Mobil 1 Vs Royal Purple Vs AMSOIL

All the three motor oils – Mobil 1, Royal Purple and AMSOIL are synthetic oils by major companies which are continuously competing to control the key market share in the synthetic motor oil market.

While all three are premium motor oils that ensure high engine performance and under general circumstances, it is ideal to change it at least once a year, the main difference lies in their formulations. Each has its own selling points, but who wins on a head to head showdown for the best synthetic motor oil?

For instance, comparing the life of the oil, AMSOIL oil provides around 25,000 miles before being drained while Mobil 1 and Royal Purple provide a durability of 15,000 miles and 12,000 miles respectively. However, as compared to the other oils, AMSOIL is also the most expensive one. Thus, each engine oil brand has its own pros and cons.

So, in this article, we will try to figure out the high performance engine oil that best suits your needs by comparing them in different parameters such as pricing, viscosity, etc. There are some parameters in which each engine oil performed differently and others where they performed similarly.

So, let’s start with a table comparing the different types of premium synthetic oils –

BrandAMSOILRoyal PurpleMobil 1
Suitable EnginesAll TypesAll TypesHigh Performance Engines
Suitable EnginesGasolineGasolineGasoline and Diesel
Fuel EconomyMaximumModerateLeast
Value for MoneyExpensiveCheapestModerate
Grades Available 0W-20 – 5W-50 (7 Variants)0W-20 – 10W-30 (4 Variants)5W-20 – 20W-50 (5 Variants)


Differences between Mobil 1, Royal Purple and AMSOIL are –

Fuel Economy

Good synthetic oils reduce the friction of the engine parts effectively. This in turn helps reduce oil consumption and help make the car more fuel efficient. To check these three oil favourites, we put them through the standardized TEOST 33C deposit control test, which tests the deposit fighting power of the engine oil.

These deposits can cause severe damage to the engine as well as the fuel economy of the car in the long wrong. Generating just 7 mg of deposits, AMSOIL performs outstandingly with 3-4 times the deposit fighting power as compared Royal Purple (25.4 mg) and Mobil 1 (28.2 mg).

Considering that the API SN and ILSAC GF-5 motor oil industry standards dictate a TEOST 33C limit of 30 mg, both Mobil 1 as well as Royal Purple barely pass the standards.

In the practical world too, AMSOIL leads the way with an average improvement of 6.54% boost in fuel economy. It is followed by Royal Purple with an economy boost of 4.5% and Mobil 1 comes last with an improvement of just 2% in the fuel economy.


The advantage of full synthetic oils is that it lasts for a longer than non-synthetic oils and generally requires being changed annually.

AMSOIL provides a durable mileage of around 25000 miles per refill, which is almost than double of the mileage provided by Mobil 1 at 15000 miles and Royal Purple at 12000 miles. This feature regulates the amount of oil changes that you need and helps you save some money depending on your personal requirement.

Value for Money

Price is one of the most important factors in buying the right engine oil, considering the fact that engine oils require to be changed in regular intervals. They are priced accordingly –

BrandViscosityPrice per quart*
AMSOIL Signature Series Synthetic5W-30Slightly Expensive
Royal Purple High Performance Synthetic5W-30Affordable
Mobil 1 Extended Performance5W-30Affordable

* All the prices mentioned are the as when we are publishing this article.

We can see that AMSOIL is clearly the most expensive oil of the three, while Royal Purple is the most economically priced.

Given below is a comparison table of the performance of the 5W-30 variant of the three brands respectively –

Test TypeAMSOIL (5W-30)Mobil 1 (5W-30)Royal Purple (5W-30)
Viscosity @ 100 ºC, cSt (ASTM D445)10.410.611.03
Viscosity, @ 40 ºC, cSt (ASTM D445)57.159.856.25
Viscosity Index173169193
Pour Point, ºC (ASTM D97)-50 (58)-40-48 (-54)
Flash Point, ºC (ASTM D92)220 (428)230216 (420)

*All values are as specified by the respective company and are based on standardised tests.


Similarities between Mobil 1, Royal Purple and AMSOIL are –


Viscosity Grade

Despite several claims of differences in the viscosity of these engine oils, the truth is that the viscosity of these engine oils is usually almost identical to the other.

Being premium brands, each product is usually of precise viscosity. However, what is important to understand is that each brand has own range of different grades of engine oil viscosity.

The most common engine oil grades include:

  • 0W-20
  • 0W-40
  • 5W-20
  • 5W-30
  • 5W-40
  • 10W-30
  • 10W-40
  • 15W-40
  • 20W-50

If the oil is of the wrong viscosity, it could lead to severe wear and tear as well as a drop in the engine mileage due to increased fuel consumption. So, it is very important to know the viscosity that best suits your engine. Generally, this information is specifically provided in the owner’s manual of the car.


Also Read:-

Which engine component stores oil for lubrication?



All the three are premium quality motor oils that carry the latest ILSAC (International Lubricants Standardization and Approval Committee) and API (American Petroleum Institute) engine oil licenses. Further, they have been granted GM Dexos 1, which is basically the standard specification for gasoline engine oils governed by GM. These are important benchmarks which ensure that the oils meet the minimum standards of production to ensure safe consumer usage and reliability.


Useful Questions:-

Royal Purple vs AMSOIL gear oil?

Both are very high grade, non-corrosive gear oils which help reduce friction and provide protection to heavily loaded gears. Royal Purple’s synthetic gear oil has the patented Synerlec Additive Technology which helps in reducing friction as well as unnecessary impurities.

However, when put through the Shear test, Royal Purple’s viscosity dropped drastically (40.6%) as compared to AMSOIL (3.9%). Since viscosity affects the friction reduction ability, a well-balanced formulation by AMSOIL helps it perform better and deliver a more long lasting lubrication than Royal Purple.


Royal Purple vs AMSOIL Oil Filter?

Good quality oil filters help ensure longevity of your vehicle by keeping the unnecessary contaminants from your fuel. A high quality filter helps keep your engine free from such unnecessary contamination. Royal Purple’s oil filter is an incredibly high quality one which provides particle removal with 99% filtration at 25 microns.

However, AMSOIL beats Royal Purple with an oil filter which provides particle removal with 99% filtration at 20 microns.

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Royal Purple vs AMSOIL Transmission Fluid?

Using transmission fluid can help in dramatically reducing heat generation and wear and tear of your transmission system.

The wrong choice of transmission fluid may lead to issues such as increased fuel consumption, wear and tear and also increase the chances of transmission failure. Royal Purple ATF helps in effectively lubricating the system and keeps it cool.

However, Royal Purple is best suited for gasoline engines and is not suggested for CVT and DVT application. AMSOIL ATF has designed to exceed the most stringent industry standards and to outperform most other transmission fluids in the market.

However, it too is not used for CVT or Ford Type F transmissions. Although AMSOIL beats Royal Purple in several standard test parameters, the price for it is the extra bucks that the AMSOIL user has to shell out.


Can I mix Mobil 1 with Royal Purple?

Yes, you can mix the two synthetic oils without facing any issues. However, be careful about choosing the same viscosity grade as it may lead to severe problems for your vehicle such as increased fuel consumption, wear and tear etc.


Mobil 1 vs Royal Purple Gear Oil?     

Both are supreme quality gear oils which help prevent the metal-to-metal contact that causes friction and wears gears down, and it removes heat from around gears. Mobil 1’s additive package includes sulfur and phosphorus, but does not corrode yellow metals like brass bearing cages.

Due to its outstanding shear stability, it extends drain intervals while reducing wear and tear. Royal Purple’s synthetic gear oil has the patented Synerlec Additive Technology which helps in reducing friction as well as unnecessary impurities while preventing harm to the soft metals in the system.


Mobil 1 vs Royal Purple 75w90?

Mobil 1 Synthetic Gear Lube LS 75W-90 is a top grade performance synthetic oil designed to help meet the highest level performance requirements of modern passenger vehicles in all types of operating conditions in order to reduce wear under the high speed, high torque and high horsepower conditions in competitive racing and high performance automobiles.

Royal Purple Max Gear 75W-90 is another high performance oil which successfully meets the GL-5 industry standards. While it is more expensive than its counterparts, it is also suitable for GL-4 applications like manual transmissions and front-wheel-drive transaxles.


Does Royal Purple Clean the Engine?

Yes, Royal Purple indeed cleans the engine with advanced synthetic solvency. Engine oils have the tendency to collect dust and dirt over time, forming a layer of sludge.

This sludge can lead to engine knocking, reduced engine power, poor fuel consumption and eventual damage if left unchecked. It dissolves the unnecessary contaminants and deposits of the engine and helps the engine function more freely, in turn increases the overall performance of the vehicle.


Product Reviews:-

1) Amsoil Signature Series 5W-30 Synthetic Motor Oil:- 

Amsoil Signature Series 5W-30 Synthetic Motor Oil

Amsoil Signature Series 5W-30 100% Synthetic Motor Oil is a high performance motor oil that is known for its industry leading standards.

Its breakthrough formulation helps protect the engine with supreme lubrication and drastically reduces the wear and tear of the engine parts.

AMSOIL Signature Series Synthetic Motor Oil has consistently outperformed the mainstream engine oils in the Four-Ball Wear, Total Base Number and Cold Crank Viscosity Tests as well as impressive results in the NOACK and TEOST Tests, proving Signature Series Synthetic Motor Oil’s excellent high-temperature performance.

With an outstanding range of over 25,000 miles before having to be drained, it has successfully beaten all the other engine oils in the market. It also improves fuel economy by over 6% as per expert claims.

While it is compatible with all other synthetic oils, excessive adulteration may lead to a drop in the performance of the oil. While it is compatible with both old and new engines, it can only be used for gasoline engines.

Its 5W-30 grade viscosity helps ensure that your engine doesn’t splutter in temperatures as low as -50 degree Celsius.

While it is indeed one of the most expensive oils in the market, its class leading features adequately justify its price.

If you are an avid motorist, confident of extensively driving upto 25,000 miles a year, this is the best oil you could opt for.


2) Mobil 1 Extended Performance Extended Performance 5W-30 Motor Oil:-

Mobil 1 Extended Performance Extended Performance 5W-30 Motor Oil

Mobil 1 Extended Performance Extended Performance 5W-30 Motor Oil is a superior high performance motor oil which designed to enhance the performance of your favourite ride.

Its patented formulation with added anti-wear additives helps protect your engine from corrosion as well as wear and tear. It helps extend the life of your engine and keeps it at its best shape.

It has great thermal and oxidation technology which helps boost fuel economy as well as reduce engine noise.

A high concentration of detergent additives help neutralise the acids formed as a by-product of combustion and makes the engine resistant to rust and corrosion.

These features help increase the drain range to over 15,000 miles and considerably reduce the cost of engine oil replacement. Its 5W-30 grade viscosity helps ensure that your engine starts without much effort on winter mornings even in sub-zero temperatures upto -40 degree Celsius without facing issues such as spluttering.

Priced at a premium, it is ideal for high performance engines rather than day to day use. However, if you are a motorist who likes to push his ride to the maximum, this is indeed an oil which can be considered.


3) Royal Purple 51530 High Performance Motor Oil 5W-30:-

Royal Purple 51530 High Performance Motor Oil 5W-30

Royal Purple 51530 High Performance Motor Oil 5W-30 is a high performance synthetic oil that is ideal for motor owners who want to enhance the performance of engines.

Its unique formulation with its patented Synerlac Additive Technology that forms a secure layer around moving parts helps drastically reduce friction while providing superior protection from corrosion as well as wear and tear.

Another unique feature is the compatibility of this oil with any synthetic and conventional oil without any problems.

Further, its unique purple colour helps make detecting leaks much easier than in other oils. With a mileage of 12,000 miles before requiring to be drained, it is safe to call it an annual oil that requires to be changed once a year with general use.

It is a versatile synthetic oil which can be used in gasoline as well as diesel engines. It is also known to boost the fuel economy of your vehicle by upto 4.5%. Its 5W-30 grade viscosity helps ensure that your engine starts without much effort on winter mornings even in sub-zero temperatures without spluttering.

However, its expensive pricing makes it unaffordable for many buyers. However, if you are an avid motorist who spends extensive hours in the vehicle, it is indeed a great option to opt for.



Going by the performance parameters, AMSOIL stands out as the clear winner with its class leading features. So, if you a driving enthusiast who is confident of clocking 25,000 miles annually, it is the best engine oil that money can get. You might even save some money due to the reduced number of oil change that would be required.

However, for more general users, with its economic pricing, Royal Purple seems to be the more reasonable buy of the three.

It provides a great alternative with an interesting range of features to ensure that your engine stays robust with an increased life span without burning a hole in your pocket.

As for Mobil 1, it is priced almost as high as AMSOIL, so it is better to shell out a little more and go for AMSOIL itself.

It is more suited for Mobil 1 loyalists who prefer to go with the brand value of Exxon Mobile rather than any specific performance parameters or for motorists who indulge in high performance competitive racing.

So, as the conclusion, AMSOIL is definitely a winner, but it is always better to make your choice based on your personal requirements rather than to simply go with the one with the best specifications.