Thanks for the help. I need to see if Walmarts is 10-30 like I buy from the boat dealer. Last trip to boat dealer it cost $75 .00 for 6 qt oil & 2 filters. Being on penison It would be good to save a few dolllars. That way I can fish more. Retired.
You will never get a really knowledgeable answer to your question, which has been asked on many internet boat boards. Manufacturers never give out specific information on lubricants.
Merc says that you can use Premium Plus if the special opti oil isn't available. Premium Plus uses a semi-synthetic base oil that should reduce engine deposite formation. The original opti's said to use TCW3 oils before the special opti oil became available. But a lot of early (prior to about 2004) engines blew up early. To get even more confused, the racing and Sport versions of the Optimax say to use Premium Plus rather than the opti oil. : The opti oil is not TCW3 rated and it is not supposed to be mixed with oil.
My guess is that the opti oil was designed to combat deposit issues under normal operating conditions. Many people have successfully used nothing but TCW3 oil in their opti's without a problem. But the difference may be mean failure at 500 hr vs 2000 hr. Who knows? *I have not seen independent lab tests on DFI oils vs standard TCW3 oils.
I'd recommend using Merc Quickleen or Yamaha Ring Free (same stuff) at the specified dosage in your opti. Especially if you don't run Chevron or Texaco fuel, which already contains Techron. I'm pretty sure that both products are just Techron with a fuel stabilizer and rust inhibitor. They should help with deposit problems if you don't use the opti oil.
The Optimax is a very popular engine down here in Florida because of the lighter weight and 2-stroke performance characteristics, which work out well for high performance flats boats and bass boats. I looked to buy a Whaler that had an Optimax. They are more complex than a 4-stroke IMO.
I stopped by Wal-Mart today and saw that they have Quicksilver Premium Plus 2-Cycle TC-W3 O/B Oil for $25 a gallon. It says on the bottle that it is OK for DFI engines, but does not specifically say Optimax. Quicksilver also makes Quicksilver DFI 2-Cycle Outboard Oil which does say OK for Optimax on it. The DFI oil is not available at Wal-Mart and is much more expensive at West Marine. What do you think about running the Premium Plus in an Optimax engine? :-/