AMSOIL 10W-30 Excels in API Sequence IIIF Test
The Sequence IIIF test is a stringent API SL, ILSAC GF-3
test designed to measure oil thickening and piston deposits in high temperature
service, as well as provide information on valve train wear. The test is designed
to emulate high-speed service under high ambient conditions.
OBJECTIVE
Subject AMSOIL 10W-30 Synthetic Motor Oil (ATM) to an independent API Sequence IIIF
Test to determine its effectiveness in preventing deposit formation and providing
wear protection in high temperature conditions.
SPECIAL CONDITIONS
Because AMSOIL is formulated to provide superior performance over extended drain
intervals, testing was allowed to continue for 240 straight hours, three times the
length of the standard Sequence IIIF test.
TEST PROCEDURE
Testing is conducted with a 1996 model Buick 3800 Series II, water-cooled, four-cycle,
V-6 engine. The test engine is an overhead valve design (OHV) with a single camshaft
operating the intake and exhaust valves through pushrods and hydraulic valve lifters
in a slider-follower arrangement, and it has one intake and one exhaust valve per
cylinder. Induction is performed through a modified GM port fuel injection system
with the air-to-fuel ratio set to 15:1.
Running unleaded gasoline, testing begins with a 10-minute initial oil leveling
procedure before slowly working its way up to test speed, temperature and load conditions.
Testing continues at 100 bhp, 3600 rpm and 155 C oil temperature for 80 hours with
oil checks performed every 10 hours. Kinematic viscosity increase and wear metals
(Cu, Pb and Fe) are evaluated at every 10-hour interval.
At the end of 80 hours, all six pistons are inspected for deposits and varnish,
camshaft and lifters are measured for wear and oil screen plugging is evaluated.
Sequence IIIF
Test Parameters |
AMSOIL 10W-30 (ATM)
Triple Length (240 hr.) |
API SL Limits
(80 hr.) |
|
Kinematic Viscosity, % Increase at 40 C |
90.42 |
275 max. |
|
Weighted Piston Deposit Rating |
4.51 |
4.0 min. |
|
Average Piston Skirt Varnish Rating |
9.50 |
9.0 min. |
|
Cam Plus Lifter Wear Average m |
11.8 |
20 max. |
|
Hot Stuck Rings |
0 |
None |
|
|
TEST RESULTS
Even at three times the standard test length, AMSOIL 10W-30 performed three times
better than the test limit in the area of kinematic viscosity increase, and it excelled
in all areas of the test. AMSOIL 10W-30 Motor Oil kept viscosity increase, wear,
deposits and varnish to a minimum. The pictures below demonstrate the superior protection
provided by AMSOIL Motor Oil throughout 240 straight hours of Sequence IIIF testing.
While conventional motor oils tend to thicken and lose their lubricating effectiveness,
AMSOIL Motor Oils are formulated to maintain their viscosities over extended drain
intervals. The results of the Sequence IIIF test clearly demonstrate the long drain
capability of AMSOIL 10W-30 Motor Oil. Even after being subjected to a triple length
Sequence IIIF test, AMSOIL 10W-30 performed three times better than the standard
test limits. The competitor's motor oil shows dramatic viscosity increase in less
than half the time.
The greatest overall load concentration and stress are placed on the piston skirts
and rings on the thrust sides of the pistons as they move down, contributing to
heavier deposits than the anti-thrust sides. Even after being subjected to the Sequence
IIIF test for three times the standard test length, the pistons (above) lubricated
by AMSOIL 10W-30 Motor Oil show minimal deposits and varnish. In fact, upon close
inspection, the original piston machine markings are still visible on both sides
of the pistons. This superior protection provided by AMSOIL Motor Oils extends the
lives of both old and new vehicles, even in severe driving conditions.
Even at three times the standard Sequence IIIF test length, the oil pan, screen
and valves showed no signs of deposits, oxidation or plugging. By keeping engines
clean and deposit-free, AMSOIL Motor Oils effectively reduce wear and keep engines
running smoothly for extended drain intervals.
