Mercury Opti info please.

[jwalker]

Originally Posted by willk

Does it have a sell by date?

Well, I've wondered about that but none of my saws seem to be complaining. An interesting thing has come to light re use of TCW3 in chainsaws. I've been using it since I first had an outboard motor, and I'm still using the same saws, however, later on the chainsaw manufactures started to stipulate that marine two stroke oil must not be used. I put this down to the high temperatures the air cooled equipment runs at, but since I'd had no bother I continued using it.

During researching the opti oils, the literature for the TCW3 Premium Plus (the implied lesser of the two oils) states that it is safe to use in air cooled equipment. It's the first time I've ever seen reference to that.

The other interesting thing about the Mercury oils is that the DFI oil is not recommended for the racing opti engines but the Premium Plus is. I smell a rat... Codders may have been on to something!

[Jeff]

I believe that the dfi oil incorporated additional detergent properties to reduce carbon build up associated with normal mixed running and trolling. By their nature, mercury racing applications run mostly at full tilt and presumably the tendency for carbon build up is minimised and guessing the extra lubriocity (so? ) in the premium is more importantx critical. They don't recommend using Optimal racing motors for general use I think
Of course, I could be completely wrong as often happens at my age 😊

[jwalker]

That's my take on it too. I think the Premium Plus is a better lubricant, it also contains additives which are now considered to be undesirable, namely, zddp and molybdenum, but they are known to protect if the oil film fails. Nevertheless, Mercury are still marketing it as a general purpose tcw3 lubricant. I see no reason that a good tcw3 isn't sufficient but it may produce a bit more carbon deposit under certain circumstances.

Thanks to all who have given info.