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Oil & Fluids

AMSOIL vs Redline: Which Synthetic Oil Performs Better?

AMSOIL vs Redline
Last Updated on Aug 16, 2023 By Lillian Kazmierczak

Most oil brands perform very close to each other except for AMSOIL and Red Line because they are a league of their own in the full synthetic oil department.

That does not mean they are god-gifted, they are just above-average and will cost you a lot when compared to those from other brands.

As long as the oil you use meets your car specifications set by the manufacturer, the regular intervals and the maintenance you keep are more important than the brand you choose.

But we will still dig into the “AMSOIL vs Red Line’ debate so you get to know more about their offerings and differences.

AMSOIL – A quick overview

AMSOIL was founded in 1972 by Albert J. Amatuzio, a former jet fighter pilot. Headquartered in Superior, Wisconsin, they offer a wide range of synthetic lubricants, including motor oils, transmission fluids, gear oils, and greases.

AMSOIL’s synthetic motor oils are designed to provide superior protection and performance compared to traditional mineral-based oils. Formulated using high-quality synthetic base oils and advanced additive packages, they help reduce wear, protect against deposits, and improve fuel economy.

AMSOIL outperforms their competition with extended drain intervals and long-lasting performance.  They also offer a range of viscosity grades and specialized oils for specific applications, such as racing, diesel engines, and motorcycles.

Red Line – A quick overview

Founded in 1979 by Tim Kerrigan and based in Benicia, California, Red Line uses an advanced ester-based synthetic oil formulation that offers better wear protection and thermal stability than traditional synthetic oils.

Red Line also offers a range of viscosity grades and specialized oils for specific applications, such as racing, motorcycles, and marine engines. Their specialized oils are popular among enthusiasts and racers who demand the best performance from their vehicles.

AMSOIL vs Red Line

Features AMSOIL Red Line
Composition Traditional group IV synthetic oil More advanced ester-based synthetic oil
Types Transmission fluid, Gear lube, Coolant, Power Steering Fluid, Brake Fluid, Filters, Fuel additives, Cleaners Transmission fluid, Gear lube, Coolant, Power Steering Fluid, Brake Fluid, Filters, Fuel additives, Cleaners
Viscosity 0W20, 5W20, 5W30, 0W40, 5W50 0W20, 5W20, 5W30, 0W40, 5W50
Performance Above average More performance-oriented
Stability High Low
Durability Low High
Temperature resistance 235 F high and -20 F low 300 F high
Certification API, ILSAC, and OEM API, ILSAC, and OEM
  • Composition

Both AMSOIL and Red Line oils are full synthetic oils that use a combination of esters and other synthetic base oils. However, the specific blend of base oils and additives used by each brand can vary, leading to differences in their overall performance characteristics.

  • Types

Transmission fluid, gear lube, coolant, power steering fluid, brake fluid, filters, fuel additives, and cleaners are all available from both Red Line and AMSOIL.

  • Viscosity

Both oil brands have a high viscosity index, which means that their viscosity can be maintained even at high temperatures.

AMSOIL viscosity includes: 0W20, 5W20, 5W30, 0W40, and 5W50, whereas Red Line offers: 5W20, 5W30, 10W30, 0W40, 15W50, and 20W50.

  • Stability and durability

These brands designed engine oils to resist thermal breakdown and maintain engine performance and protection in high temperatures.

However, AMSOIL has high stability, which means it can withstand the formation of sludge and deposits in the engine under normal driving conditions. Red Line products, on the other hand, do well with high-power engines.

  • Temperature resistance

Red Line oils have a maximum temperature tolerance of 300 F, whereas those from AMSOIL can tolerate temperatures as low as -20 F. AMSOIL is fine for normal driving in hot or cold weather, but Red Line is better for rough driving in hot weather.

  • Certification

It’s worth noting that ISO viscosity grades are determined by the engine oil’s dynamic viscosity at 100°C, which is a measurement of its flow characteristics.

Different engine types require different viscosity grades of oil.

AMSOIL oil type ISO Red Line oil type ISO
0W20 20 5W20 20
5W20 26 5W30 30
5W30 48 10W30 32
0W40 40 0W40 40
5W50 68 15W50 50
20W50 50

AMSOIL Engine Oils Pros & Cons


  • Longer engine life: 75% more protection against wear and tear, which is higher than the industry standard
  • Cleaning: Better cleaning and protection from dirt and their signature series offers 5 times more cleaning than others
  • Lower maintenance: Their longevity makes them lower maintenance brand
  • Chemical combination: Their excellent chemical combination is 36% easier and faster for cold starts.
  • Certification: API, ILSAC, and OEM specifications


  • Lower maximum heat resistance: The maximum heat tolerance range is lower than that of Red Line

Red Line Engine Oils Pros & Cons


  • Synthetic formula: Famous ester formula that guarantees long-lasting protection of the engine
  • Friction reduction: Excellent friction reduction features on high-pressure engines
  • Cleaners: Red Line has high-quality system cleaners and water wetters
  • Certification: API, ILSAC, and OEM specifications


  • Minimum heat resistance: The minimum heat tolerance range is lower than AMSOIL
  • Frequent maintenance: Need frequent maintenance than AMSOIL

About the author

Lillian Kazmierczak

As far as I can remember, I would say I have been a car nut for my whole life. My father was a car dealer who used to change and repair his cars himself. This gave me the opportunity to get around all sorts of cars and get my hands dirty repairing vehicles from an early age.

A great fan of Japanese quality and German preciosity, my deep passion lies in older models that I believe have a flair that takes me back to my childhood! I also love their extraordinary durability and reliability when compared to today’s modern models.

When not out taking a ride, I enjoy socializing with fellow motorheads online and consuming any car facts and figures I can get my mind on!

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