Motorcraft Synthetic Blend vs Shell Rotella T6

Motorcraft, as the name suggests, is a synthetic blend oil utilized in gasoline engines only.

Here, Shell Rotella T6 is a fully synthetic oil that can be used for both gasoline and diesel engines. Motorcraft focuses on protecting the engine from wearing while T6 mainly emphasizes on cleaning.

Check out the Comparison: Rotella T4 vs T5 vs T6

Motorcraft provides a high catalytic converter performance and is known for its excellent wearing resistance. A noticeable amount of calcium and magnesium-based detergent additives in the oil helps to effectively clean the sludge.

MotorCraft Synthetic blend motor oil

It provides a low variation in viscosity when the temperature is increased because of its high viscosity index. It is budget-friendly due to its low price.

T6, on the other hand, contains high concentrations of detergents and dispersants to clean the sludge diligently. The high flashpoint provides better protection against early burning of the oil. Anti-wearing additives are included in the oil in decent numbers for resisting the problem of engine wearing.

Rotella T6 by Shell

Its performance is very good at both low as well as at high temperatures. It provides excellent fuel economy due to its lower oil-change frequency.

StatementsMotorcraft Synthetic BlendShell Rotella T6
Oil TypeSynthetic BlendEntirely Synthetic
Engine CategoryGasolineGasoline/ Diesel
Obtainable oil viscosity grades0W-20, 5W-20, 5W-30, 10W-300W-40, 5W-30, 5W-40, 15W-40
APISNCK-4, CJ-4, CI-Plus, CH-4, SN
Cost (5 Quarts.)22.98 $48.96 $
Oil exchanging interval (miles)5,000-7,50010,000-12,000
AdditivesDetergents, Dispersants, Anti-wears, Anti-oxidants, Friction ModifiersAnti-wears, Detergents, Dispersants,  

Contrasting Wear Shielding Performance

The wearing and tearing of the engine are lowered by the addition of anti-wearing agents in the motor oil. These additives lower the friction by forming thin layers around the metal parts of the engine minimizing its wearing. A greater quantity of these anti-wearing additives will provide more resistance against wear and tear, increasing life of the engine.

The concentration of main anti-wearing additives (zinc and phosphorus) is high in T6. It also contains slightly more boron-based additives as well.  However, the amount of secondary anti-wearing additive (molybdenum) in Motorcraft is very high compared to T6. Small traces of titanium are also found in both these oils. Overall, Motorcraft provides marginally superior wearing protection.

Contrasting oils (5W-30 Grade oil)Amount of Zinc(ppm)Amount of Phosphorus (ppm)Amount of Boron (ppm)Amount of Molybdenum (ppm)Amount of Titanium (ppm)
Motorcraft Synthetic Blend801747179162<1
Shell Rotella T687278220131

Comparing viscosities of oils

The resistance in fluid movement is referred to as kinematic viscosity. If this kinematic viscosity is high, the performance of the fluid at inflated temperatures will be better. The change in the fluid viscosity on temperature variations is called the viscosity index. A greater viscosity index allows lower viscosity variation upon increasing temperatures. The pour point of the oil decides its performance in lower temperatures. The minimum temperature beneath which it cannot flow.

T6 has a higher kinematic viscosity at both medium (40 o C) and high (100 o C) temperatures providing superior performance at the respective temperatures. However, the Motorcraft provides more stable viscosity when the temperature switch from 40o C to 100o C due to its high viscosity index. In colder environments, T6 performance-wise proved to be ahead of its competitor because of its low pour point.

Contrasting oils (5W-30 Grade oil)Kinematic Viscosity at 40 o C (cSt)Kinematic Viscosity at 100 o C (cSt)Viscosity index (VI)Pour point (o C)
Motorcraft Synthetic Blend66.211.1163-42
Shell Rotella T67512.1159-48

Contrasting the Working of Catalytic Converter

ZDDP ash is formed as a result of oil burning. This ash plunge into catalytic converter, making it poisonous. This toxic catalytic converter won’t be able to function properly leading to its low efficiency.

The formation of toxic ash is lower in Motorcraft due to its lower zinc and phosphorus concentrations. T6 will greatly affect the catalytic converter due to its high quantities of these zinc and phosphorus-based anti-wearing additives. Overall, Motorcraft is faintly more catalytic converter friendly compared to its peer.

Contrasting oils (5W-30 Grade oil)Quantity of Zinc (ppm)Quantity of Phosphorus (ppm)
Motorcraft Synthetic Blend801747
Shell Rotella T6872782

Low sludge formation Comparison

Oxidized oil will react with the different impurities like dirt or moisture and form a black viscous liquid called sludge. This sludge will cause hindrance in engine performance. To minimize this issue, special types of additives known as detergents and dispersants are included in the oil. The presence of these additives in higher amounts will greatly reduce the chances of sludge formation.

Calcium-based detergents are present in large amounts in Motorcraft to lower sludge build-up. It also contains magnesium compounds in good numbers while small traces of sodium are also found in the oil. Silicon, which acts as an anti-foaming agent, is also present in the oil to lower the foaming problems.

T6 contains greater quantities of both calcium and magnesium detergents. The amount of sodium present in the oil is similar to that of its counterpart but it has a relatively high silicon quantity. Due to higher concentrations of these detergent additives, its overall sludge clean-up performance is superior to its counterpart.

Contrasting oils (5W-30 Grade oil)Amount of Sodium (ppm)Amount of Magnesium (ppm)Amount of Calcium (ppm)Amount of Silicon  (ppm)
Motorcraft Synthetic Blend545214296
Shell Rotella T6580012537

Contrasting oil early burning protection

A high concentration of lightweight particles present in the oil increases its volatility. This is due to the early breakdown of these molecules at elevated temperatures. Higher concentrations of these molecules lead to lower protection of oil against pre-burning.

Motorcraft possesses a low flashpoint that indicates its high volatility because of the presence of more lightweight molecules. Meanwhile, T6 provides better protection against early burning of the oil due to its relatively high flashpoint.

Contrasting oils (5W-30 Grade oil)Flashpoint (o C)
Motorcraft Synthetic Blend206
Shell Rotella T6239

Comparing oil exchanging regularity

Base additives are included in the engine oil to neutralize the acids formed during its combustion. The quantities of these additives are estimated from the Total Base Number (TBN). TBN usually decreases over the course of time. If this value drops below one, the oil is required to be changed. Higher TBN will cause lower oil changing frequency.

Motorcraft contains lower concentrations of base additives so it possesses a low TBN and requires to be changed after an interval of 5,000 to 7,500 miles. Conversely, T6 will more effectively counterbalance the acid formations because of its relatively higher TBN providing longer oil exchanging intervals between 10,000 to 12,000 miles.

Contrasting oils (5W-30 Grade oil)TBN mg KOH/g
Motorcraft Synthetic Blend7
Shell Rotella T611

Quick Summary

  • Motorcraft is synthetic blend oil used for gasoline engines only while T6 is a fully synthetic oil that can be utilized for both gasoline and heavy-duty diesel engines.
  • ZDDP ash formation is lower in Motorcraft so it is more catalytic converter friendly.
  • T6 has more detergents to protect the engine from sludge build-up compared to its counterpart.
  • Slightly high concentration of silicon in T6 allows more protection against foaming.
  • T6 has a higher flashpoint providing better protection against early oil burn-off.
  • High concentrations of ant-wearing additives in Motorcraft allow better lubrication and low wearing and tearing of the engine.
  •  T6 performs better at elevated temperatures because of its higher kinematic viscosities at both 40o C and 100o C.
  • Motorcraft has low changes in viscosity when the temperature is increased due to its relatively high viscosity index.
  • T6 provides better cold startups due to its lower pour point temperature.
  • Motorcraft has a higher oil changing frequency due to its lower TBN.
  • T6 is more expensive than its rival because of its better fuel economy.