Short answer
At 50:1, mix 2.6 oz. of 2-stroke oil per U.S. gallon of gasoline (20 mL per litre). Find the ratio and the oil standard in the engine manual: handheld equipment usually calls for JASO FD or ISO-L-EGD, water-cooled outboards for NMMA TC-W3, and snowmobiles, dirt bikes and ATVs for API TC or JASO FD. Never put 2-stroke oil in a four-stroke crankcase.
2-stroke oil mix chart
Measure the oil, do not guess it. The chart covers the common ratios in U.S. ounces per gallon and in millilitres per litre. A 2-cycle engine and a 2-stroke engine are the same thing, so 2-cycle mix charts and 2-stroke charts read the same way.
Use the ratio in the engine manual or the one the oil’s data bulletin permits for that engine. Too little oil risks seizure; far too much fouls plugs and leaves deposits.
| Ratio | 1 gallon | 2.5 gallons | 5 gallons | Per litre |
|---|---|---|---|---|
| 24:1 | 5.3 oz. | 13.3 oz. | 26.7 oz. | 42 mL |
| 32:1 | 4.0 oz. | 10.0 oz. | 20.0 oz. | 31 mL |
| 40:1 | 3.2 oz. | 8.0 oz. | 16.0 oz. | 25 mL |
| 50:1 | 2.6 oz. | 6.4 oz. | 12.8 oz. | 20 mL |
| 100:1 | 1.3 oz. | 3.2 oz. | 6.4 oz. | 10 mL |
How to mix 2-stroke gas and oil
Use fresh gasoline of the octane the manual specifies, and mix in an approved container. Add the oil, then the fuel, cap it and shake before every fill. Label the container with the ratio and date so mixed fuel is not used in a four-stroke engine.
Mixed fuel ages like any gasoline. Mix only what you will use in the next few weeks, or treat it with a stabilizer approved for two-stroke fuel.
Premix or oil injection
A two-stroke engine burns its lubricating oil with the fuel. Premix engines, such as chainsaws, trimmers and many dirt bikes and outboards, need oil mixed into the fuel at a set ratio. Oil-injected engines, such as most snowmobiles and many outboards, meter oil from a separate reservoir.
An injection system needs an oil suited to injection, and the reservoir must stay filled. Do not convert between the two unless the engine maker provides a procedure.
The standards on the label
API TC covers air-cooled and liquid-cooled two-strokes such as powersports engines. JASO FB, FC and FD are Japanese grades for detergency and smoke, with FD the highest; ISO-L-EGD is the equivalent international grade often specified for handheld equipment. NMMA TC-W3 is the standard for water-cooled outboards.
An oil may list more than one standard. Use one that lists the standard your manual requires.
Choosing an AMSOIL two-stroke oil
SABER Professional is listed for two-stroke handheld equipment where JASO FD, ISO-L-EGD or API TC oils are specified, including STIHL, Husqvarna and ECHO. AMSOIL’s bulletin says it may be used at conventional mix ratios or at the SABER Ratio regardless of the ratio specified for the equipment. If you prefer to follow your manual’s ratio, that use is also listed.
INTERCEPTOR is listed for two-stroke snowmobiles, motorcycles, ATVs and PWCs where API TC and JASO FD are specified, as injection oil or 50:1 premix. DOMINATOR 2-Stroke Racing Oil is for high-performance and modified engines that require API TC oil. 2-Stroke Injector Oil is listed for outboards, snowmobiles and other engines requiring API TC or TC-W3, as injection oil or 50:1 premix.
For outboards, HP Marine is listed for TC-W3 applications as injection oil or 50:1 premix, including Evinrude E-TEC and Mercury Optimax. 100:1 Pre-Mix Outboard Oil is listed for premixed outboards, PWCs and jet boats that specify TC-W3; its bulletin says to mix at 100:1 regardless of the equipment’s ratio, and permits richer mixtures.
| Product | Listed standards | Use |
|---|---|---|
| SABER Professional (ATPPK) | JASO FD, ISO-L-EGD, API TC | Handheld equipment, premix |
| INTERCEPTOR (AITQT) | JASO FD, API TC | Snowmobiles, motorcycles, ATVs, PWCs; injection or 50:1 |
| DOMINATOR 2-Stroke (TDRQT) | API TC | High-performance and modified engines; injection or premix |
| 2-Stroke Injector Oil (AIOQT) | API TC, NMMA TC-W3 | Outboards, snowmobiles; injection or 50:1 |
| HP Marine (HPMQT) | NMMA TC-W3 | Outboards; injection or 50:1 |
| 100:1 Pre-Mix Outboard (ATOBC) | NMMA TC-W3 | Premixed outboards, PWCs, jet boats |
Source: AMSOIL SABER Professional data bulletin G1987.
Source: AMSOIL INTERCEPTOR data bulletin G1955.
Source: AMSOIL HP Marine data bulletin G2987.
Source: AMSOIL 100:1 Pre-Mix Outboard Oil data bulletin G3295.
Sources checked . Prices and product guidance may change.
Frequently asked questions
How much 2-stroke oil per gallon for 50:1?
About 2.6 fluid ounces per U.S. gallon of gasoline, or 20 mL per litre.
Is 2-cycle oil the same as 2-stroke oil?
Yes, the terms mean the same thing. What matters is the standard on the label, such as JASO FD, ISO-L-EGD, API TC or NMMA TC-W3, and the ratio your engine needs.
What is the oil ratio for a 2-stroke outboard?
Use the outboard manual’s ratio and an NMMA TC-W3 oil. Many outboards are oil-injected and need no premix at all.
Can I use outboard TC-W3 oil in my chainsaw?
Use the standard your saw’s manual specifies. Handheld equipment usually calls for JASO FD or ISO-L-EGD, which TC-W3 alone does not cover.
Can I use 2-stroke oil in a four-stroke engine?
No. Four-stroke engines need crankcase oil of the viscosity and standard in their manual.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].
