AMSOIL vs. Royal Purple: Picking the Best Engine Oil for Your Ride!

Two big names often come to mind regarding motor oil: Amsoil vs Royal Purple oil. Both brands produce high-quality, fully synthetic motor oils that aim to keep your engine running smoothly. However, some key differences between the two are worth considering.

Amsoil was founded in the USA in 1972 and emphasizes extended drain intervals of up to 25,000 miles. Royal Purple is a bit newer, founded in 1986 in Belgium, and recommends more frequent oil changes every 3,000-5,000 miles. Both exceed industry standards for wear protection, high-temperature performance, and low-temperature pumpability.

Amsoil stands out in its Signature Series line and undergoes an intensive proprietary formulation process. This results in exceptional protection against wear and oil consumption. However, it comes at a price – Amsoil costs more per quart than Royal Purple.

When choosing between these two industry leaders, you’ll want to consider your vehicle’s needs and maintenance schedule. Both deliver excellent lubrication, but Amsoil may be better suited for high-mileage vehicles and severe driving conditions.

Amsoil Motor Oil – Overview

Amsoil is a leading manufacturer of synthetic motor oils, lubricants and filters. Founded in 1972, Amsoil pioneered the development of synthetic motor oils made from natural gas as opposed to crude oil. Amsoil products are engineered to provide extended drain intervals, enhanced protection and performance for vehicles and equipment. The company’s signature line of synthetic motor oils undergo an intensive proprietary formulation process to achieve exceptional wear prevention and long engine life. Amsoil products are made in the USA and exceed industry and manufacturers specifications.

Main Features

  • Full synthetic formulation
  • Recommended 25,000 mile oil change interval for gasoline engines
  • Reduces friction and wear
  • Withstands high temperatures
  • Enhanced protection against rust and corrosion


  • Long lasting protection between oil changes
  • Improves fuel efficiency
  • Allows for extended drain intervals
  • Great cold weather performance
  • Protects high mileage engines


  • More expensive than conventional oils
  • Limited availability – mainly sold through dealers
  • Extended drain intervals not recommended for all vehicles

Royal Purple Motor Oil – Overview

Royal Purple is a premium synthetic oil brand that first launched in 1986. It is manufactured globally, including a production facility in Belgium. Royal Purple oils are formulated to enhance performance and provide exceptional engine protection. The synthetic base oils help to improve fuel efficiency and oil flow at start up in cold temperatures. Royal Purple uses proprietary additives to provide boosted wear protection, stabilize oil viscosity, and prevent corrosion. Their signature Synerlec additive improves compatibility with seals to reduce oil consumption.

Main Features

  • Full synthetic formulation
  • Enhanced with proprietary Synerlec additive
  • Protects against wear and oil breakdown
  • Improves oil flow in cold weather
  • Boosts fuel efficiency


  • Exceptional engine protection
  • Better cold temperature performance
  • Improves fuel economy
  • Less expensive when comparing Amsoil vs Royal Purple oil
  • Compatible with many seal materials
  • Low oil consumption


  • Limited availability in the US
  • Shorter change interval than other synthetics
  • Requires frequent oil changes

Amsoil Vs Royal Purple: Comparison

FeatureAmsoilRoyal Purple
Made in USAYesNo, made in Belgium
Full SyntheticYesYes
Recommended Drain Interval25,000 miles for gas engines 15,000 miles for diesel engines3,000-5,000 miles
API and ILSAC CertificationsYesYes
Signature Series costs (per quart)$9.15$7.75
Reduction in Oil ConsumptionExcellentVery Good
High Temperature ProtectionExcellentVery Good
Low Temperature PumpabilityExcellentVery Good
Reduces FrictionGoodExcellent
NOACK Test5.70 (10w30)11.20 (10w30)
Special Technology/AdditiveSuperSynSynerlec Technology

Must Check:

1. Cold and Hot Temps

Amsoil and Royal Purple use synthetic base oils. These oils have good pumpability in cold temperatures and remain stable in hot temperatures. Amsoil Signature Series oils undergo a specialized formulation process. This process enhances cold flow properties further.

This allows for easier starting. It also allows for faster lubrication at frigid temperatures. Amsoil resists oxidation at high temperatures. It surpasses the minimum industry standards. This provides enhanced protection against oil thickening.

Royal Purple exceeds industry standards for high-temperature protection. However, some independent tests suggest that Amsoil may have a slight edge in extreme conditions.

2. Performance and Efficiency

The advanced synthetic formulations of Amsoil vs Royal Purple deliver boosted engine performance. They also improve fuel efficiency compared to conventional oils.

Amsoil relies on its proprietary blend of base stocks and additives. This helps reduce friction, enabling smoother operation. It also enhances horsepower. The Synerlec additive in Royal Purple is designed to improve compatibility between the oil and seals. It helps reduce oil consumption.

Independent dyno tests on identical engines showed Amsoil delivered slightly better performance in terms of horsepower and torque gains. Both oils will provide significant gains in fuel economy over petroleum-based oils. However, long-term testing over 100,000 miles showed Amsoil maintained its fuel economy advantage better than Royal Purple.

3. Base oils and Additives Used

Both brands use high-quality base oils and unique additives. Amsoil uses premium synthetic base oils, enriched with additives for longevity and wear protection. Royal Purple incorporates proprietary Synerlec technology in its additives. This gives its oil superior film strength and corrosion protection.

The choice here depends on prioritizing long-term durability (Amsoil) or immediate engine protection (Royal Purple).

4. Certifications

Royal Purple oil vs Amsoil meets or exceed industry standards and certifications from API, ILSAC, ACEA, and major OEMs.

They are top-tier synthetic motor oils. They are designed to surpass the minimum requirements set by organizations like API and car manufacturers. The latest API SN Plus certification requires better sludge and deposit protection. It is 25% better than the previous API SN category.

Oils that just meet the API SN standard would not provide the same level of engine cleanliness as Amsoil or Royal Purple oils that are SN Plus certified. Both companies also reformulate their products to stay ahead of OEM changes and requirements.

Where Amsoil stands out is in documenting its testing and certifications. The company provides detailed reports on its certification testing, while Royal Purple does not disclose specifics.

5. Oil Change Intervals

The biggest difference between Amsoil vs Royal Purple is in their recommended oil change intervals. Amsoil Signature Series oils are designed for 25,000 mile drain intervals in gasoline engines. The company provides strong field-testing and analysis to support this extended interval.

In contrast, Royal Purple states its oils are suitable for 5,000 to 7,500 mile intervals in standard passenger vehicles. For turbocharged, supercharged, or high-performance engines, Royal Purple advises a 3,000 mile interval. The shorter interval is not due to any deficiencies in the oil itself. Rather, it acknowledges most engines are not ideally suited for extended changes without increased wear and deposits.

Amsoil accounts for this by making its 25,000 mile oil suitable only for engines in good operating condition and where regular oil analysis is performed. Amsoil offers other formulations for heavily used or modified engines better suited for 7,500 to 15,000 mile intervals.

Which Is the Better Engine Oil? Amsoil Vs Royal Purple

Amsoil Vs Royal Purple Review

When choosing engine oil, two big names often come up: Amsoil and Royal Purple. Both are well-respected, but which is better? Let’s break it down.

Amsoil is known for its long-lasting performance. It’s great for vehicles that go long periods between oil changes. Its synthetic formula helps in reducing engine wear and tear. This makes it a top choice for drivers who put a lot of miles on their vehicles.

On the other hand, Royal Purple is famous for its engine-cleansing properties. It’s designed to remove sludge and build-up from engines. This leads to better performance and efficiency. Royal Purple is a strong contender if you want to keep your engine running smoothly.

In terms of price, Amsoil is generally a bit more expensive. But, you get a product that lasts longer for those extra dollars. Royal Purple is more affordable, making it a good option for regular maintenance.

So, which is better? It depends on your needs. Amsoil is a great choice if you’re after longevity and can invest a bit more. Royal Purple is the way to go if you’re focused on engine cleanliness and a budget-friendly option. Both oils offer unique benefits, making them top picks in their own rights.

FAQs About AMSOIL vs. Royal Purple

Is Royal Purple just as good as AMSOIL?

Yes, Royal Purple is comparable to AMSOIL, but they excel in different areas. AMSOIL is well-known for its extended oil change intervals and superior performance in cold temperatures. Royal Purple stands out for two reasons. First, it has high-temperature stability. Second, it has engine-cleansing properties. The choice between the two depends on specific requirements. These requirements include driving conditions, engine type, and personal preferences.

Can I mix AMSOIL with Royal Purple?

Technically, you can mix AMSOIL with Royal Purple, as both are synthetic oils. However, it’s generally not recommended. Mixing different brands and formulations can dilute each oil’s unique benefits and performance characteristics. For the best results, it’s advisable to stick to one brand and type of oil for each oil change.

What’s so special about AMSOIL?

AMSOIL is special due to its pioneering role in synthetic motor oils and its commitment to quality and innovation. It offers exceptional protection against wear, superior performance in extreme temperatures, and extended oil change intervals. AMSOIL’s synthetic formulations are designed to reduce friction and wear, improving fuel efficiency and engine life. This makes it a popular choice for high-performance and long-lasting engine oil.

Do AMSOIL and Royal Purple offer warranty protection for my vehicle?

Both AMSOIL and Royal Purple got your back with limited warranty protection for their products, making sure they live up to specific performance standards. To keep that warranty coverage intact, just stick to the recommended service intervals and make sure you’re using the right product for your vehicle. It’s like giving your ride a VIP pass to longevity and top-notch performance.


Amsoil vs Royal Purple oil debate, it’s clear both have their strengths. Amsoil is ideal for those seeking long-lasting protection and fewer oil changes. It’s perfect for cold climates and high-performance needs.

Royal Purple, meanwhile, excels in high-temperature protection and engine cleanliness. It’s a great choice for regular maintenance and budget-conscious drivers. Ultimately, the best oil depends on your specific needs. Whether it’s climate, performance, or maintenance priorities, both Amsoil and Royal Purple offer reliable, high-quality solutions for your engine.

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