Shell Rotella T6 vs Royal Purple HP

T6 and HP are both wholly synthetic where T6 is made to be used for heavy-duty diesel engines while HP is used for passenger car gasoline and light-duty diesel engines.

T6 has improved wear prevention due to its strong anti-wear additives. Its multi-functional detergents don’t allow the build-up of any deposits. Its special formula allows a great performance in cold weather, allowing it to flow freely up to a large range of negative temperatures. It contains silicon as an anti-foam which benefits the smooth functioning of the engine. There are many base additives included in this oil, increasing its TBN. This causes the elongation of the oil change intervals, resulting in a lesser oil exchange rate.

Check out the Comparison: Rotella T4 vs T5 vs T6

HP is a more catalytic converter-friendly oil that approaches with safeguard versus the damage caused while starting the vehicle. It has great oil burn-off protection since its flash point temperature is much higher. This reduces oil consumption and improves fuel economy. It provides higher kinematic viscosities at both the medium and higher temperature, ensuring better lubrication.

Evaluation Table

DescriptionsRotella T6 (0W-40)Royal Purple HP (0W-40)
Type of the motor oilEntirely SyntheticEntirely Synthetic
Types of engines compatibleDiesel onlyPetrol and Diesel
Viscosity Grades commercially available0W-40, 5W-30, 5W-40, 15W-400W-20, 5W-30, 10W-30, 0W-40, 5W-40, 5W-20
Cost (1 Quart) 7.50$8.49$
Oil change regularity (Miles)1500012000
ACEAE9A3/B4, A3/B3

Thickness Difference

Kinematic thickness is the extent of the engine oil’s power to transmit motion all the way through it. An elevated kinematic viscosity is superior at all temperatures which means a lower amount of internal resistance in the oil. Viscosity index tells us about the influence of temperature variations on the kinematic thickness of the motor oil. A higher value of the viscosity index indicates the smaller the temperature-controlled alterations in the kinematic thickness. Pourpoint temperature of fluid is the temperature lower whom it will seize to drift, in normal conditions.

HP possesses upper kinematic viscidness at both middle and high-level temperatures of 40° plus 100° C. This signifies that it is a better oil in terms of kinematic viscosity. Because it holds a lower impact of temperature shift, that’s wherefor this oil’s viscosity index is greater. However, in freezing conditions, T6 excels in terms of performance because of its lower pourpoint temperature.

Comparison of oils (0W-40 Oil Grades)Kinematic Viscosity at 40 o C (mm2/s)Kinematic Viscosity at 100 o C (mm2/s)Viscosity-Index (VI)Pourpoint Temperatures (Degrees Celsius)
Rotella T67513.2179-51
Royal Purple HP79.914.3182-40

Oil Change Rate of recurrence Association

The base extracts within the motor oil are used to offset the acids created in the course of the burning procedure. Their higher quantity ensures the long oil drain intervals and a lower oil change frequency. They are measured as the total base number or TBN.

T6 gets a superior TBN which allows it to achieve an oil change interval of 15,000 miles. On the other hand, HP with a slightly lower TBN provides a lower oil change time of 12,000 miles.

Oils in Assessment (0W-40 Grade oil)Total Base Number (mg of KOH/g)
Rotella T68.6
Royal Purple HP8.2

Difference of Catalytic Converter Execution

The slag developed by the oil-burning mostly consists of ZDDP compound remains. This ash is liable for impeding catalytic converter as well as hampering its functioning.

After testing we found that HP has lower masses of phosphorus and zinc, meaning that it will generate a lesser mass of powder after burning up and is more fitting to be utilized along by catalytic converter.

Motor Oils in Assessment (0W-40 Grade oils)Zn Conc. (ppm)P. Conc. (ppm)
Rotella T611811125
Royal Purple HP832686

Slurry Construct Lessening Analogy

Slurry is a suspension that is formed by the combination of tarnished engine oil, moisture, dust, and additional impurities within the engine oil. It can stop the pipelines transporting oil toward the engine, therefore, poses a great threat. Detergents have been put into the engine oil to remove this sludge.

T6 has a significantly higher total of calcium while its magnesium quantity is slightly higher than its counterpart. An equal measure of sodium exists in both oils. This allows T6 to excel in sludge reduction due to the comparatively higher quantities of detergents. It also has an edge over its equivalent in conditions of anti-foam, as HP has no silicon.

Oils in Assessment (0W-40 Grade oils)Na Concentration (ppm)Mg Concentration (ppm)Ca Concentration (ppm)Si Concentration (ppm)
Rotella T672021334
Royal Purple HP71818220

Evaluation of Motor Oil Burn-off Safeguard

Flash Point indicates the temperature at which the vapors of a liquid can be ignited non-continuously. If an oil has an elevated figure of simpler bits, then it will evaporate quickly and achieve flashpoint at a shorter temperature and the other way around.

Since HP has a higher flashpoint temperature, this means it will evaporate slowly and will deliver improved engine oil burn-off defense.

Oils 0W-40 grade in comparisonFlashpoint Temperature (Degrees Celsius)
Rotella T6226
Royal Purple HP241

Contrast of wear and tear Safety

Anti-wear and tear additives form an oil film across the engine parts, preventing there contact together with one another. This reduces the friction which is responsible for wear and tear inside the engine.

T6 has above average masses of major wear removing additives phosphorus and zinc, whereas the HP has higher quantities of secondary additives boron and molybdenum. T6 due to the collectively higher anti-wear additives quantity is more beneficial in conditions of preventing wear. It will produce a broader and stronger oil film to aid the lubrication of the engine parts.

Oils in Evaluation (0W-40 Grade oils)Zn Concentration (ppm)P Concentration (ppm)B Concentration (ppm)Mo Concentration (ppm)
Rotella T611811125495
Royal Purple HP8326867243

Brief Summary

  • These motor oils are both synthetic where HP is used for both gasoline and diesel engines while T6 is only suitable with diesel engines.
  • HP is an additionally catalytic-pleasant oil due to the presence of lower quantities of zinc and phosphorus.
  • The sludge reduction ability of T6 is higher due to higher quantities of detergents as compared to its counterpart.
  • T6 has anti-foam agent silicon.
  • HP is less volatile since it has a greater flashpoint temperature than T6.
  • Anti-wear additives are present in higher quantities in T6 as compared to that in HP.
  • HP has higher kinematic thicknesses at 40° C as well as 100° C along with the higher viscosity index.
  • T6 performs better in chilly weather owing to its lower pour point temperature.
  • TBN of T6 is higher, allowing longer oil change intervals.
  • T6 is not expensive and extra expense-valuable than its competitor.