reasons for this recommendation:
- New engines or engine components generate high wear metals and generally
contain debris from machining and assembly. It is more beneficial to allow these
wear metals to collect in an inexpensive motor oil than to circulate throughout
the crankcase for extended periods in a synthetic motor oil. By operating the
vehicle to its first drain interval with a petroleum oil, these wear metals and
manufacturing debris collect in the oil and are then flushed out of the crankcase
when drained. This allows for a much cleaner operating environment for the synthetic
- Within the first miles of operation, if there are any defects in the assembly
or workmanship of the engine components, then they may be corrected before installing
the more expensive synthetic motor oil. Occasionally, rebuilt engines may have
re-machined components or materials which can sometimes be mismatched, resulting
in problems which will develop in a fairly short period of time. If excessive
oil consumption or any other problem is noted, it should be corrected prior to
changing to AMSOIL Synthetic Oil.
For racing applications, a synthetic motor oil can be installed right away. These
engines are frequently disassembled and rebuilt under more exacting conditions and
require the improved wear protection of a synthetic motor oil. Extended drains are
rare due to common contaminants such as fuel dilution and dirt entry, therefore we
would recommend oil analysis to determine the servicability of the lubricant.
The breaking-in of a two-cycle engine is essentially the wearing of the mating surfaces.
AMSOIL recommends the use of our two-cycle oils during the break-in period, however,
because our oils do such a good job at preventing wear, the break-in process may
take longer. Follow the manufacturer's recommendations for mix ratios and
equipment operation during break-in.
- AMSOIL Technical Service Bulletin: OT-2004-07-01