Many people know a 2-cycle engine runs on a mixture of oil and gasoline. What you might not know is how important it is that you use the right type of oil. The vast majority of our handheld chainsaws, blowers, edgers, trimmers, etc. run on 2-cycle engines, so this is a question that affects many lawn equipment owners. Two-cycle oils are chemically altered to combust or burn. They're very different than 4-cycle lubricants and cannot be used interchangeably. Also, keep in mind is that not all 2-cycle lubricants are created equally. Different oils meet different quality ratings and you need to use the right rating for your equipment. premixed-engine-oil-for-lawnmowers

Early Rating Systems

There are several different rating systems for 2-cycle oil. The National Marine Manufactures Association (NMMA) set the earliest standards governing 2-cycle lubricants. Currently, oils meeting their requirements carry the label TC-W3. This is typically the minimum oil rating required for use in small engines. The American Petroleum Institute (API) also developed a rating system. This system is rarely used today and the only classification still in use is TC. Most oils available today surpass this rating. You may see some oils described as API TC+.

Modern Oil Ratings

In 1994, the Japanese Automotive Standards Organization (JASO) developed a new standard oil rating that they revised in 2004 as JASO M345. This modern rating has three levels:
  • FB level oils meet strict requirements regarding lubricity, detergency, exhaust smoke, and exhaust system blocking.
  • FC levels oils have higher requirements for detergency, exhaust smoke, and exhaust system blocking.
  • FD oils meet the same requirements as FC but with a higher detergency requirement.
The International Standards Organization (ISO) also developed new standards during the mid-90s. Oils with these ratings meet a corresponding JASO level and on top of that they have to pass a 3 hour Honda test run.
  • ISO-L-EGB oils meet the same requirements as JASO FB and pass a test for piston cleanliness.
  • ISO-L-EGC oils meet the same requirements as JASO FC and pass a test for piston cleanliness.
  • ISO-L-EGD oils meet the same requirements as JASO FD and pass tests for piston cleanliness and detergent effect.

Which Oil Is For You?

The owner's manual that came with your lawn equipment tells you which type of oil to use. If you've misplaced your owner's manual, then you can typically find a copy on the manufacturer's website. Using the wrong oil rating can cause engine damage, so stick with what the manufacturer recommends. There's no need to use a higher oil rating than your owner's manual calls for. If you have any trouble figuring out which oil to use, you can ask us for help. Here at Richardson Saw & Lawnmower, we excel in delivering a quality service experience for all of our customers and we're happy to answer questions like this. And if you'd rather not mix the oil and gasoline yourself, many equipment manufacturers offer pre-mixed fuels specially designed for their engines. These include STIHL MotoMix and Echo Power Blend premixed fuels.