TECHNICAL DISCUSSION:
To protect the engine, the OEM has engineered the oil
pressure sensor to trigger the oil light when there is insuffi
cient oil pressure to maintain an adequate level of protection.
Each filter is equipped with a by-pass valve, so when
the filter is at or close to capacity, the engine is continually
supplied with adequate lubrication oil, although unfiltered.
However, if the filter reaches maximum capacity, the level
of restriction can become significant enough to trigger the
oil pressure warning light. In extreme situations, oil starvation
could occur.
Premature oil filter capacity can be attributed to a number
of factors such as poor air filtration, a leaking air intake
system or excessive contaminants being produced in the
combustion process. As discussed in the AMSOIL Technical
Service Bulletin Using AMSOIL in Engines with Possible
Sludge Issues,1 certain engines are prone to accumulate
sludge, including some engines from Toyota/Lexus.
RECOMMENDATION:
When used in conjunction with any Toyota/Lexus application,
or with the Pontiac Vibe featuring the 1.8L engine built
by Toyota, AMSOIL recommends changing EaO09 and
EaO10 Filters per the OEM-recommended change interval.
AMSOIL no longer recommends the EaO57 Oil Filter
for Toyota/Lexus applications, however, it is still recommended
for other applicable vehicle makes and off-road
equipment. Customers operating any of the above listed
applications with an EaO09, EaO10 or EaO57 Filter in
service beyond the OEM-recommended interval should
change the oil filter at the earliest opportunity. If the oil
light is triggered the filter should be changed immediately
to avoid damage. AMSOIL also offers WIX Filters as an alternative
to the Ea Filtration line and recommends the WIX
51348 Oil Filter for Toyota/Lexus applications that previously
called for an EaO57 Filter. If a WIX Oil Filter is used,
AMSOIL recommends changing it at OEM-recommended
intervals.