10 Best Oil Additive For Older Engines of August 2025

List of Top Rated Oil Additive For Older Engines from thousands of customer reviews & feedback.

Updated On Aug 2025

1,226 Reviews Studied

By Customer Ratings

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Rislone 4405 Engine Oil Supplement Concentrate with Zinc Treatment - 11 oz. Read Review

  • Prevents camshaft wear
  • Reduces piston scuffing
  • Increases engine life
  • Makes newer oils work in older engines

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ZDDPPlus ZDDP Engine Oil Additive Zinc & Phosphorus 2 Bottles Read Review

  • PROTECT YOUR ENGINE - Older cars with flat tapped lifters-cam need the added zinc for protection
  • EASY TO USE - Simply empty entire 4oz contents of the bottle to a 4 to 6 quart oil change.
  • PREVENT METAL ON METAL CONTACT - ZDDPlus alters characteristics to prevent metal on metal contact
  • FOR USE ON PRE 1989 AND HIGH PERFORMANCE ENGINES
  • COMPATIBLE WITH SYNTHETIC AND CONVENTIONAL MOTOR OILS

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REV X ZDDP Oil Additive - Zinc & Phosphorus for Your Engine (2) Read Review

  • 1 Bottle Treats 6 qts. of oil - The most concentrated form of ZINC (ZDDP) Additive available. 3000-3200 parts per million when blended with 6 quarts of oil.
  • Provides Maximum Protection For Engine Break In.
  • Protects Flat Tappet Camshafts (Hydraulic or Solid).
  • Provides increased lubrication of Roller Lifter Bearings (Hydraulic or Solid).
  • Provides Maximum Metal To Metal Protection.

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ZDDPPlus ZDDP Engine Oil Additive Zinc & Phosphorus 5 Bottle Pkg Read Review

  • PROTECT YOUR ENGINE - Older cars with flat tapped lifters-cam need the added zinc for protection
  • EASY TO USE - Simply empty entire 4oz contents of the bottle to a 4 to 6 quart oil change.
  • PREVENT METAL ON METAL CONTACT - ZDDPlus alters characteristics to prevent metal on metal contact
  • FOR USE ON PRE 1989 AND HIGH PERFORMANCE ENGINES
  • COMPATIBLE WITH SYNTHETIC AND CONVENTIONAL MOTOR OILS

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LUCAS 10001 Heavy Duty Oil Stabilizer - 32 oz. Read Review

  • The product is 32oz hd oil stabilizer
  • Easy to use, increases power and miles per gallon
  • Made in USA, increase oil life at least 50 percent longer

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TriboTEX Nano Oil Additive Car Engine Treatment: Add to Engine Lube - Makes High Mileage Cars Like New with a Synthetic... Read Review

  • GROUNDBREAKING: Made in the USA – TriboTEX is a revolutionary engine oil additive. It contains synthetic nanoparticles developed with funding from the U.S. Department of Energy, NASA, & the National Science Foundation.
  • QUIETER & SMOOTHER PERFORMANCE: Reverses wear in bearings by building a diamond-like carbon coating.
  • UNIVERSAL: Compatible with all types of motor oil and can be used in gas or diesel engines. Use for both old and new cars. It is an excellent engine booster.
  • EFFICIENT: Our masterfully engineered engine treatment improves fuel consumption and reduces engine noise. It is time to improve your engine and take your driving experience to a new level.
  • GUARANTEED QUALITY: We know you will be delighted with this ground-breaking technology. Our treatment comes with a 100% satisfaction guarantee.

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Lucas Oil 10063 Engine Break in Oil Additive - TB Zinc Plus, 16 Ounce, Multi-Colored (LUC10063) Read Review

  • Affordable Solutions
  • Not designed for passenger car use
  • Exclusive blend of extreme pressure additives
  • Excellent for flat tappet camshafts or as an additive

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Hy-per Lube by Rislone ZDDP Supplement (4405-6PK) Read Review

  • Prevents camshaft wear
  • Reduces piston scuffing
  • Increases engine life
  • Makes newer oils work in older engines

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REV X ZDDP Oil Additive - Zinc & Phosphorus (1) Read Review

  • Treats 6 Quarts - The most concentrated form of ZINC (ZDDP) Additive available. 3000-3200 parts per million when blended with 6 quarts of oil.
  • Provides Maximum Protection For Engine Break In.
  • Protects Flat Tappet Camshafts (Hydraulic or Solid).
  • Provides increased lubrication of Roller Lifter Bearings (Hydraulic or Solid).
  • Provides Maximum Metal To Metal Protection.

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5 Quarts Lucas Oil 10631 SAE 30 High Zinc Engine Break-In Oils; Requires no moly supplement and no additional additives... Read Review

  • Quicker more efficient ring seal
  • Higher levels of zinc and phosphorus maximum protection
  • A must use for flat tappet camshaft break-in
  • Less blow-by equates more power and better ring seal
  • Requires no moly supplement and no additional additives