About this item

• Product Overview

  Specially engineered and formulated for maximum horsepower and protection without the shortcomings of using automotive, PAG or mineral-based karting oils in a high-revving, air-cooled, splash-lubed environment. Resists rust, corrosion and foaming. Safe for use in gasoline and alcohol-burning stock or modified engines.

  See the product data sheet for full details.

  MAXIMIZES HORSEPOWER

  • Engineered with specialized friction modifiers and advanced additives that reduce energy loss due to friction.
  • Combines the horsepower of a lite oil with the wear protection of a heavier oil.
  • Helps racers put more power to the ground.

  HELPS REDUCE HEAT

  • Formulated with pure synthetic base oils that resist extreme heat common to air-cooled racing engines better than conventional oils.
  • Increased thermal stability helps reduce operating temperatures and guards against sludge and deposits that rob engines of power, promoting optimum engine performance and life.

  FIGHTS ENGINE WEAR

  • Engineered with powerful anti-foam agents to resist foam common to high-rpm operation.
  • Forms a durable lubricating film between engine parts to protect in the most extreme conditions.
  • Helps reduce piston-ring, cylinder and valve wear for maximum engine compression and power.

  See the product data sheet for full details.

• Technical Specifications
  Data Bulletin

  Data Bulletins

  SDS

  SDS

  
  
  
• Product Reviews
  5 star rating

  Based on 42 reviews

  Based on 42 reviews

  See all customer reviews

  Sort by

  Most Recent Most Helpful Highest Rating Lowest Rating Oldest

  • 5 star rating
    Most power
    By  MATT,  a  Verified Buyer  on  May 22, 2026

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    Most power we see on dyno with Flat kart motors period. we break in every motor with the break in oil as well
    Bottom Line

    Yes, I would recommend this to a friend.
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  • 5 star rating
    Just what the engine ordered
    By  DANA,  a  Verified Buyer  from  Kelowna  on  January 12, 2026

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    As the BC Briggs racing dealer, ( and this is what is recommended by Briggs themselves ) I sell this to all my customers along with the Amsoil Break-in Oil. To date I have had no negative issues with these products.
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  • 5 star rating
    Briggs 4T
    By  SCOTT,  a  Verified Buyer  from  San Diego   on  August 26, 2025

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    This stuff works amazing, one of the best product I've ever used in our Briggs and Stratton W/F engine.
    Bottom Line

    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent works great
    By  KENNETH,  a  Verified Buyer  from  Alden NY  on  May 12, 2025

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    Motor runs great no problems what so every
    Bottom Line

    Yes, I would recommend this to a friend.
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  • 5 star rating
    Kart racing
    By  Pickle,  a  Verified Buyer  from  West Virginia   on  March 22, 2025

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    I have used the Briggs 4T in every air cooled racing engine that we use. Have used other oils but the 4T by far hands down the best. I will continue to use until proven wrong. Love this stuff.
    Bottom Line

    Yes, I would recommend this to a friend.
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    YES (0) NO (0)
  • 5 star rating
    Amsiol 4T racing oil
    By  AARON,  a  Verified Buyer  from  Canada   on  July 02, 2024

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    I’ve used this oil for my racing engine’s and love the protection it provides against wear and tear. Highly recommended Amsoil for you racing engine! 👍
    Bottom Line

    Yes, I would recommend this to a friend.
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    YES (0) NO (0)
  • 5 star rating
    works great
    By  ERNEST,  a  Verified Buyer  on  July 02, 2024

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    Terrible aftertaste but it gets the job done
    Bottom Line

    Yes, I would recommend this to a friend.
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    YES (1) NO (1)
  • 5 star rating
    4 stroke karting oil
    By  JORDAN,  a  Verified Buyer  from  Miami, Fl  on  February 14, 2024

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    Best 4 stroke racing oil on the market.
    Bottom Line

    Yes, I would recommend this to a friend.
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  • 5 star rating
    Need 4 Speed Karting
    By  JERRY,  a  Verified Buyer  from  El Paso   on  February 07, 2024

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    Perfect product for Briggs racing engines.
    Bottom Line

    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great product
    By  MIKE,  a  Verified Buyer  from  Ontario, Canada  on  August 27, 2023

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    Been using this oil in our race engines the past 5 years with no issues, great product.
    Bottom Line

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

    YES (1) NO (0)

• Highlights

  • Tested and validated by Briggs & Stratton and AMSOIL
  • Combines the protection of a heavier oil with the performance of a lite oil
  • Reduces harmful heat
  • Inhibits foam
  • Resists corrosion
• 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

  Specially engineered and formulated for maximum horsepower and protection without the shortcomings of using automotive, PAG or mineral-based karting oils in a high-revving, air-cooled, splash-lubed environment. Resists rust, corrosion and foaming. Safe for use in gasoline and alcohol-burning stock or modified engines.

  See the product data sheet for full details.

  MAXIMIZES HORSEPOWER

  • Engineered with specialized friction modifiers and advanced additives that reduce energy loss due to friction.
  • Combines the horsepower of a lite oil with the wear protection of a heavier oil.
  • Helps racers put more power to the ground.

  HELPS REDUCE HEAT

  • Formulated with pure synthetic base oils that resist extreme heat common to air-cooled racing engines better than conventional oils.
  • Increased thermal stability helps reduce operating temperatures and guards against sludge and deposits that rob engines of power, promoting optimum engine performance and life.

  FIGHTS ENGINE WEAR

  • Engineered with powerful anti-foam agents to resist foam common to high-rpm operation.
  • Forms a durable lubricating film between engine parts to protect in the most extreme conditions.
  • Helps reduce piston-ring, cylinder and valve wear for maximum engine compression and power.

  See the product data sheet for full details.

• Technical Specifications
  Data Bulletin

  Data Bulletins

  SDS

  SDS

  
  
  
• Product Reviews
  5 star rating

  Based on 42 reviews

  Based on 42 reviews

  See all customer reviews

  Sort by

  Most Recent Most Helpful Highest Rating Lowest Rating Oldest

  • 5 star rating
    Most power
    By  MATT,  a  Verified Buyer  on  May 22, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    Most power we see on dyno with Flat kart motors period. we break in every motor with the break in oil as well
    Bottom Line

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

    YES (0) NO (0)
  • 5 star rating
    Just what the engine ordered
    By  DANA,  a  Verified Buyer  from  Kelowna  on  January 12, 2026

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    As the BC Briggs racing dealer, ( and this is what is recommended by Briggs themselves ) I sell this to all my customers along with the Amsoil Break-in Oil. To date I have had no negative issues with these products.
    Was this review helpful?

    YES (0) NO (0)
  • 5 star rating
    Briggs 4T
    By  SCOTT,  a  Verified Buyer  from  San Diego   on  August 26, 2025

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    This stuff works amazing, one of the best product I've ever used in our Briggs and Stratton W/F engine.
    Bottom Line

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

    YES (0) NO (0)
  • 5 star rating
    Excellent works great
    By  KENNETH,  a  Verified Buyer  from  Alden NY  on  May 12, 2025

    Open report issue form

    Describe the issue

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    Motor runs great no problems what so every
    Bottom Line

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

    YES (0) NO (0)
  • 5 star rating
    Kart racing
    By  Pickle,  a  Verified Buyer  from  West Virginia   on  March 22, 2025

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    I have used the Briggs 4T in every air cooled racing engine that we use. Have used other oils but the 4T by far hands down the best. I will continue to use until proven wrong. Love this stuff.
    Bottom Line

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

    YES (0) NO (0)
  • 5 star rating
    Amsiol 4T racing oil
    By  AARON,  a  Verified Buyer  from  Canada   on  July 02, 2024

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    Describe the issue

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    I’ve used this oil for my racing engine’s and love the protection it provides against wear and tear. Highly recommended Amsoil for you racing engine! 👍
    Bottom Line

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

    YES (0) NO (0)
  • 5 star rating
    works great
    By  ERNEST,  a  Verified Buyer  on  July 02, 2024

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    Terrible aftertaste but it gets the job done
    Bottom Line

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

    YES (1) NO (1)
  • 5 star rating
    4 stroke karting oil
    By  JORDAN,  a  Verified Buyer  from  Miami, Fl  on  February 14, 2024

    Open report issue form

    Describe the issue

    Failed to verify captcha

    Cancel Submit
    Best 4 stroke racing oil on the market.
    Bottom Line

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

    YES (1) NO (0)
  • 5 star rating
    Need 4 Speed Karting
    By  JERRY,  a  Verified Buyer  from  El Paso   on  February 07, 2024

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    Describe the issue

    Failed to verify captcha

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    Perfect product for Briggs racing engines.
    Bottom Line

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

    YES (1) NO (0)
  • 5 star rating
    Great product
    By  MIKE,  a  Verified Buyer  from  Ontario, Canada  on  August 27, 2023

    Open report issue form

    Describe the issue

    Failed to verify captcha

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    Been using this oil in our race engines the past 5 years with no issues, great product.
    Bottom Line

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

    YES (1) NO (0)