Extreme Duty Marine Semi Synthetic 20W-50 Engine Oil

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Extreme Duty Marine Semi Synthetic 20W-50 Engine Oil

Lucas Extreme Duty Marine Semi Synthetic 20W-50 Engine Oil is designed for use in high performance boats requiring the ultimate protection.

Lucas Extreme Duty Marine Semi Synthetic 20W-50 Engine Oil is manufactured with the highest quality paraffinic base oils and is fortified with an exclusive additive package containing high levels of Zinc, Moly and Phosphorus that provides a tougher, thicker additive film for maximum protection even under the most sever conditions. It lowers oil temperatures, extends oil life and minimizes metal fatigue.

Lucas Marine Semi Synthetic 20W-50 improves the film strength between the cylinder  wall and piston rings and slows oil burning while improving pressure levels in worn engines. It has good cold temperature properties and stands up to high operating temperatures. This product is compatible with methanol and all racing fuels.

Key Benefits

  • Excellent for use with supercharged, turbo charged or nitrous oxide high performance engines.
  • Protects against rust and moisture during long periods of storage.
  • Safely blends and is compatible with synthetic and non-synthetic oils.
  • Dropping point 540 lbs
  • Provides rust and corrosion protection in both fresh water and salt water environments.
  • Effective Water Resistance
  • Long Lasting
  • Resist Extreme Pressure
  • Extreme Friction Reducer


  • #10654 - 1 Quart (Case of 6) - 12 lbs
  • #10811 - 5 Quart (Case of 3) - 31 lbs
  • #10667 - 5 Gallon Pail (1 Pail) - 40 lbs
  • #10668 - 55 Gallon Drum (1 Drum) - 440 lbs


Product Spec Sheet Technical Data Sheet
Safety Data Sheet Safety Data Sheet

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Corey Homer uses Oil Stabilizer in modified 1965 Corvair Corsa

I added oil stabilizer (20% ratio as recommended) to my mildly modified 1965 Corvair Corsa. I had a technical question. It seems that all things set equal other than adding the stabilizer, my idle speed is faster than before. I am a degreed engineer, so I put on my problem solving hat. The best I could come up with is that the stabilizer has reduced the overall friction between components. Therefore, at the given idle air/fuel ratio the engine is able to spin freer. Is this possible? I have no problem stepping down the idle circuit a bit, but I guess I never expected to see that much difference. If that is the case, hats off to a great product. Plus, since the car is air cooled, head temps hover around 400F under normal operating conditions. I figured normal motor oil could use the added bonus of the stabilizer when continually operating at elevated temps.

Any hint regarding the idle question would be appreaciated.

Again, what phenominal product!

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