About this item

• Product Overview

  Lubricates Top-End Components
  The intense heat of combustion and limitations of the oil-control piston ring result in a lack of oil at the top of each cylinder. AMSOIL Upper Cylinder Lubricant's unique additives provide that missing lubrication to fight piston-ring and cylinder wear, maximizing engine compression and horsepower. Its lubricity improvers also aid in protecting fuel injectors and other fuel-system components from wear, helping ensure excellent performance and long-life. AMSOIL Upper Cylinder Lubricant delivers 18 percent more lubricity than Lucas* and 20 percent more than Sea Foam* for better retention of horsepower and fuel economy (see chart below).¹

  Inhibits Corrosion
  Upper Cylinder Lubricant uses potent corrosion inhibitors to coat metal surfaces, block out moisture and stop deterioration before it starts. This is particularly important when using gasoline that contains ethanol due to its propensity to attract water and hasten corrosion. Inhibiting corrosion maximizes component life and reduces wear in the engine's top-end to guard against compression loss and maintain optimum power.

  • Lubricates fuel system and upper cylinders
  • Fights ethanol-related corrosion
  • Helps keep injectors clean
  • Compatible with capless fuel systems

  Keeps Injectors Clean
  Upper Cylinder Lubricant contains detergent additives designed to maintain injector cleanliness. While AMSOIL P.i. Performance Improver is designed to attack and remove stubborn injector deposits that can reduce power and fuel economy, Upper Cylinder Lubricant helps preserve injector and combustion-chamber cleanliness. Using it with every tank of fuel helps retain fuel-economy and performance gains and maximizes component life.

  Capless-Compatible Packaging
  Many new vehicles have replaced traditional fuel caps with capless systems. The threads on most bottles restrict them from opening the flap inside the fuel neck and make removing the bottle difficult. The AMSOIL Upper Cylinder Lubricant bottle is fully compatible with capless fuel systems. It's easy to insert, pour and remove the bottle.

  RECOMMENDATIONS

  • For use with cars and trucks.
  • For best results, use with every tank of fuel. Do not refill tank until almost empty.
  • Treats up to 25 gallons. Add entire bottle to tank at fill-up.
  • Treat large gas tanks with two bottles of Upper Cylinder Lubricant. Using more than two bottles is not recommended.
  • Safe for use with catalytic converters, oxygenated gas and E85 fuel.
  • Do not use with two-stroke or diesel engines.

  AMSOIL PRODUCT WARRANTY
  AMSOIL products are backed by a Limited Liability Warranty. For complete information visit www.amsoil.com/warranty/.

  HEALTH & SAFETY
  This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Safety Data Sheet (SDS). An SDS is available at www.amsoil.com or upon request at (715) 392-7101. Keep Out of Reach of Children.

   

   

  ¹ Based on independent testing of AMSOIL Upper Cylinder Lubricant, Lucas Upper Cylinder Lubricant and Sea Foam Motor Treatment obtained on 02/13/2019 using the ASTM D6079 modified for use with gasoline. *All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.

   

   

• Technical Specifications
  Data Bulletin

  Data Bulletins

  Warranty

  WARRANTY

  SDS

  SDS

  
  
  
• Product Reviews
  4.8 star rating

  Based on 374 reviews

  Based on 374 reviews

  See all customer reviews

  Sort by

  Most Recent Most Helpful Highest Rating Lowest Rating Oldest

  • 5 star rating
    Fuel Lubricate
    By  ROBIN,  a  Verified Buyer  from  Yorkton Sk.  on  May 11, 2026

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    I Run Premium fuel in my 2022 RAM 1500 the upper cylinder lubricate you are supposed to use it in every tank. I do believe that it works as it should use it every second tank fill. The long neck really helps with the capless fuel cap. I would recommend this.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Best additive
    By  RICARDO,  a  Verified Buyer  from  Ottawa  on  April 28, 2026

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    I use it once a month to give my engine extra protection. I have 150,000 km on it and my engine stays as quiet as a brand new car.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Amazing product, it works,
    By  CHARLES,  a  Verified Buyer  from  spruce grove , alberta  on  April 27, 2026

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    run this every second fill up engine runs amazing , smooth, and better fuel economy
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Buy Now
    By  98 Firebird,  a  Verified Buyer  from  DC  on  April 25, 2026

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    I purchased three products from AMSOIL, The Upper Cylinder Lubricant Corrosion Inhibitor, The DOMINATOR® Octane Boost, and The P.i.® Performance Improver Gasoline Additive I added all three to a full tank but, prior to doing this, I had filled the tank with Top Tier Fuel for this test Shortly after I took a ride, at first, I noticed nothing, but the very next day I put twenty miles on her, and that is when I noticed she ran quieter, and that the pick-up was back I highly recommend this product for older vehicles, and I want you to know, that these products are not a gimmick Check it out for yourself
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Better Gas Mileage
    By  GARY,  a  Verified Buyer  from  South Carolina  on  March 30, 2026

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    Increase MPG when added. I usually add in once per month, but it seems to have a positive effect on MPG for at least 2 or 3 tanks. I put in all 3 of my vehicles.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (1) NO (0)
  • 5 star rating
    Idle
    By  LAWRENCE,  a  Verified Buyer  from  Camry  on  March 20, 2026

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    Helped with idle along with PI additive
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  • 5 star rating
    Awesome product
    By  DOUG,  a  Verified Buyer  on  March 07, 2026

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    Keeps my vehicle running great
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Cheap Insurance
    By  CHRISTOPHER,  a  Verified Buyer  from  Florida  on  March 04, 2026

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    If you do a little research into Cafe standards and what is missing in fuel you will want to use this. Not all fuel has the amount of needed additives for today's direct injection engines, you want to keep those injectors clean and the rest of the upper cylinder too. I have a 2.4 cylinder turbo boxer engine 2025 Subaru, it really needs this. In practice terms I see a bit more pep in my step with this but not as much as with Amsoil P.I. I think every task is too much but every other tank should be just fine as I only allow a tank to go to 1/4 full and then refill. The bottle handles more than my tank holds so should be good to go.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Best Bang for your buck.
    By  JOEY,  a  Verified Buyer  from  Winnipeg  on  March 02, 2026

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    Helps quiet the noisy GM lifters. Helps smooth out the ride. Just as good as the in-store 30 buck cleaners.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    You have to try it
    By  Doc,  a  Verified Buyer  from  Brighton, MI  on  March 01, 2026

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    Describe the issue

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    This product is added at every fill up. I also use the AMSOIL P.i.® Performance Improver Gasoline Additive at the recommended intervals. After a short time you will notice a huge improvement in performance! If your engine uses direct fuel injection, which can cause a Carbon buildup, you have to try it!
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)

• Highlights

  Preserves Horsepower and Performance

  • Lubricates fuel system and upper cylinders.
  • Fights ethanol-related corrosion.
  • Helps keep injectors clean.
  • Compatible with capless fuel systems.
• Returns

  We offer easy returns for customers. If your product is unused and unopened, you may return it within 30 days for a full refund of the purchase price. View full AMSOIL Return Policy.

• Payments

  We accept Visa, Mastercard, American Express, Discover and PayPal, and provide secure checkout and encrypted payment processing.

• Product Overview

  Lubricates Top-End Components
  The intense heat of combustion and limitations of the oil-control piston ring result in a lack of oil at the top of each cylinder. AMSOIL Upper Cylinder Lubricant's unique additives provide that missing lubrication to fight piston-ring and cylinder wear, maximizing engine compression and horsepower. Its lubricity improvers also aid in protecting fuel injectors and other fuel-system components from wear, helping ensure excellent performance and long-life. AMSOIL Upper Cylinder Lubricant delivers 18 percent more lubricity than Lucas* and 20 percent more than Sea Foam* for better retention of horsepower and fuel economy (see chart below).¹

  Inhibits Corrosion
  Upper Cylinder Lubricant uses potent corrosion inhibitors to coat metal surfaces, block out moisture and stop deterioration before it starts. This is particularly important when using gasoline that contains ethanol due to its propensity to attract water and hasten corrosion. Inhibiting corrosion maximizes component life and reduces wear in the engine's top-end to guard against compression loss and maintain optimum power.

  • Lubricates fuel system and upper cylinders
  • Fights ethanol-related corrosion
  • Helps keep injectors clean
  • Compatible with capless fuel systems

  Keeps Injectors Clean
  Upper Cylinder Lubricant contains detergent additives designed to maintain injector cleanliness. While AMSOIL P.i. Performance Improver is designed to attack and remove stubborn injector deposits that can reduce power and fuel economy, Upper Cylinder Lubricant helps preserve injector and combustion-chamber cleanliness. Using it with every tank of fuel helps retain fuel-economy and performance gains and maximizes component life.

  Capless-Compatible Packaging
  Many new vehicles have replaced traditional fuel caps with capless systems. The threads on most bottles restrict them from opening the flap inside the fuel neck and make removing the bottle difficult. The AMSOIL Upper Cylinder Lubricant bottle is fully compatible with capless fuel systems. It's easy to insert, pour and remove the bottle.

  RECOMMENDATIONS

  • For use with cars and trucks.
  • For best results, use with every tank of fuel. Do not refill tank until almost empty.
  • Treats up to 25 gallons. Add entire bottle to tank at fill-up.
  • Treat large gas tanks with two bottles of Upper Cylinder Lubricant. Using more than two bottles is not recommended.
  • Safe for use with catalytic converters, oxygenated gas and E85 fuel.
  • Do not use with two-stroke or diesel engines.

  AMSOIL PRODUCT WARRANTY
  AMSOIL products are backed by a Limited Liability Warranty. For complete information visit www.amsoil.com/warranty/.

  HEALTH & SAFETY
  This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Safety Data Sheet (SDS). An SDS is available at www.amsoil.com or upon request at (715) 392-7101. Keep Out of Reach of Children.

   

   

  ¹ Based on independent testing of AMSOIL Upper Cylinder Lubricant, Lucas Upper Cylinder Lubricant and Sea Foam Motor Treatment obtained on 02/13/2019 using the ASTM D6079 modified for use with gasoline. *All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.

   

   

• Technical Specifications
  Data Bulletin

  Data Bulletins

  Warranty

  WARRANTY

  SDS

  SDS

  
  
  
• Product Reviews
  4.8 star rating

  Based on 374 reviews

  Based on 374 reviews

  See all customer reviews

  Sort by

  Most Recent Most Helpful Highest Rating Lowest Rating Oldest

  • 5 star rating
    Fuel Lubricate
    By  ROBIN,  a  Verified Buyer  from  Yorkton Sk.  on  May 11, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    I Run Premium fuel in my 2022 RAM 1500 the upper cylinder lubricate you are supposed to use it in every tank. I do believe that it works as it should use it every second tank fill. The long neck really helps with the capless fuel cap. I would recommend this.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Best additive
    By  RICARDO,  a  Verified Buyer  from  Ottawa  on  April 28, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    I use it once a month to give my engine extra protection. I have 150,000 km on it and my engine stays as quiet as a brand new car.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Amazing product, it works,
    By  CHARLES,  a  Verified Buyer  from  spruce grove , alberta  on  April 27, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    run this every second fill up engine runs amazing , smooth, and better fuel economy
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Buy Now
    By  98 Firebird,  a  Verified Buyer  from  DC  on  April 25, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    I purchased three products from AMSOIL, The Upper Cylinder Lubricant Corrosion Inhibitor, The DOMINATOR® Octane Boost, and The P.i.® Performance Improver Gasoline Additive I added all three to a full tank but, prior to doing this, I had filled the tank with Top Tier Fuel for this test Shortly after I took a ride, at first, I noticed nothing, but the very next day I put twenty miles on her, and that is when I noticed she ran quieter, and that the pick-up was back I highly recommend this product for older vehicles, and I want you to know, that these products are not a gimmick Check it out for yourself
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Better Gas Mileage
    By  GARY,  a  Verified Buyer  from  South Carolina  on  March 30, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    Increase MPG when added. I usually add in once per month, but it seems to have a positive effect on MPG for at least 2 or 3 tanks. I put in all 3 of my vehicles.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (1) NO (0)
  • 5 star rating
    Idle
    By  LAWRENCE,  a  Verified Buyer  from  Camry  on  March 20, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    Helped with idle along with PI additive
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Awesome product
    By  DOUG,  a  Verified Buyer  on  March 07, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    Keeps my vehicle running great
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Cheap Insurance
    By  CHRISTOPHER,  a  Verified Buyer  from  Florida  on  March 04, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    If you do a little research into Cafe standards and what is missing in fuel you will want to use this. Not all fuel has the amount of needed additives for today's direct injection engines, you want to keep those injectors clean and the rest of the upper cylinder too. I have a 2.4 cylinder turbo boxer engine 2025 Subaru, it really needs this. In practice terms I see a bit more pep in my step with this but not as much as with Amsoil P.I. I think every task is too much but every other tank should be just fine as I only allow a tank to go to 1/4 full and then refill. The bottle handles more than my tank holds so should be good to go.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Best Bang for your buck.
    By  JOEY,  a  Verified Buyer  from  Winnipeg  on  March 02, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    Helps quiet the noisy GM lifters. Helps smooth out the ride. Just as good as the in-store 30 buck cleaners.
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    You have to try it
    By  Doc,  a  Verified Buyer  from  Brighton, MI  on  March 01, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    This product is added at every fill up. I also use the AMSOIL P.i.® Performance Improver Gasoline Additive at the recommended intervals. After a short time you will notice a huge improvement in performance! If your engine uses direct fuel injection, which can cause a Carbon buildup, you have to try it!
    Bottom Line

    Yes, I would recommend this to a friend.
    Was this review helpful?

    YES (0) NO (0)