AMSOIL 100% Synthetic 2-Stroke Injector Oil
AMSOIL 100% Synthetic 2-Stroke Injector Oil (AIO) is a dedicated injection-rate two-stroke lubricant built around full synthetic base oils for snowmobiles, outboards, personal watercraft, and other recreational two-stroke engines that specify API TC or TC-W3. The same formula is approved for use as an oil-injection feed or as a 50:1 pre-mix at 2.6 oz per U.S. gallon of gas, so a single shelf-stable jug covers the whole garage.
Wear protection at injection-rate metering
Modern oil-injected two-strokes meter only a few drops of oil per stroke, which leaves a very thin lubricating film between the piston, cylinder wall, and rod and crank bearings. AMSOIL Synthetic 2-Stroke Injector Oil is formulated with high lubricity and reliable film strength to protect against piston scuffing and bearing wear under that injection-rate film thickness, and the package is fortified with rust and corrosion inhibitors that protect ferrous surfaces in the wet, humid environments common to outboard service and stored snowmobiles.
Clean-burning detergency for direct-injection engines
Synthetic base oils burn more cleanly than conventional petroleum stocks, helping prevent the power-robbing deposits that build up on pistons, ring lands, and exhaust power valves in heavily-loaded two-strokes. The formula is fortified with high-temperature detergent and dispersant additives that resist ring sticking, ring jacking, and exhaust power valve sticking, supporting full compression and rated power across the duty cycle. The clean-burn behavior is the reason AMSOIL Synthetic 2-Stroke Injector Oil is positioned as ideal for direct-injection outboard motors, snowmobiles, and personal watercraft, where carbon and varnish on injectors and combustion surfaces are the primary failure modes.
Cold-temperature fluidity with a -60 F pour point
Cold-start protection is the defining requirement for snowmobile injector oils, because the oil pump has to draw and meter lubricant the moment the rope is pulled or the start button is pressed. AMSOIL Synthetic 2-Stroke Injector Oil carries a pour point of -60 F (-51 C) by ASTM D97, ensuring the oil flows quickly at startup so it reaches vital components before they take any dry-start damage. The same low-temperature behavior is reflected in the SAE J1536 Fluidity/Miscibility Grade 4 Arctic Climate rating (17,000 cP max at -40), which is the cold-flow benchmark for snowmobile two-stroke oils.
One formula across the powersports garage
The application table covers two-stroke outboards, snowmobiles, and other recreational two-stroke equipment that calls for API TC or TC-W3 oil, including engines from Arctic Cat, BRP, Evinrude, Force, Johnson, Kawasaki, Mariner, Mercury, Polaris, Sea-Doo, Ski-Doo, Suzuki, and Yamaha. That means the same quart bottle on the workbench can feed an oil-injected sled in January and a tiller-handle outboard in July, which simplifies inventory for owners who keep both. Owners of factory-lean Evinrude outboards should choose AMSOIL HP Marine Synthetic 2-Stroke Oil instead, which is the dedicated formula for that calibration.
Warranty Secure and AMSOIL Limited Warranty backing
AMSOIL Synthetic 2-Stroke Injector Oil is Warranty Secure, meaning installing it in place of a vehicle manufacturer-branded oil keeps the factory warranty intact under federal Magnuson-Moss rules. The product itself is backed by the AMSOIL Limited Warranty (G1363), which covers AMSOIL lubricants and filters when used as recommended.
Recommended applications and service intervals
Use as injection oil in stock oil-injected two-stroke snowmobiles, outboards, and personal watercraft that call for an API TC or TC-W3 oil, or as a 50:1 pre-mix at 2.6 oz per U.S. gallon of gas in the same applications and in pre-mix two-stroke equipment that accepts a TC or TC-W3 grade.
- Oil-injection rate: follow the engine builder's factory injection-pump calibration, which doses oil into the fuel charge automatically based on throttle and rpm.
- Pre-mix ratio: 50:1, equal to 2.6 oz of AMSOIL Synthetic 2-Stroke Injector Oil per U.S. gallon of gasoline, used in pre-mix engines and as the back-up ratio when an injection system is bypassed.
- Factory-lean Evinrude outboards: use AMSOIL HP Marine Synthetic 2-Stroke Oil rather than the Injector Oil grade.
- Engines requiring a specification other than API TC or TC-W3 (for example JASO FD, ISO-L-EGD, or a specific OEM premium injector oil): match the OEM call-out before substituting.
The formula is compatible with most conventional and synthetic two-stroke oils, but mixing oils shortens service life and reduces performance benefits, so refilling a tank with a single brand and grade is the recommended practice. Aftermarket two-stroke oil additives are not needed and are not recommended. For application-by-application application match on a specific sled, outboard, or PWC, use the AMSOIL Vehicle Lookup Guide.
Typical technical properties
| Property | Value |
|---|
| Kinematic Viscosity at 100 C, cSt (ASTM D445) | 6.6 |
| Kinematic Viscosity at 40 C, cSt (ASTM D445) | 32.9 |
| Viscosity Index (ASTM D2270) | 158 |
| Pour Point, C (F) (ASTM D97) | -51 (-60) |
| Flash Point, C (F) (ASTM D92) | 86 (187) |
| Fire Point, C (F) (ASTM D92) | 86 (187) |
| SAE J1536 Fluidity/Miscibility Grade | 4 Arctic Climate (17,000 cP max at -40) |
Order AMSOIL 100% Synthetic 2-Stroke Injector Oil
AMSOIL 100% Synthetic 2-Stroke Injector Oil is available in quart bottle (AIOQT-EA), case of 12 quarts (AIOQT-CA), gallon jug (AIO1G-EA), case of 4 gallons (AIO1G-CA), 55 gallon drum (AIO55-EA), and 275 gallon tote (AIO27-EA) sizes. Using AMSOIL synthetic lubricants does not void a new vehicle or equipment manufacturer warranty, and all AMSOIL lubricants and filters are covered by the AMSOIL Limited Warranty. Pick the right injector or pre-mix oil for a specific sled or class of riding with the AMSOIL Snowmobile Oil Guide, confirm application match for an outboard, PWC, or 2-stroke ATV using the AMSOIL Vehicle Lookup Guide, then order AMSOIL 100% Synthetic 2-Stroke Injector Oil.
Customer reviews
Best 2-stoke oil on the market
My 2001Yamaha 225 Vmax ox66 is 26 years old and still going strong. Have ran nothing but Amsoil from day one.
By Jeff from Oklahoma on April 30, 2026.
Would recommend this to a friend.
Great oil
Great oil. But be aware. The non stop send u emails. Way to many
By Mm from Pa on February 10, 2026.
Would recommend this to a friend.
2 stroke oil
Many years ago I was given a 9.9 Johnson two-stroke outboard motor because my friend said it smoked too much. I did all my normal tune-ups but it still smoked excessively. I tried new gas and different two stroke oils and additives but it didn't make a difference until I used Amsoil 2-stroke injector oil. After I ran through a couple of tanks of gas, the oil smoking dropped dramatically. Since this experience, I have used this oil in all my two-strokes and I am very happy with it's performance.
By John from Idaho on December 17, 2025.
Would recommend this to a friend.
Read all 50 reviews
Frequently asked questions
What is 2-stroke injector oil and how is it different from pre-mix oil?
Injector oil is a two-stroke lubricant designed to be metered into the engine by an oil-injection pump rather than pre-mixed into the gasoline. Injection-rate metering exposes the oil to a thinner film and to direct contact with hot combustion surfaces, so injector grades are formulated for clean burning and deposit control. AMSOIL 100% Synthetic 2-Stroke Injector Oil is approved for both injection use and 50:1 pre-mix at 2.6 oz per U.S. gallon of gas, so the same bottle covers both metering methods.
Which specifications and OEM applications does it cover?
The application table covers two-stroke outboard motors, snowmobiles, and other recreational two-stroke engines that require API TC or TC-W3, including those made by Arctic Cat, BRP, Evinrude, Force, Johnson, Kawasaki, Mariner, Mercury, Polaris, Sea-Doo, Ski-Doo, Suzuki, and Yamaha. Engines that call for a different two-stroke specification, such as JASO FD or ISO-L-EGD, should use a product that lists that specification in its application table.
What is the correct pre-mix ratio?
The recommended pre-mix ratio is 50:1, equal to 2.6 oz of AMSOIL Synthetic 2-Stroke Injector Oil per U.S. gallon of gasoline. The same ratio is used as the back-up mix when an oil-injection system has been bypassed or removed.
Is this the right oil for direct-injection snowmobiles, outboards, and PWC?
Yes. AMSOIL Synthetic 2-Stroke Injector Oil is positioned as ideal for direct-injection outboard motors, snowmobiles, and personal watercraft because the synthetic base oils burn cleanly and the additive package resists the carbon and varnish deposits that direct-injection engines are most sensitive to.
How well does it flow in cold weather?
The pour point is -60 F (-51 C) by ASTM D97, and the oil meets SAE J1536 Fluidity/Miscibility Grade 4 Arctic Climate at the 17,000 cP cold-pumping limit at -40. That cold-flow profile is what allows the injection pump to pull oil and meter it on the first revolution after a cold start, which is when piston-scuffing and dry-start damage are most likely.
Can it be mixed with conventional or other synthetic two-stroke oils?
The formula is compatible with most conventional and synthetic two-stroke oils, but mixing oils shortens service life and reduces performance benefits, so running a single brand and grade through the tank or injection reservoir is the recommended practice. Aftermarket two-stroke oil additives are not recommended.
Will running this oil void a factory snowmobile or outboard warranty?
No. AMSOIL Synthetic 2-Stroke Injector Oil is Warranty Secure, so using it in place of an OEM-branded oil does not void a new vehicle or equipment manufacturer warranty under federal Magnuson-Moss rules, and the product is backed by the AMSOIL Limited Warranty (G1363).
