Amsoil Vs Royal Purple: Which is More Durable?

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Using the right motor oil for your car’s engine has a lot of advantages; you’d drive longer miles before an oil change, enjoy more fuel efficiency, and your car’s engine would last longer too. Amsoil and Royal Purple are among the best motor oil brands that produce some of the highest-quality oils for different auto engines.

This Amsoil vs Royal Purple comparison looks into the distinctiveness in the formula used by these top brands to produce high-quality oils of different grades/viscosities.

On a quick note, Royal Purple motor oils are more effective in friction reduction than any other motor oil, while Amsoil motor oils are remarkable for offering a longer duration between oil changes- up to 15,000 miles.

Overview of Amsoil Motor Oils

The brand, Amsoil, produces motor oils of different viscosities – 5w30, 5w20, 10w30, 0w20, 10w40, 5w50, 0w16, and 10w30. Amsoil is an American motor oil brand that has been around since 1969.

Amsoil uses naturally shear-resistant base oils with viscosity improvers in its oil formulas; this helps to make the oils withstand extreme heat and temperatures. Reports show that Amsoil’s synthetic oils’ viscosity breakdown is 46% better than Mobil 1 synthetic oils – but what about Royal Purple?

Overview of Royal Purple OIl

Royal Purple is also an American motor oil brand that produces motor engine oils of different grades/viscosities. The brand is popular for making motor oils that reduce friction and improve combustion efficiency more effectively than practically other oils in the market.

Also, Royal Purple synthetic oils increase engines horsepower and torque by 3 – 5% compared with other top oils from other brands.

Royal Purple motor oils are among the most affordable options in different offline and online stores. Below is comprehensive comparison between Royal Purple and Amsoil.

Amsoil Vs Royal Purple: Comparison

Oil Brand / FeatureAmsoil OilsRoyal Purple Oils
Maximum Recommended Oil Change IntervalUp to 15k milesUp to 10k miles
Wear Protection ExcellentExcellent
Reduces Friction GoodExcellent
Special Technology/AdditiveSuperSynSynerlec Technology. 
NOACK Test5.70 (10w30)11.20 (10w30)
Price ExpensiveAffordable

1. Cold and Hot Temps

Amsoil synthetic motor oils flow faster in cold temperatures; they seem lighter than Royal Purple oils, which makes them flow faster. So, if you live in an area with low temperatures, Amsoil synthetic oils would perform better for your engine than Royal Purple.

2. Performance and Efficiency

Both Royal Purple and Amsoil synthetic oils contain engine cleaning additives to keep the engine clean inside – removing sludge and carbon deposits that may affect the engine’s performance negatively. However, Amsoil synthetic oils perform better than Royal Purple oils even after several miles.

When subjected to the NOACK volatility test, it appeared that Amsoil has very low volatility compared with Royal Purple.

So, seeing Amsoil Signature Series is rated for 25,000 miles is just acceptable because the oil still flows pretty well even after severe torture. Here’s a video that shows how Amsoil performs over Royal Purple.

3. Base oils and Additives Used

Royal Purple is made with premium base oils and a special additive called Synerlec to improve the viscosity of its oils. With the help of this technology, Royal Purple oils perform well in different temperatures – both cold and hot climates.

In contrast, Amsoil says it used premium industry-leading base stocks with anti-wear additives and detergents in its synthetic formula. Actually, both Royal Purple and Amsoil synthetic oils are good in keeping an engine clean inside and protecting against wear.

4. Certifications

Both Amsoil and Royal Purple synthetic oils meet GM’s Dexos1 specification and other OEM specifications. Also, the oils meet the industry’s ILSAC, API, and SN+ specifications. They are really good for different types of auto engines – for the specified grades.

5. Oil Change Intervals

With Amsoil synthetic oils, you can drive up to 15,000 miles on a single oil change, but you can’t get such high mileage with Royal Purple.

The maximum recommended oil change interval for Royal Purple synthetic oils is 12,000 miles. So, if you need an oil that would you longer drain intervals, Amsoil is the choice here.


In this Royal Purple vs Amsoil comparison, there’s no definite winner; your pick depends on what you need for your engine. If you want an oil that gives you more time between drain intervals, you should go with Amsoil.

In contrast, if you need an oil that would improve your engine’s horsepower and torque, Royal Purple is the ideal choice. Both brands produce oils of different grades, so you can easily pick the grade specified for your engine.

More so, motor oils from Amsoil and Royal Purple meet all industry specifications for synthetic engine oils, and they are also recommended by different OEMs. However, Amsoil synthetic oils are slightly more expensive than Royal Purple oils. Well, the price difference won’t be a problem for someone that needs a longer OCI.

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