Quaker State Advanced Durability VS Castrol GTX

Unlike most modern oils Quaker State Advanced Durability and Castrol GTX are both conventional oils made for gasoline engines, where Quaker state provides high durability during extreme operating conditions while GTX focuses on efficiently cleaning of the engine.

Quaker State is more reliable for engines operating under high-temperature conditions, as this oil can effectively resist the breakdown at such temperatures. Since this oil doesn’t get oxidized, its evaporation rate will be lower, providing a better fuel economy. It is most effective at higher temperatures, offering higher viscosities and viscosity index. It is loaded with bases, increasing its TBN a lot and allowing longer oil change intervals.

GTX, on the other hand, has superior deposit protection due to its “TriShield Technology” which employs active detergents which attract, capture, and disperse the smaller deposit particles so that they don’t form sludge. It is recommended in cold weather due to its superior performance in such conditions. It has a minimum quantity of anti-wear additives, but they are enough to finish the job. It produces a neglectable amount of ash when burnt, making it an attractive choice for catalytic converter users.

Comparison Table

FeaturesQuaker State Advanced Durability (5W-30)Castrol GTX (5W-30)
Type of oilConventionalConventional
Engine TypeGasolineGasoline
Viscosity grades available5W-20, 5W-30, 10W-30, 10W-405W-30, 10W-30, 10W-40, 20W-50
Cost (1 Quart)7.52 $5.48 $
Oil change frequency (miles)7,500 to 10,00010,000 to 15,000

Friction Reduction

The friction between the moving engine parts is the main culprit for wear occurrence. The anti-wear additives available in the oil achieve their goal of reducing this friction by forming an oil protection layer around metal parts. This layer acts as a boundary and avoids the direct contact of metal with each other. This is how lubrication is done by anti-wear additives inside the engine.

GTX only has two main anti-wear additives in relatively lower values which are zinc and phosphorus. It has no other anti-wear additives, severely decreasing its capability in this field. While Quaker State along with higher quantities of conventional anti-wear additives has a decent concentration of molybdenum. It also has a somewhat quantity boron to aid in the reduction of friction. This makes this oil highly attractive in terms of reducing the wear caused by friction.

Comparing Oils (5W-30 Grade oils)Zinc Concentration (ppm)Phosphorus Concentration (ppm)Boron Concentration (ppm)Molybdenum Concentration (ppm)Titanium Concentration (ppm)
Quaker State Advanced Durability8467885124<1
Castrol GTX789717<1<1<1

Hot weather performance

When comparing the performance of any oil few parameters are checked like density, kinematic viscosity at different temperatures, and its viscosity index. Density determines the viscosity of an oil, it gets lower by temperature increase and the oil having higher density will have an edge. Kinematic viscosity is the internal resistance of oil to flow while viscosity index is the ratio of kinematic viscosities at higher and lower temperatures.

At a fifteen-degree temperature, the density of GTX is higher but it doesn’t help much as the kinematic viscosities at intervals of 40 and 100 are measured higher of Quaker State, hence its viscosity index will also be higher, showing lower temperature effects.

Comparing Oils (5W-30 Grade oils)Density @ 15° C (Kg/m3)Kinematic Viscosity at 40 o C (cSt)Kinematic Viscosity at 100 o C (cSt)Viscosity index (VI)
Quaker State Advanced Durability0.85768.2511.09155
Castrol GTX0.86261.710.5146

Cold weather performance

When the temperature falls below zero, oil can’t flow efficiently without an external push. Therefore, at such temperature, we measure the oil’s dynamic viscosity which is its ability to resist flow under influence of external force. Whereas the pour point shows the freezing temperature of the oil.

Since GTX has a lower dynamic viscosity, it will flow better at a temperature of minus thirty degrees and also freezes at a lower temperature than its competitor.

Comparing Oils (5W-30 Grade oils)Dynamic viscosity @ -30° CPour point (o C)
Quaker State Advanced Durability6220-33
Castrol GTX5284-39

Effect on Catalytic Converter Performance

The catalytic converter is affected by the ash that gets produced when the oil burns. The main constituents of this ash are anti-wear additives, present in the form of the ZDDP compound. The poisoning of the catalytic converter occurs as a result of ash interaction and its performance gets decreased.

The parts per million concentration of both the phosphorus and zinc were measured in these oil and the test results show the higher concentration of these additives in Quaker State, resulting in a greater quantity of ash generation which will obstruct the catalytic converter from functioning normally.

Comparing oils (5W-30 Grade oils)Concentrations of Zinc (ppm)Concentrations of Phosphorus (ppm)
Quaker State Advanced Durability846788
Castrol GTX789717

Varnishes Removal Ability

The impurities in the oil which are added with time accumulate in the form of sludge and foam, by reacting under certain conditions involving high temperature and pressure. They pose a threat to the operation of the engine by reducing or completely stopping the flow of oil through it, depending upon their quantity.

Quaker State uses calcium whereas GTX depends upon both calcium and sodium to act as detergents and remove sludge. Even though the concentration of calcium is higher in the first oil but the combined concentrations of calcium and sodium in the second oil forms a higher number, making it better for varnishes removal. The magnesium quantity in this comparison is highly insignificant, just for the sake it is found higher in the first oil.

The anti-foam agent prevents the formation of foam which also decreases the efficiency of the oil since GTX has a higher concentration of silicon acting as an anti-foam agent, therefore, it will effectively hinder the build-up of foam.

Comparing oils (5W-30 Grade oils)Concentrations of Sodium (ppm)Concentrations of Magnesium (ppm)Concentrations of Calcium (ppm)Concentrations of Silicon (ppm)
Quaker State Advanced Durability<51122165
Castrol GTX357821898

Evaporation rate

The reason for comparing the evaporation and flashpoint temperature of any oil is to judge the oil consumption rate as the oil which vaporizes quickly will achieve its ignition point at low temperature and will as be consumed earlier. This negatively affects the fuel economy which is inversely proportional to the vaporization rate and directly proportional to flash point temperature.

GTX will be the least fuel-economical, having a higher vaporization rate and a lower flash point temperature.

Conversely, Quaker State is more fuel economical in comparison as it vaporizes slowly and achieves its flashpoint at a higher temperature in respect to its counterpart.

Comparing oils (5W-30 Grade oils)Vaporization rate ()Flashpoint (Degrees Celsius)
Quaker State Advanced Durability13.2212
Castrol GTX14.7200

Oil Drain Interval

Bases act as an anti-corrosive agent for the oil by nullifying the harmful acids produced as a by-product during combustion. A higher quantity of these bases allows the oil to maintain the basic nature of oil for a longer duration, prolonging its oil change interval. TBN is not the only factor influencing the oil change frequency but it’s the major one.

A greater total base number of GTX makes it a long oil change interval oil. It  provides a splendid oil drain interval of 10,000 to 15,000 Miles whereas the Quaker State has an oil drain interval of 7,500 to 10,000 Miles, which is significantly lesser than its counterpart.

Comparing Oils (5W-30 Grade oils)TBN (Total Base Number) mg KOH/g
Quaker State Advanced Durability8.2
Castrol GTX8.4

Price Differences

The prices of both Quaker State and GTX are 7.52 $ and 8.54 $ respectively. A certain hike in the price of GTX is due to its better catalytic converter performance, sludge removal, and cold temperature viscosity. Since Quaker State gives us a superior fuel economy, high-temperature viscosities, viscosity index, and a lower oil change frequency for a slightly lower price, hence, it is preferable in comparison with other oil, for common use, unless you have specific requirements which are only fulfilled by the other oil.

Quick Summary

  • These are gasoline engine oils which are classified as conventional.
  • GTX is more fitted to be used with the catalytic converter.
  • GTX is highly efficient at removing varnishes.
  • A higher fuel economy is offered by the Quaker State.
  • More active anti-wear agents are found in the Quaker State oil.
  • The Quaker State oil leads with a better kinematic viscosity and viscosity index.
  • GTX rules in cold conditions due to its lower pour point temperature.
  • A longer oil drainage interval is possible through Quaker State.
  • Quaker State is budget-friendly and provides a higher value for money.