Castrol GTX Magnatec vs Mobil Super 3000

If your search engine found this article, it is quite a possibility that you care about what your car goes through. Perhaps you want your car’s engine to run all smooth but cannot come to a conclusion. If that is the case, your time and Search engine have brought you to the place just right. Just some reading, and there you know what is the best for your car; Castrol’s GTX Magnatec or Mobil super 3000.

Castrol is a British company established back in 1899, while Mobil Oil was established in 1974 in the United States. With both the companies having quite an experience in their jobs for quite an amount of time, it might be a troubling decision to choose one. That is where the details kick in. Without further ado, let us get into it.

Compare Castrol Magnatec with Shell Helix Ultra
Compare Castrol Magnatec with Castrol GTX

Oil Type Comparison:

It might ease you off to know that Castrol GTX Magnatec comes to you, not from the dirt-laden areas that might add to the impurities in your engine but it comes from the clean labs. The oil is free of the impurities that might affect its ability to work or constantly be an issue for your car.

And how do we know that? Through the company’s claim of it being fully synthetic.

When it comes to Mobil Super 3000, we are sorry to put you back in the trouble of decision making. This oil, too claims to be free from the impurities that could damage your engine.

The good news is, both the oils are synthetic.

The bad news? You might have to read on to get to the conclusion.

SpecificationsCastrol GTX MagnatecMobil Super 3000
Oil typeFully syntheticFully synthetic
Engine typeBoth Gasoline and DieselBoth Gasoline and Diesel
Available viscosity gradesSAE 0W-20, 0W-40, 5W-30, 5W-40, 10W-40, 15W-40, 20W-50.SAE 5W-40, 5W-30
Cost4.97 US dollars per liter1.7 US dollars per liter
Oil Change frequency10000 kilometers20000 kilometers
Comprison of Castrol GTX Magnatec & Mobil super 3000

Additives Comparison:

There is a simple rule. As the oil circulates in the engine, it is going to give out the waste products and sludge.

The companies have thought it through and they came up with the solution of adding the additives. So, what is it that is going to save your engine from all this mess?

It is a variety of compounds that might include antioxidants, anti-wear, detergents, dispersants, pour point depressants, viscosity modifiers, and rust and corrosion inhibitors. 

Mobil Oil claims the presence of ‘high-performance additives’ that will definitely fight off the sludge and protect your car’s engine.

Castrol Oil, with its claim of ‘it is not just oil, it is liquid engineering’ and its new product Castrol Magnatec claims 1.4 times better protection from the sludge.

And what is making that happen? The ‘add-ons’.

mobil super 3000
Mobil Super 3000 viscosity grades.

Engine Performance Comparison:

We will look at the engine performance from different aspects.

Catalytic Converter Performance

Oils are made of heavy compounds. They do not burn off that easily. But because the oil has to face temperatures pretty high, quite an amount of its vapors may form and can affect the catalytic converter you just installed. One of the components of the oil that proves to be the most toxic for the catalytic converters is phosphorous.

Mobil Super 3000 engine oil has a phosphorous content that weighs up to 0.05 percent. The presence of phosphorous in the oils is inevitable. Even in the fully synthetic ones. But it won’t do much harm if the amount of phosphorus in the oils is taken care of and is brought down to as little as this.

The phosphorous content in the Castrol GTX Magnatec oil has, however, been found to be about 0.1 to 0.12 percent. That is double the amount present in Mobil Super 3000.

Guess that is where the Mobil Super 3000 takes a win.

Reduction of sludge build-up

Another way the engine oil may prove to be harmful to your engine is by the oxidation of its compounds under the high temperature that the working condition of the engine provides. The coolant here does more harm than good. It, along with the oxidized carbon molecules forms thick sludge.

To prevent the sludge built up, there are two things we can do:

  • Prevent the formation of sludge by adding antioxidants
  • Wash away the sludge once it is formed by adding the detergents

Castrol GTX Magnatec claims 1.4 percent better protection from the sludge build-up because of the better additives that are added in.

Mobil Super 3000, too, claims excellent protection from the sludge build-up. However, the exact values for its protection have not been provided, as such.

Oil Burn-off Protection

Castrol GTX Magnatec has an important claim when it comes to oil burn-off protection. When your car runs through the runway, its engine goes through several stages right from the start where it has to deal with the extreme temperatures. The critical warm-up temperature when the engine wear reaches up to 75 percent is when Castrol GTX Magnatec claims to protect the engine.

The technology that has been introduced in the formula does not let the heavy molecules of the oil evaporate. As fewer vapours evaporate even when the temperature reaches the peak, less oil is lost. As a result, the engine oil added to the engine can protect it for a longer duration of time.

Mobil Super 3000, too, does not stay back in this field. It claims most of its oil maintaining its normal liquid form under temperatures as high as 4000 degrees Fahrenheit. And that too, without the oxidative breakdown of any sort.

Minimizing Engine Wear off

This is one of the main reasons why the engine oils were made in the first place. To minimize the engine wear off. So, if all the oils provide the lubrication and prevent the friction from damaging the engine as it works, what is it that makes Castrol GTX Magnatec distinguished?

The DUALOCK technology.

It defies its very liquid quality of flowing wherever the place is and has been carefully engineered to cling to the important parts of the engine (or the parts where the wear is highly imminent). The molecules of the oil do not only cling to the engine but also each other.

This makes a thick, unbreakable layer on the surface of the parts of the engine. And this, in specific, reduces the start-stop wear of the engine.

Hence, the oil has been known to have reduced engine wear up to 50 percent.

Mobil Super 3000 has been shown to have rapid oil circulation. This is what prevents the critical parts of the engine from getting affected, especially in cold weather. Rapid circulation of the oil gives a chance for all the parts of the engine to be well lubricated, hence protecting it from friction.

Engine Seals Protection

How well protected the engine is, is signified by how well protected the engine seals are and vice versa?

What can protect the seals is the prevention of the sludge build-up.

And once the sludge has formed, it must be dealt with ASAP. How it is dealt with is by the addition of detergents in the oil.

Castrol GTX Magnatec and Mobil Super 3000, both have detergents that act on the sludge and prevent it from depositing on the seal, or on any other part of the engine.

Improved fuel economy

For the engine oil to work for longer periods of time, it needs to:

  • Not get converted into the vapor form
  • Protect the engine from getting harmed
  • Prevent the sludge build-up

Both the companies have very similar claims. But which of them has a better fuel economy, you ask? The oil that is the best for your engine.

Choose wisely.

According to the tests that have been recently run, the oils produced by Mobil have a better preservation quality.

castrol gtx magnatec 1
Castrol GTX Magnatec viscosity grades

Viscosity Comparison:

There is a range of viscosities of Castrol GTX Magnatec these are 0W-20, 5W-30, 5W-40 & 10W-30.

The viscosity of the oil quite obviously has to change for the temperature. So, the figures given above indicate the viscosity of the fuel when the engine is started or in winters. (W stands for winters). And the number written after it indicates the viscosities when the higher temperatures are achieved.

So, the viscosity of Castrol may range from 0 to 20 in cold temperatures. And from 20 to 40 in the higher temperature.

Mobil Super 3000, however, offers these viscosities 0W-20, 0W-30, 5W-30 and 5W-40 which means that its viscosity in winters is 5, but as the temperature rises, it may raise up to 30 or 40, depending on the type of oil you choose.

How frequently will you need to change the oil?

If you choose to use Castrol GTX Magnatec, you won’t have to change it for a good six months or 10000 kilo meters. This means you will only have to take your car for an oil change only twice a year! Sounds like a good deal. Doesn’t it?

But if you have to go through the struggle only once a year, that would be much more convenient. That is what Mobil Super 3000 promises. An oil changes a year or every 20000 kilo meters.

So here Mobil super 3000 takes lead on Castrol GTX Magnatec providing you extra mileage and reducing oil change frequency.

What will either of this cost you?

Castrol GTX Magnatec will cost you around 4.97 US dollars per litre.

While the Mobil super 3000 engine oil will cost you 1.71 US dollars per litre.


There is one thing for sure. Your car’s engine loves to have a fully synthetic engine oil. And with both of the oils being fully synthetic, the competition between the both of them gets pretty close. However, fully synthetic oil with a better fuel economy might looks like a better option.