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

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* Size:


  • #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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Mark Cavanaugh uses Lucas Transmission Fix in 1995 Dodge 2500 Van

Before you spend big bucks rebuilding your transmission try Lucas, you won't believe my story. In July of 2003 I left Ohio pulling an 8000 pound trailer behind my 1995 Doge Van. I had just added a trans cooler. I had a transmission leak and lost a lot of fluid. I got off the highway and my transmission was slipping so bad, I disconnected the trailer and the van barely moved forward with the engine racing. I barely made it to an auto parts store and added some Lucas. The trans engaged and I went back to pick up my trailer. At first when I put it into gear it slipped but still moved forward, then it grabbed. Any sane person would have had the trans rebuilt, but instead we went for it. The weather was particularly hot, in the 90s in Ohio and over 100 degrees most of the way down. Several times, at least half a dozen, it got so hot the trans would slip and we had to stop. This transmission should have been toast! There is no way that van should have made it over 1500 miles to Texas, let alone pulling over 8000 lbs behind it! Well it's been a year and half and the transmission still slips in the morning for the first mile or so but I have been, and still drive it everyday. There is no telling how many thousands of transmission replacements and rebuilds could have been avoided if they had only tried Lucas first. Try it, it works!!

Mark Cavanaugh

Austin, Texas

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