Re: Using Synthetic oil in newer outboards ?
Be careful of independent oil companies that claim miracles by using their oils.<br /><br />All my Yamaha 4-stroke manuals specify an
API grade oil. These are oils that are certified by the American Petroleum Institution, and carry the "Starburst" symbol. You can go to API's website and find which oils are certified and licensed. Make sure to look for the specific viscosity and rating specification (Example: 10W-30 SE, SF, SG, SH, SJ).<br /><br />
http://eolcs.api.org/DisplayCompanyNames.asp <br /><br />Many oils, like Amsoil, claim their oils meets the API specification. But that is their
own claim, based on their
own testing results, as these oils are not certified by the API as such. You just have to take their word for it.

<br /><br />For example, Amsoil has specific oils designed for 4-stroke outboards. They claim these oils meet the API specification. But none of them are API certified. There are only a handfull of other Amsoil engine oils actually certified by the API, and some of them are
blended dino/synthetic oils, not 100% synthetic. None of them are specific outboard marine use oils.<br /><br />If engine failure could be attributed to the oil, then using a non-API certified oil
could void your warranty. BTW, there are brands of 100% synthetic oil (other than Amsoil) that
are API licensed.<br /><br />You really can't go wrong using the outboard manufacturer's brand oil. They will have synthetics too. It may cost a few dollars more, but you know it is specifically designed for your engine, and it ensures your warranty. Not to mention peace-of-mind.<br /><br />IMO, dino oils have everything in them that your outboard engine needs, and they have been proven to maintain engine wear for thousands of hours. I would begin using synthetics only after the first few changes of dino to ensure good ring seating and "wear in" of mating parts. <br /><br />I use both synthetic and dino in several different outboards. I haven't really noticed any major differences except that the synthetics cost more. Some of my outboards actually perform better and live longer on dino oils. And the oil still needs to be changed as frequent due to contamination.
