2 Stroke Mix Calculator

2-Stroke Engine Mix Calculator

Calculate the correct fuel-to-oil ratio for your 2-stroke engine. Using the wrong ratio can damage your engine.

Understanding 2-Stroke Engine Fuel Mix Ratios

Two-stroke engines are known for their simplicity, power-to-weight ratio, and ease of maintenance. Unlike four-stroke engines, which have separate lubrication systems, 2-stroke engines rely on a mixture of gasoline and specific 2-stroke oil to lubricate their internal components as the fuel/air mixture passes through the crankcase. Getting this ratio correct is crucial for the longevity and performance of your engine.

Why is the Fuel-to-Oil Ratio Important?

• Lubrication: The 2-stroke oil mixes with the gasoline and is drawn into the crankcase. As the mixture moves through the engine, it lubricates the crankshaft bearings, connecting rod, piston, and cylinder walls. Insufficient oil leads to increased friction, overheating, and premature wear or catastrophic engine failure.
• Cooling: The fuel itself also plays a role in cooling the engine. Too much oil can lean out the fuel mixture, leading to overheating.
• Emissions and Performance: An incorrect ratio can also affect combustion, leading to poor performance, excessive smoke, fouled spark plugs, and increased emissions.

Common 2-Stroke Oil Ratios

The most common ratios you'll encounter are:

• 50:1: This is a very popular ratio for many modern engines, especially those found in motorcycles, chainsaws, leaf blowers, and outboard motors. It means 1 part oil to 50 parts gasoline.
• 25:1: This ratio provides more oil per unit of fuel and is often recommended for older engines, engines that are run very hard or under heavy load, or if you are using a less advanced mineral-based oil.
• Other Ratios: You might occasionally see ratios like 40:1, 32:1, or even 20:1, depending on the specific engine manufacturer and application. Always consult your engine's manual for the recommended ratio.

How to Use This Calculator

This calculator simplifies the process of determining how much oil to add to your gasoline. Simply:

1. Enter the total amount of gasoline you are preparing in liters.
2. Input the recommended oil ratio for your engine in the format 'X:1' (e.g., 50:1, 25:1).
3. Click "Calculate Mix".

The calculator will then tell you the precise amount of 2-stroke oil (in milliliters) you need to add to achieve the correct mixture.

Example Calculation

Let's say you have a 10-liter fuel can and your equipment requires a 40:1 fuel-to-oil ratio.

• Fuel Amount: 10 Liters
• Oil Ratio: 40:1

To calculate the oil needed: 1 Liter = 1000 milliliters 10 Liters = 10 * 1000 = 10000 ml of gasoline. For a 40:1 ratio, you need 1 ml of oil for every 40 ml of gasoline. Total oil needed = (Total fuel in ml) / (Ratio denominator) Total oil needed = 10000 ml / 40 = 250 ml of 2-stroke oil.

This calculator will perform this calculation for you automatically.