How Much Oil Should You Mix With Gas For Small Engine Tools?

Are you unsure about the correct ratio of oil to gas for your outdoor equipment? It can be confusing, especially if you're not familiar with the process. Using the wrong ratio can damage your tools and affect performance (and conversely, if you use a gas/oil mix in a tool that only needs pure gasoline, you're in trouble, too).

Products like string trimmers, gas pole saws, chain saws, and leaf blowers are common tools that run off a 2-stroke engine. All two-stroke (or 2-cycle) engines require the operator to add a mixture of fuel and oil to the fuel tank to support engine lubrication during operation and the engine combustion chamber.

If you're not sure what ratio your tool needs, start by checking your owner's manual. It'll list the recommended oil-to-gas ratio. The oil-to-gas ratio depends on the specific model and engine type. Two common ratios are 50:1 and 40:1.

Here's what that means:

• 50:1 Ratio: This means 50 parts of gasoline to 1 part of oil. For example, if you have 1 gallon of gasoline, you would add 2.56 fluid ounces of oil.
• 40:1 Ratio: This means 40 parts of gasoline to 1 part of oil. Using the same example, if you have 1 gallon of gasoline, you would add 3.2 fluid ounces of oil.

When mixing the oil and gas, ensure proper measurement and mix them thoroughly before filling the fuel tank. Using the correct ratio is important for the engine's performance, longevity, and overall functionality.

What’s the Easiest Way to Mix Gas and Oil?

Mixing gas and oil for a two-stroke engine can be done easily with the right tools and approach.

You'll need:

• Clean Fuel Container
• High-Quality 2-Stroke Oil (And, yes, quality matters)
• Gasoline
• Funnel
• Measuring cup

Step 1. Read the User Manual

• Refer to your user manual for the manufacturer's recommended unleaded fuel oil ratio. Is it 50:1? 40:1? Something different? Pay attention.

Step 2: Measure the Gasoline/Two-Stroke Fuel

• Pour the desired amount of fresh gasoline into the clean fuel container. The amount will depend on the recommended oil-to-gas ratio for your specific engine.
• Pro tip: If you're creating a mixture of gasoline for each ratio, use two fuel containers and label them both clearly on the outside of the container so there's never a mixup.
• One more pro tip for good measure: Prevent contaminated fuel. Only use clean containers, funnels, and measuring tools. Even small amounts of water or debris can affect engine performance.

Step 3: Add 2-Stroke Oil

• Measure the correct amount of high-quality two-stroke oil using a graduated measuring cup. Slowly pour the oil into the gasoline container.

Step 4: Mix Thoroughly

• Seal the airtight container and shake it to mix the oil and gasoline. Agitating the fuel mix helps create a homogeneous mixture.

Step 5: Let It Sit

• Allow the mixture to sit for a few minutes to ensure the oil and gasoline are well-blended.

Step 6: Use the Mixture Promptly

• Use the mixed gas and oil promptly to prevent any separation or settling. Stale fuel can lead to engine issues.

Step 7. Store Unused Mixture Properly

• If you have excess mixed fuel, store it in a cool, dry place in a sealed and labeled container. Again, it doesn't hurt to keep a container of premixed two-stroke fuel in your outdoor storage area if it's for a tool you'll use throughout the season. Be sure to check with the manufacturer's recommendations for storage duration.