Rotella T6 5W40 vs 15W40

Rotella T6 5W40 vs 15W40: Which One Is Suitable for You?

Most vehicle owners use different types of synthetic oil to make the vehicle engine more efficient and construct the withstand capabilities in any conditions. Though there are different types of motor oil in the market, but the Shell Rotella T6 full synthetic oil is trendy for its quality and performance.

The manufacturer has made their oil based on different weather conditions. The Shell Rotella T6 5W-40 and 15W-40 are very prevalent at present. Both oils give your engine the ability to cope with different temperatures.

However, the concern is that most consumers are confused about the differences between Rotella T6 5W40 vs 15W40 synthetic oil. So basically, our comparison manual has been created to clear the confusion of consumers and get outstanding performance. Here, we have highlighted all the things part by part.

So without wasting time, let’s start our comparison blog between 5W40 vs 15W40 diesel oil.

Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil Overview

The Shell Rotella T6 5W40 is a perfect option for fuel efficiency as well as the outstanding performance of heavy vehicles. In addition, it gives superior engine protection from wear and is suitable for colder climates. There are also some more cool features which we will discuss below.

Why We Choose It

  • Fuel economy diesel engine oil
  • It protects the engine for a long time with special protection from wear.
  • It is suitable for aggressive driving in extreme conditions, as well as provides better heat resistance.
  • It has better performance in colder weather, especially during engine start.
  • Furthermore, 5W40 provides efficient cleaning, due to which there are no dirt deposits in the engine.

What We Didn’t Like

  • Expensive price range
  • 5W40 are not suitable for worn-out engine

Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil Overview

If you are looking for an older vehicle’s suitable diesel engine oil, then Shell Rotella T6 15W40 is the most suitable option for you. One of the most useful features of this oil is that it gives adequate performance to worn-out engines as well as it is a perfect option for extremely hot weather conditions.

Why We Choose It

  • Budget-friendly price ranges
  • It is suitable for most worn-out engines, which gives the engine protection and provides better performance.
  • Internal combustion provides economic fuel consumption.
  • An excellent option for a warm environment

What We Didn’t Like

  • Its characteristic losses in a lower temperature, due to which it is not suitable for lower temperatures.
  • If you prefer aggressive driving in extreme conditions, it is not able to maintain consistency.

Shell Rotella T6 5W40 vs 15W40 Full Synthetic Oil: Detailed Comparison

Both oils are suitable for different purposes and temperatures, so they don’t have many similar characteristics. However, below we highlight some common differences between both Rotella T6 5W40 vs 15W40.


Most cases are seen by many vehicle owners struggling to start the engine in extremely cold temperatures. Basically, the T6 5W40 has been made keeping in mind the cold temperature, which helps to start the engine efficiently even at an extremely low temperature of low viscosity. The T6 5W40 is extremely thin at cold temperature compared to 15W40, due to which it flows more quickly.

On the other hand, 15W40 provides superior protection to hot climates, sometimes great for cold weather and suitable for both new and old heavy-duty vehicles. Moreover, it is very effective in controlling the engines perfectly.

Fuel Economy

The T6 5W40 is far ahead in terms of fuel efficiency, providing lower fuel consumption as well as 1.5% more fuel-efficient than the T6 15W40. It also has better emissions system compatibility with oxidation resistance and control of oil viscosity.

On the other hand, T6 15W40 also provides better fuel economy, as well as dispersant additives and detergents in oil, providing lower volatility. One of the most useful aspects of the T6 15W40 is its extended drain capabilities, as well as being more fuel-efficient than the conventional T4 15W40.

Shear Stability

The Rotella T6 5W40 motor oil provides outstanding shear stability compared to the 15W40 as well as it resists oil viscosity loss.

On the other hand, Rotella 15W40 motor oil is less shear-stable, but like 5W40, it maintains an optimum level of oil pressure as well as efficiently resists the oil viscosity loss.

Rotella T6 5W40 vs 15W40: FAQs

Is 5w40 better than 15w40?

5W40 is basically the best engine oil to protect the engine from wear and also gives the engine better service for a long time. Moreover, 5w40 oil is said to be the best option for colder weather than 15w40; it helps to start the engine efficiently in colder weather, as well as helps to drive heat resistance and aggression in any extreme weather.

Can we use 15w40 instead of 5w40?

You can never use the 15w40 and 5w40 one as an alternative to the other. Before buying engine oil, you must pay special attention to the temperature of your driving areas. If you are looking for a lower temperature, then you must go 5w40 for outstanding performance.

15w40 is the perfect option for warm weather conditions. So use these oils for an exact purpose, not alternatively.

Which is thicker, 5W40 or 15W40?

5W40 and 15W40 are almost the same viscosity in engine temperature. But in cold weather conditions, 5W40 is much thinner than 15W40, and 15W40 is much thicker.

Final Verdict

The Rotella T6 5W40 vs 15W40 has a significant difference, as we mentioned earlier, the two oils are suitable for two specific temperatures, so there is no similarity between the two. Therefore, before you finally choose engine oil, you must pay special attention to the weather conditions in your area.

If you want to choose engine oil for warm weather, Shell Rotella T6 15W40 engine oil is undoubtedly the most suitable option. And if you are looking for aggressive driving with extremely cold weather, then Shell Rotella T6 5W40 engine oil is a perfect option.

Another important part is that when you decide to use engine oil, you should carefully read the user manual of your manufacturers before using it because most car manufacturers forbid the use of motor oil or engine oil.