posted 06-17-2004 05:25 PM ET (US)
Always better to be safe then sorry for sure.I always have to figure it out in my head like this:
50:1 equals
50 gallons of fuel to 1 gallon of oil
25 gallons of fuel to 1/2 gallon of oil or 2 quarts
12.5 gallons of fuel to 1 quart. This works out great for 12 gallon fuel tanks.
Now, given the above, the VRO uses less oil then pre-mix because it has a better ratio at cruise something like 60:1 roughly, and if everything is working correctly.
So, 1 pint does not seem enough for 18 gallons but, on the other hand, I never used the amount of oil I thought I should use, either on my 1985 70hp Evinrude with VRO, or my 1985 150hp Evinrude with VRO. I always look for smoke when the engine is idling and then at the end of the day I look at the Oil Tank to make sure it had used some oil. I know this is not a scientific method, but my engines are still running fine.
One thing I did do on my 1985 150hp Evinrude when I first bought it as the engine was used, was to purchase a brand new Oil Tank. I think I paid $25.00 for it on eBay. For my 1985 70hp Evinrude, the engine and everything else was new when I bought it.
Maybe someone else here as a few more scientific ideas.