What happens if you put diesel in your car that usually takes unleaded gasoline? Well, the answer is simple: nothing good. The same goes for your outdoor power equipment. You never want to operate your equipment with the wrong type of fuel. Using the right fuel type is critical for the longevity and efficiency of your STIHL power equipment.

STIHL equipment runs on a 50:1 mixture of gasoline and 2-cycle engine oil. Follow our guide below to learn how to properly mix oil and gas.

1. Make sure you refer to your manual before beginning any work on your STIHL equipment. Your manual will outline any specific concerns for your equipment’s fuel mixture.

2. Only use an approved gasoline container to avoid spillage, evaporation, and permeation.

3. Do you put the cheap stuff in your car? Well, even if you do, avoid downgrading your gasoline when purchasing for your outdoor power equipment. A minimum octane rating of 89 is recommended for the STIHL oil-gas mixture. If you opt for a higher octane rating, you may experience increased engine temperatures, in effect increasing the possibility of piston seizer and engine damage.

4. As mentioned above, gasoline-powered STIHL equipment operates on a 50:1 gas and oil mixture. Follow the chart below in making your mixture:

1 gallon of gasoline = 2.6 fluid ounces of oil
2.5 gallons = 6.4 fluid ounces
5 gallons = 12.8 fluid ounces

5. Shake it up! First pour the oil into your approved container, and then add the gasoline. Make sure your container is properly closed, then shake it to make sure the fluids mix together.

6. To make sure no dirt falls in and contaminates the mixture when fueling, clean the fuel cap and the surrounding area before you fuel up your equipment. Remove the fuel cap on your equipment slowly so any pressure build up releases slowly and don’t inhale any vapors.

7. STIHL recommends that you only mix as much fuel as you need for a few days’ worth of work. If you’re storing fuel, the storage period should never exceed three months. If you’re going to use fuel that’s been stored, make sure you return to step 5 and shake the fuel up before fueling your STIHL equipment.