Two-Stroke Oil Ratings
Even today, there continues to be a huge number of questions regarding which oil is the one to use, which oil is better than another, and which oil is good enough. Let’s review the two-stroke lubricant standards; API TC; TCW; TC-W2; TC-W3; JASO FC; and ISO-L-EGD.
Two-stroke oils are usually given ratings from the API (American Petroleum Institute) “TC”, the BIA (Boating Industry Association) “TC-W” and currently the NMMA (National Marine Manufacturers Association) “TC-W2 and TC-W3”. The TC, TC-W and TCW2 standards are not current and do not meet the standards of today’s performance engines.
For a lubricant to receive one of these ratings it must pass certain levels of cleanliness and film strength. The lubricant is run at ratios up to 150:1 for specified times and loads. The engine is then examined for carbon deposits and for bearing and cylinder wear. If it meets the test criteria, the lubricant passes.
The Japanese Automobile Manufacturers Organization (JASO) developed a series of tests aimed at presenting more real-world conditions that a lubricant used in a motorcycle, snowmobile, ATV or PWC would encounter in use by consumers. They test for exhaust valve cleanliness, lubricity, exhaust smoke/blocking and initial torque. The highest JASO standard is FC & FD. These tests are very difficult to pass and are a better indicator of a lubricants level of protection and performance that TC-W3 in non-marine applications.
European engine manufacturers tested TC-W3 and JASO lubricants and determined that their engines needed a cleaner lubricant and one that would withstand higher heat conditions. They established the ISO international standards for two stroke engine lubricants. Their first standard, ISO-L-EGB was comparable to the JASO FB standard. They later developed the ISO-L-EGC which is similar to the JASO FC rating.
They felt they needed an even tougher standard for the newest generation of performance two stroke engines. The ISO-L-EGD was created to establish a higher standard of detergency and ability to withstand higher levels of heat. The new test runs for 3 hours vs 1 hour for the previous test.
If a lubricant is certified ISO-L-EGD it has passed the most stringent tests set by American, Japanese and European engine manufacturers. Polaris recommends TC-W3 lubricants, Yamaha JASO FC and Ski-Doo/Sea-Doo requires ISO-L-EGD lubricants.