posted 11-22-2006 02:25 PM ET (US)
There is NO need to use the "DFI" brown oil UNLESS you are operating in a very cold climate. It's formulation is to ensure proper flow and atomization without being mixed with gasoline before it gets to the bearings and cylinders, hence the COLD WEATHER required use only.
The Merc. PREMIUM PLUS (dark green) grade of oil has ALL the lubricity, cleaning properties, addative package, etc. you need to keep your Opti in top form. You can also usually get Premium Plus from the Barrel in "refill" form at outboard shops so there is a good cost savings as well.
Premium Plus IS certified for use in High-Performance Merc. Engines...DFI-Opti-Max Oil is NOT! That should tell the story on the lubricating properties.