Shell Rotella T4 vs T6: Best Oil Comparison in 2023

Every engine that is made experiences friction when running. This can generate heat, cause wear on the engine parts, and reduce the overall performance of your vehicle. That is why you need to choose the right engine oil for you.

Shell is one of the top brands in the world that makes engine oils. They are made using cutting-edge technologies to ensure that your engine is lubricated and protected properly.

Shell’s Rotella T series engine oils have been well known to provide premium protection against wear and temperature. These engine oils are ideal for trucks and SUVs.

Also you can read our related article on: Shell Rotella T5 vs T6: Which One Should You Choose?

Rotella T4 and T6 are two of the prominent products of the Rotella T series. So, let us compare to determine which engine oil is best for you.

The main reason we are making this comparison is that you need to choose the right engine oil that has the exact additives you need. This will ensure that you are utilizing what you are paying for and your engine gets the best treatment possible.

Rotella T6 vs T4: Quick Overview

Shell Rotella T4 versus T6: Detailed Comparison

Let us take a deep look into the extended comparison and find out which one is the best oil for your dream car.

Overview 

Rotella T4

Rotella T4 engine oil is a conventional 15W-40 diesel engine oil that has Triple Protection technology. This will protect your engine from wear, deposits, and oil breakdown.

This engine oil is formulated with advanced additive technologies, which improve deposit control and provides excellent engine cleanliness when you are draining your engine oil.

This oil has enhanced protection against oil oxidation and has stability for better viscosity control and ideal engine oil pressure.

This oil meets the API CK-4 requirements. So, this will improve the performance of both new and old engines.

This engine oil performs exceptionally well for a wide range of heavy-duty engine applications.

Rotella T6

Rotella T6 is another synthetic engine oil that comes with Triple Protection Technology to protect your engine against wear, deposits, and oil breakdown, and improves oil flow at low temperatures.

This will improve the fuel economy of your vehicles by 1.5 percent without compromising the protection and durability of your engine.

The multi-functional dispersant additives present in Rotella T6 provide much better protection against soot, dirt, and other contaminants compared to its predecessors.

This oil has better cold-cranking properties and low-temperature pump-ability. So, this oil will reach your critical engine parts faster.

The low ash formulation will help in protecting the exhaust catalysts and particulate filters that are found on the latest vehicles that have low emissions.

Oil Type

Since Rotella T4 is conventional engine oil, it means that the base oil is a form of petroleum (mineral oil). Special additives are added to this oil to improve viscosity, wear protection, etc.

The benefit of buying this engine oil is that you can get it for a much lower price. Plus, mineral oils naturally have better solubility.

Rotella T6, on the other hand, is a fully synthetic oil. According to Shell’s site, Rotella T6 is made using gas to the liquid base oil.

This improves low-temperature flow and provides several times better protection compared to conventional oils. This affects the price of the oil, and the cost difference between Rotella T6 vs. T4 is apparent.

Additives

Both Rotella T4 and T6 contain anti-wear, advanced multi-functional dispersant additives, detergents, and antioxidants.

Engine Cleanliness

Rotella T4 contains antioxidants, so it provides great protection against oxidation and sludge buildup. However, since this is mineral oil, it contains impurities, and may not clean engine sludge at extreme conditions.

Whereas Rotella T6 is fully synthetic engine oil. It means that it automatically protects against sludge buildup due to its nature. Other than that, it also contains additives like antioxidants.

So, this will not only keep your engine clean but also ensure that no sludge is formed in the future.

In this segment, Rotella T6 takes the win.

Protection Against Leaks

Rotella T4 is mineral oil with additives that protect against leakage. While T6 has similar additives, since it is synthetic oil, there is a high chance of the oil flowing out in case there is a leakage.

Lasting Power

Shell Rotella T4 is backed by Shell 10-year or 300K mile protection. It means you need to change your engine oil once every 300,000 miles or 10 years.

Shell Rotella T6 has better lasting power as it is backed by Shell 10-year or 500K mile protection. So, change your engine oil once every 10 years or 500,000 miles.

Viscosity Grade

Shell Rotella T4 is available in viscosity grades 15W-40 and 10W 30. This means they will have viscosities of 15 and 10 in winter and 40 and 30 respectively in normal temperatures.

So, they are not ideal engine oils for extremely cold temperatures but work well in high temperatures.

T6, however, has viscosity grades 5W-40 and 15W-40. So, you will get a viscosity of 5 at cold temperature. This is better as this will improve the oil flow at extremely cold temperatures.

Price Comparison

A jar of 2.5 gallons (320 fluid ounces) of Shell Rotella T4 15W-40 costs $54. A jar of 2.5 gallons of Shell Rotella T6 costs $85.

Supported Vehicles

Shell Rotella T4 is ideal for diesel vehicles like pickup trucks, vans, tractors, semi rigs, and construction vehicles.

Rotella T6 is supported by diesel engines installed in pickup trucks, vans, tractors, semi rigs, construction vehicles, and motorcycles.

Customer Reviews

Rotella T4

Now, let us take a look at customer reviews from Amazon.

Rotella T4 has over 2800 ratings and an average of 4.7 stars out of 5. Most of the customers have praised the oil quality and value for money. Plus, a lot of reviews have also appreciated the performance of this oil.

Some people have complained that this oil gives a burnt oil smell, and some companies like Ford don’t recommend users to apply this engine oil.

Rotella T6

Rotella T6 has over 5,000 reviews with a global rating of 4.8 stars out of 5. Customers have given high ratings on the longevity and mileage of the oil. There are also high ratings on value for money and sheerness.

The only complaint that we saw was related to poor packaging.

Shell Rotella Pros

Rotella T4

• This is mineral oil, so it is cheaper and has better solubility.
• Has excellent viscosity control and maintains ideal oil pressure.
• Has excellent protection against leakage thanks to the detergent additives present in it.

Rotella T6

• Fully synthetic oil.
• Keeps your engine clean and forms a layer to prevent sludge build-up.
• Has better lasting power compared to T4 (500,000 miles)
• Ideal viscosity for vehicles operating in winter.
• Suitable for motorcycles

Shell Rotella Cons

Rotella T4

• It contains some impurities. So, sludge protection is not ideal.
• The viscosity is not ideal for vehicles operating in extreme cold
• Not suitable for motorcycles

Rotella T6

• Expensive compared to Rotella T4.
• Higher chance of oil coming out in case of a leak in the engine

Frequently Asked Questions (FAQs)

Now let us find answers to questions that may come to your mind when comparing Shell Rotella T4 and T6.

Q. Is Rotella T4 good for diesel engines

A. Rotella T4 is a mineral oil that has the right additives to consider it an ideal engine oil for diesel engines.

Q. Is Shell Rotella T4 Fully Synthetic?

A. No, Rotella T4 is not synthetic. It is a mineral oil that contains a mixture of other additives like detergents, antioxidants, etc. Rotella T6, on the other hand, is fully synthetic.

Q. How many miles is Rotella T4 good for?

A. The Rotella T4 has Shell 10 years or 300K protection. So, Rotella T4 is good for 300,000 miles.

Q. Which Rotella oil has the most zinc.

A. Rotella T4 15W-40 has 1130 ppm of zinc. Rotella T6 15W-40 engine oil has 1095 ppm of zinc. So, T4 has the most zinc.

Q. Which Rotella is the best?

A. As far as the comparison we have done above, Rotella T6 wins in most of the segments, like lasting power, viscosity, etc. So, this oil can be considered the best engine oil.

But you need to keep in mind that it has poor protection against leakage and is more expensive.

Q. Can you use Rotella T6 in a gas engine

A. According to the official site of Shell Rotella, you can use T6 in gas engines.

Final Words

So, we have compared Shell Rotella T4 vs T6 in different fields like additives, cleanliness, lasting power, etc. From here, we can observe that –

Rotella T4 is a mineral oil that has additives that will help in protecting and improving the performance of your engine. Plus, it is pocket friendly.

Being a natural oil, it has better solubility and better protection against leaks. But these are the only things where Rotella T4 excels.

T6, on the other hand, provides better engine protection, keeps your engine clean, and prevents sludge buildup. Thanks to its viscosity rating of 5W-40, it can maintain oil flow even at very low temperatures.

This engine oil needs to be changed after 500,000 miles, compared to T4’s 300,000 miles, plus this oil is suitable for motorcycles and gas engines as well.

The only notable drawbacks are that it is a bit expensive, and the oil is more likely to flow out in case of an engine leak.

So, if cost is not a factor to you and you are confident that you can keep your engine safe, then you can go for Shell Rotella T6.