Outboard Protection at a Better Price

AMSOIL is fast becoming the standard in the 2-stroke outboard oils just based on performance. Several OEM’s have a niche requirement for 2-cycle oil that often scares the customer into believing the OEM recommended oil is the only safe choice. While there are many inferior products out there, you can be assured AMSOIL will always be at the front of the technology. And Sioux Falls Marine owners of ALL makes and models will benefit. Make the Synthetic Warehouse your HQ for all your marine lubricants. Although the AMSOIL HP Marine 2-Cycle Injector Oil is covered here, all of our marine two stroke oils perform with the same “built to outperform” commitment.

AMSOIL products are warranty secure so you can rest easy that our products will not cause issues with service requirements in and out of warranty – Guaranteed! Often our product will


The various departments at AMSOIL also work to stay ahead of the equipment trends, OEM requirements and prepare years in advance for specific EPA driven emission requirements well before it’s required for the manufacturer to make the change.

Marine E-TEC™ Field Study

AMSOIL HP Marine Synthetic 2-Stroke Oil provides excellent protection in Evinrude® E-TEC marine engines programmed to the lean-mix setting.

Two Cycle Test Overview

Evinrude® E-TEC™ marine engines are unique in that they offer an alternative, lean-mix setting that allows the engine to use less oil. Whether programmed to operate at the standard mix ratio or reprogrammed to the lean-mix setting, E-TEC engines use sophisticated electronic equipment to monitor conditions, including rpm and throttle position, to determine the appropriate gas-to-oil mixture. To use the lean-mix setting, however, customers must have their engines reprogrammed by an Evinrude dealer and agree to use Evinrude XD100™ oil exclusively, often at a higher cost compared to other oils. Bombardier Recreational Products (BRP®), the manufacturer of Evinrude E-TEC engines, has not established a performance specification against which to qualify other oils.


Determine through real-world field validation if AMSOIL HP MarineTM Synthetic 2-Stroke Oil meets the increased performance needs of reprogrammed Evinrude E-TEC engines operating on the lean-mix setting. Further determine if consumers can safely use HP Marine Synthetic 2-Stroke Oil in E-TEC applications in place of Evinrude XD100 2-Cycle Oil.


In conducting this field study, AMSOIL partnered with SEA-TOW®, a marine rescue organization specializing in non-emergency calls for assistance. Based in Naples, Fla., SEA-TOW typically tows large marine vessels, including yachts and sport cruisers. The engines that power their towing vessels routinely encounter heavyduty, high-stress operation and provide the ideal environment for testing motor oils. Both Evinrude 250 hp E-TEC engines used in the study were initially operated on the standard oil injection setting for 28 hours. An Evinrude dealer then reprogrammed both engines to operate on the lean-mix setting for the duration of the study. The starboard engine’s oil reservoir was filled with AMSOIL HP Marine Synthetic 2-Stroke Oil, the portside engine’s oil reservoir with Evinrude XD100 2-Cycle Oil. The validation period lasted a total of 534 hours; approximately 240 hours were spent under severe-service conditions when the SEA-TOW boat towed marine vessels. The engines were closely monitored for the duration, and upon completion, both were disassembled and rated by a calibrated ASTM rater who evaluated each engine based on NMMA TC-W3 criteria for two-cycle marine engines. Merit ratings for each set of components (e.g. piston skirts, piston rings, etc.) were determined using the appropriate techniques and rating scales as defined in the Coordinating Research Council, Inc. Deposit Rating Manual No. 20. The evaluation included an examination of the condition of all engine parts. Some components received a merit rating based on a 1-10 scale, with 10 representing a component free of defects and 0 representing catastrophic distress. Others received merit ratings indicating the percentage of an area with defects (e.g. the percentage piston skirt area containing scuffing). The average merit rating of each group of components is shown in this study.

Note: Test results describe and represent the properties of two-stroke oils tested from February 2009 through April 2010. Results do not apply to any subsequent reformulations of such oils or to new oils introduced after completion of the testing.

And remember: Sioux Falls Marine owners of ALL makes and models will benefit from AMSOIL in cost and performance. Make the Synthetic Warehouse your HQ for all your marine lubricants. Gear, 2-cycle, 4-stroke and fuel system maintenance. Amsoil compared to expensive Evinrude XD100

Sioux Falls boaters save on 2-cycle Marine oil

The pistons in both engines received nearly identical high merit ratings for varnish, indicating both oils excelled at inhibiting varnish formation. Scratching refers to the alteration of the skirt surface in the form of sharp linear depressions from lapping of mating surfaces by fine particles suspended in the lubricant, fuel, air or embedded in a surface, while scuffing appears as a matte finish. The presence of scuffing is commonly lubricant-related. In both engines, scratching was present at trace to very light levels, represented by the low percentage ratings. Both oils completely prevented piston skirt scuffing, earning perfect ratings of 0.00 percent scuffing.

Amazing 2-cycle injector oil results

Deposits on the piston rings can cause ring sticking and consequent power loss. The top rings and second rings in both engines earned perfect merit ratings of 10.00, demonstrating no piston ring deposits. Merit ratings for crown land and second land deposits were similar for both engines.

Evinrude Head Deposits and Carbon

Excessive cylinder head deposits are undesirable and can negatively affect engine performance. Both oils earned high ratings for deposit control, indicating good cleanliness properties.

Evinrude piston crowns and undercrowns

While undercrown deposits do not impede performance, heavy piston crown deposits can cause preignition and consequent poor performance. Two-cycle oils must resist heavy deposit formation on the piston crown caused by the high temperatures inside the combustion chamber. HP Marine demonstrated strong performance in the area of piston crown deposits.


Connecting rod assembly components are exposed to elevated temperatures and pressures that can rupture the oil film, leading to metal-to-metal contact and wear. The wristpins, crankpin rod bearings and wristpin rod bearings in both engines demonstrated trace to light levels of wear and were found to be in “good” condition according to the calibrated ASTM rater. Deposits on all components were limited to levels not adversely affecting performance.

connecting Rods 2-cycle Evinrude ETEC

The wristpin and crankpin bearing races undergo constant rotational stress, inviting wear. Bearing races in both engines demonstrated trace to light levels of wear and were found to be in “good” condition according to the calibrated ASTM rater. Deposits were limited to low levels in both engines.

Cylinders - totally clean E-TEC

Carbon deposit buildup in the exhaust ports restricts air flow and can cause reduced power and poor overall performance. Both engines displayed virtually no exhaust port blocking, represented by the low percentages. Deposits were likewise minimal, with ratings near perfect 10s. In the area of cylinder bore scuffing, both oils limited metal-to-metal contact and achieved perfect scores of 0.00 percent. The cross-hatch pattern remains visible on the cylinder walls of both engines.

AMSOIL HP Marine Synthetic Two Stroke Oil

Evinrude XD100 2-cycle Synthetic Oil

The crankpins and main bearing journals experience elevated pressures during operation and represent common suffering points. In both engines, the crankpins and main bearing journals demonstrated trace to light wear and were found to be in “good” condition according to the calibrated ASTM rater. Ratings for deposits were nearly perfect for both engines.

Crankshaft Main Bearings Conditions

The main bearings experience intense pressure and represent a common area where metal-to-metal contact can occur. Both oils limited wear to trace to light levels and the bearings were found to be in “good” condition according to the calibrated ASTM rater. Both oils nearly eliminated deposits as well.


As demonstrated in real-world, severe-service testing, AMSOIL HP MarineTM Synthetic 2-Stroke Oil meets the stringent performance needs of Evinrude® E-TEC TM marine engines programmed for reduced oil consumption. Operated simultaneously with an engine lubricated with Evinrude XD100, an identical engine lubricated with HP Marine demonstrated strong performance and excelled in critical-component lubrication. The cylinder bores, for example, demonstrated 0.00 percent scuffing, while the main bearings demonstrated only trace to light wear. The engine also displayed no ring deposits, earning perfect merit ratings. Finally, HP Marine effectively limited deposits throughout the engine and met the increased performance demands required by the lean-mix setting. Results prove the effectiveness of AMSOIL HP Marine Synthetic 2-Stroke Oil in Evinrude E-TEC applications.

AMSOIL fully supports the use of HP Marine as a replacement for Evinrude XD100 in Evinrude E-TEC engines, and warrants its use according to the AMSOIL Limited Liability Warranty (G1363).