Shell Rotella T4 vs T5 vs T6

In the engine oil business, Shell has been a pioneer and one of the superior and successful manufacturers. Their engine oils are produced using the most advanced techniques and up-to-date technologies to ensure a perfectly balanced motor oil for your car. Let’s talk their three famous.

1. Shell Rotella T4: The Shell Rotella T4 15W-40 is hands down the most popular engine oil among the Rotella series of Shell. Surprisingly It can prove to be an excellent choice for both heavy-duty diesel engines and modern low emission engines. It is a conventional motor oil

2. Shell Rotella T5: The Rotella T5 that comes in two viscosity grades 10W-30 and 15W-40 is a synthetic blend of heavy-duty engine oil that uses a combination of synthetic base oils and state-of-the-art additives. It can withstand extreme weather conditions especially in winter and help protect your engine.

3. Shell Rotella T6: This engine oil comes in three viscosity grades 15W-40, 5W-40, and 0W-40, and is fully synthetic combined with the finest additives. It can help provide excellent fuel economy and promises a long engine life.

Shell Rotella T4 vs T5

SpecsRotella T4Rotella T5Rotella T6
  Oil Type  Conventional    Synthetic Blend  Fully Synthetic
Engine Type  Gasoline/Diesel    Gasoline/Diesel  Gasoline/Diesel
Viscosity GradeSAE 15W-40 SAE 10W-30SAE 10W-30 SAE 15W-40SAE  0W-40 SAE 5W-30 SAE  5W-40 SAE 15W-40
APICK-4, CJ-4, CL-4 PLUS, CL-4, CH-4  CK-4, CJ-4, CL-4 PLUS, CL-4, CH-4CK-4, CJ-4, CL-4 PLUS, CL-4, CH-4
Price$12 for one Gallon$18 for one Gallon$30 for one Gallon
  Oil Change Frequency    Up to 3000 miles  5000 to 7500 miles  7500 to 15000 miles
AdditivesAnti-wear, Advanced multi-functional Dispersant additives, Detergents, Antioxidants.Anti-wear, Dispersants, Detergents, Antioxidants.   Anti-wear, Detergents, multi-functional dispersent additives, Antioxidants.

Now that you know about the specifications of the three motor oils. Let us look into details to help decide the best engine oil for your vehicle.

Shell Rotella T5 vs T6

Type of Oil:

When comparing different motor oils, the first step is to determine the oil type. Is it conventional oil or synthetic motor oil?  Making this observation is very important as the base oil makes up to 80 percent of the motor oil.

Rotella T4: The Rotella T4 is a conventional engine oil which means it is a redefined form of petroleum with added additives to enhance certain properties like viscosity, anti-wearing, etc. The biggest advantage of choosing a conventional engine oil like the Rotella T4 would be that it costs about 10 percent less than synthetic and semi-synthetic oils. But it also comes with a disadvantage. They are very ineffective in extremely cold weather.

Rotella T5: This motor oil by Shell is a semi-synthetic or a synthetic blend oil. Made by combining conventional and synthetic engine oil, this semi-synthetic engine oil can provide much longer oil change intervals compared to conventional and fully synthetic oils.

Rotella T6: A fully synthetic engine oil that can be used in extreme weather conditions without any problems. Like any synthetic engine oil, it provides excellent engine protection but is relatively expensive.

Take a look at your vehicle’s manual and make up your mind about what kind of motor oil suits it the best.


All the Rotella motor oils have almost the same type of additives used in them. The proportions and processing formula are different but they all share the same additives.

Rotella T4: Anti-wear, Advanced multi-functional Dispersant additives, Detergents, Antioxidants.

Rotella T5: Anti-wear, Dispersants, Detergents, Antioxidants.

Rotella T6: Multi-functional dispersant additives, Anti-wear, Detergents, Antioxidants.

rotella t4 viscosities
Shell Rotella T4 Available viscosity grades

Effect on Engine Performance:

Reduction of Sludge Build Up:

As a result of oxidation in the engine, sludge build-up occurs which can contaminate the engine thus causing damage to it. Good motor oil reduces sludge build in the engine. The Rotella motor oils use the following detergent additives to clean engine sludge.

DetergentsT4 15W-40T5 10W-30T5 15W-40T6 5W-40T6 15W-40

Rotella T4: The Rotella T4 uses an advanced anti-oxidation technology that protects against the oxidation process in the engine hence reduces sludge.  According to our observations, it can clean engine sludge but not that effectively under severe conditions.

Rotella T5: It provides better cleanliness of sludge build-up in the engine. Exceptional deposit control technology ensures greater protection against sludge even under high temperatures.

Rotella T6: It provides the best protection against sludge build-up due to its synthetic nature. It comes with advanced multi-functional dispersant additives that are combined with the synthetic base oil to specifically clean any sludge inside your engine as well as protect it against further sludge build-up.

Our Pick: Rotella R6!

The Rotella R6 proves to be the best engine oil when it comes to sludge reduction.

Engine Seal Protection:

Detergents in motor oils are also responsible for protection against leakage in engine seals. All three Rotella engine oils offer this protection.

But one thing we noticed is that if there was already a leakage present in the engine seal, the Rotella T6 and T5 leaked faster as compared to the Rotella T4. It is because synthetic and half synthetic engine oils are most likely to leak compared to conventional ones.

Our Pick: Rotella T4!

Engine Wear Off Protection:

To determine which oil has the best protection against engine wear, we first have to break down the anti-wear additives present in each of the oil.

Anti-wear additivesT4 15W-40T5 10W-30T5 15W-40T6 5W-40T6 15W-40

Rotella T4: The Rotella T4 uses three anti-wear additives: Boron, Phosphorous, and Zinc.

Rotella T5: The T5 uses an additional anti-wear additive called Molybdenum along with the three the Rotella T4 uses.

Rotella T6: The Rotella T6 uses Boron, Phosphorous, and Zinc but there is a single trace of Molybdenum in it.

A lot of people believe that more zinc in a motor oil means added protection but that is not quite true.

You need to have a balanced amount of each chemical. Boron and Phosphorous go hand in hand to offer wear protection.

All three of these motor oils provide decent anti-wear protection but T6 stands out the most because of its new and improved formula compared to the old formula of T4 and T5 for engine protection.

Our Pick: Rotella T6!

Improved Fuel Economy:

Reduction in sled build-up can cause the vehicle’s engine to perform more efficiently. As a result of this, it uses less fuel and covers more distance.

The Rotella T5 and T6 both are better than the T4 in this regard. They both don’t contain waxes in them unlike the Rotella T4 so they don’t become thick when sitting around in a vehicle. When you start the vehicle the engine oil, gear lube, and transmission fluid don’t require much effort to flow around the engine. This results in less consumption of energy hence improved fuel economy.

Our Pick: Rotella T5 and T6!

Rotella t5 viscosity grades
Shell Rotella T5 Available viscosity grades

Catalytic Converter Performance:

The Rotella motor oils can be harmful to catalytic converters in the long run. A lot of people use them regardless, but keep in mind they have a lot of Phosphorous added to them as an additive. Phosphorous is known to damage catalytic converters in vehicles especially if your engine burns a lot of oil.

Our Pick: None!

There are better and safer engine oils available to protect your catalytic converter.

Oil burn-off protection:

All three Rotella motor oils provide great oil burn-off protection due to the additives present in them. You can rely on any of the three to provide you protection against oil burn-offs.

Our Pick: All three

Viscosity Comparison:

Whenever you compare different motor oils together, you come across these different codes written on the product labels. These codes are there to point out the viscosity grade of the motor oil.

In every code, there are two numbers. The first number has W written after it. The ‘W’ actually stands for winter. This number preceding W defines the viscosity of the oil at a cold temperature like on startup of the engine. The second number stands for the viscosity of the motor oil at high temperatures.

At a low temperature, the viscosity of the oil is thin and it flows easier to protect the engine, and at a high temperature, oil viscosity increases, maintaining film strength that protects the engine.

The viscosity grades of the Rotella Oils are as follows:

Rotella T4: The Rotella T4 is available in the viscosity grade 15W-40 which means it has a viscosity of 15 at low temperatures and a viscosity of 40 at normal or high temperatures.

Rotella T5: It comes in two multi-grade viscosities 15W-40 and 10W-30. So, the first variant can flow with a viscosity of 15 at low temperatures and 40 at high temperatures and the second has a viscosity of 10 and 30 at low and high temperatures respectively.

Rotella T6: The Rotella T6 comes in two multi-grade viscosities as well. The first one is 15W-40 meaning viscosity of 15 at cold temperature and a viscosity of 40 at high temperature. The second is 5W-40 which means it has a viscosity of 5 at low and a viscosity of 40 at high temperature.

Different engine oils work better in different temperatures. For cold temperatures, the Rotella T5 and T6 would be the better choice because they provide enhanced oil flow properties at low temperatures to help protect your engine meanwhile the T4 would work best in extreme heat.

Our Pick: Temperature-dependent.

Oil Change Frequency Comparison:

Oil change frequency refers to the number of miles a vehicle can run before the motor oil needs to be changed.

Rotella T4: It provides an oil change frequency up to 3000 miles which is pretty impressive for conventional engine oil.

Rotella T5: The Rotella T5 provides an oil change frequency of 5000 to 7500 miles.

Rotella T6: Rotella T6 provides the best oil change interval of 7500 up to 15000 miles. Synthetic motor oils are known for their impressive long oil change intervals and the Rotella T6 is no exception.

Our Pick: Rotella T6!

rotella t6 viscosity grades 1
Shell Rotella T6 Available viscosity grades

Cost Comparison:

Rotella T4: Rotella T4 costs $12 for One Gallon and $32 for 2.5 Gallon

Rotella T5: Rotella T5 costs around $18 for One Gallon and $58 for 2.5 Gallon.

Rotella T6: Rotella T6 costs $30 for One Gallon and $68 for 2.5 Gallon

Our Pick: Rotella T5!

The Rotella T5 proves to be the most value for money option here since it provides the qualities of synthetic oil for a much less price tag.

Video Comparison of Shell Rotella T4 vs T5 vs T6


After reading the detailed comparison, you can see that each engine oil has its Pros and Cons. One is better in one aspect while the other is better in another aspect.  There are a lot of other great and better than Rotella engine oils available in the market but if you are a Shell fanboy and only buy Shell motor oils then we are sure this guide has helped you weigh out the differences and decide upon your next motor oil.