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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Walter B. uses Lucas Heavy Duty Oil Stabilizer in 1991 240sx

I bought a 1991 240sx last September 2004 because I was going to modify it for the street. The car was in good condition. Had over 150,000 miles on the original engine, but ran like a top. The car had a noticeable smoke problem and a good acquaintance of mine told me to get Lucas Heavy Duty Oil Stabilizer. It, without a doubt, was the best advice I have ever listened to. I changed the oil and added just one quart and WOW. The engine seems to have a new lease on life. The smoking is gone completely and the engine seems to perform better. I use the Lucas oil treatment every time I change my oil without fail. I also use it in my wifes 2000 Impreza RS. Not because she has a problem, but because I like it so much I figure it can only help. At work I have become the Lucas unofficial spokes person. I tell people whom I work with to buy your product. After they try it they thank me. This product is simply amazing. I highly recommend it to anyone who wants the best for their engine new or old. Thank you Lucas. Walt B.

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