Extreme Duty Marine Semi Synthetic 20W-50 Engine Oil

Extreme Duty Marine Engine Oil Semi Synthetic SAE 20W-50

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 severe 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


  • #10654 - 1 Quart (Case of 6) - 13 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
zinc Zinc Values

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Jamie Barnhard uses Lucas Transmission Fix in 83 Mercedes & Marine Transmissions

I have a 1983 Mercedes 300TD that shifted hard and had a front main seal leak. I was on a trip to Florida from Maryland and picked up a bottle at a truck stop in South Carolina. Not only did it shift better the main seal stopped leaking. Amazing Stuff. As a Marine Engine Mechanic, I started to using Transmission Fix in a lot of boat transmissions. Borg-Warner Velvet Drive, Borg Warner V-drive, Walters V-drive, Tonan and Twin-Disc. Transmission Fix works has worked wonders in them. Thanks for a great product. Jamie Barnhard / Barnhard Marine Services

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