Amsoil XL and SS are both completely synthetic engine oil made to be utilized in gasoline engines. XL is used in highly advanced automotive gasoline engines, including those with turbo and direct injection technologies Whereas SS is recommended to be used in engines with Gasoline Direct injection (GDI) Technology.
XL’s formula protects the engine from Low-speed pre-ignition (LPSI) which can damage its pistons. The detergent and other booster additives added into this oil increase its sludge lessening ability and TBN. It provides 25% more cleanliness than other oils of the same company. It is a catalytic converter and economic-friendly oil.
SS is famous for its remarkable 75% extra protection against engine wear compared to the other oils of the same company. It provides extended oil change distances and increases the engine’s life.
Table of Contents
Difference Table
| Requirements | Amsoil XL (5W-30) | Amsoil SS (5W-30) |
| Lubricant Type | Wholly Synthetic | Totally Synthetic |
| Engine Mode | Gasoline/Gasoline direct injection (GDI) | Gasoline (Efficient with the turbochargers) |
| Obtainable thickness grades | 10W-40, 5W-30, 10W-30, 5W-20, 0W-20 | 0W-20, 0W-40, 5W-20, 5W-30, 10W-30, 0W-30 |
| Oil change regularity (Kms) | 19000 | 24000 |
| Cost / liter | 11$ | 14$ |
| API | SN/SM | SN/SM |
| ACEA | A5/B5, A1/B1 | A5/B5, A1/B1 |
| ILSAC | GF-5 | GF-5 |
Comparing Catalytic Converter Efficiency
Generally, the motor oils have phosphorus and zinc compounds used in them as anti-wear and tear agents but when they burn off, these compounds are left behind as ashes, which are poisonous to catalytic converter. Hence a smaller number of following compounds will prove to be beneficial for catalytic converter’s operation.
The value of phosphorus along with zinc is tested to be lower in the XL. Hence, it is best suited to be employed with converter.
By comparison, the SS has a higher amount of anti-wear additives available in it. This makes it highly unsuitable to be used with catalytic converter, as the high concentration of phosphorus as well as zinc will produce a higher volume of dust which will poison the catalytic converter.
| Oils (5W-30) | Zn Concentration (ppm) | P Concentration (ppm) |
| Amsoil XL | 736 | 661 |
| Amsoil SS | 829 | 728 |
Sludge Buildup Lessening Assessment
The dissolved oil molecules break up and combine with other chemicals like dust, water, grease, etc. to form sludge. This thick sludge can block the ducts and hence hinder the engine’s performance. Detergents are used to fight against the sludge.
XL has a combination of magnesium and calcium used as detergents with a slightly lower amount of anti-foaming agent silicon, compared to other oil. It provides a decent sludge reduction but not better than SS.
SS is better equipped comparatively, for fighting against sludge because it has a greater amount of sodium, magnesium, and calcium detergents. A higher volume of silicon is existing in this engine oil to stop the formation of foam.
| Oils (5W-30) | Na Concentration (ppm) | Mg Concentration (ppm) | Ca Concentration (ppm) | Si Concentration (ppm) |
| Amsoil XL | 2 | 918 | 1211 | 5 |
| Amsoil SS | 8 | 959 | 1302 | 7 |
Contrast of Oil Burning Armor
The high temperature of engine’s parts causes the simpler fragments in the engine oil to burn off, hence boosting volatility. This characteristic of the oil is determined by its flashpoint (auto-ignition temperature). An engine oil having superior flash point represents lower volatility and vice versa.
XL has a lesser flashpoint of all the oils, in comparison, indicating it has the maximum amount of light particles which will evaporate quickly in high-temperature conditions. This results in the highest volatility of this oil.
SS with a slightly higher flash point than XL is the better oil in conditions of volatility. It is somewhat more resistive against vaporization compared to its opponents and provides the best oil’s burning guard.
| Motor Oil (Grade: 5W-30) | Flashpoint Temperatures (°C) |
| Amsoil XL | 214 |
| Amsoil SS | 220 |
Evaluation of Engine Wearing Security
To protect the engine parts from wear, anti-wear and tear additives are included in oil which forms a protective film around engine parts, reducing their resistance. A greater quantity of these extracts will result in a thicker film developed around metal engine parts, therefore, improving wear protection.
XL has a lesser amount of anti-wear and tear additives which affects the performance of engine by making it more prone to wear.
SS has a higher concentration of all the anti-wear and tear additives including molybdenum, resulting in a better oil in provisions of anti-wear capabilities.
| Oils (5W-30) | Zn Concentration (ppm) | P Concentration (ppm) | B Concentration (ppm) | Mo Concentration (ppm) |
| Amsoil XL | 736 | 661 | 223 | 73 |
| Amsoil SS | 829 | 728 | 385 | 232 |
Viscosity Assessment
The performance of engine oil is determined by its kinematic thickness (core endurance to drift). A greater kinematic thickness at a particular temperature means better performance. If the oil effectively retains much of its lower temperature kinematic viscosity at a higher temperature, then its viscosity index will be better. Pourpoint is freezing up warmth of motor oil, indicating its performance in cold weather.
XL performs better at a moderate temperature of 40 degrees Celsius, having a higher kinematic viscosity, SS stands second in this regard.
When the temperature heats to a hundred degrees Celsius, the XL is first in line with a slightly higher kinematic viscosity than SS, having a higher viscosity index. SS stood second in the comparison as both its kinematic thickness and the viscosity index are lower.
In chilly weather, both these oils work similarly with an equal pourpoint (freezing) temperatures.
| Oils (5W-30 Viscosity) | Kinematic Viscosity at 40 oC (cSt) | Kinematic Viscosity at 100 oC (cSt) | Viscosity index | Pourpoint (Degrees C) |
| Amsoil XL | 62.9 | 11.1 | 169 | -50 |
| Amsoil SS | 59.7 | 10.3 | 162 | -50 |
Oil Change Rate of recurrence Comparison
Acids are produced while combustion takes place inside the engine. That’s why the oil contains alkaline additives to neutralize these acids formed. Total Base Number shows the total amount of these base extracts accessible in oil. A greater TBN ensures a retentive oil exchange interval and vice versa.
XL has a lower TBN, allowing it to be use up for a lesser number of kilometers i.e.,19000 Kms.
SS has relatively a higher TBN, making it a better oil in terms of oil alter regularity, having an oil change interval of 24000 Kms.
| Oils (5W-30 Viscosity) | TBN (mg KOH / g) |
| Amsoil XL | 10 |
| Amsoil SS | 12.5 |
Cost Comparison
XL is a cheaper oil with a value card of only 11 US dollars for a liter. However, SS costs 14 US dollars per liter. Amsoil SS is significantly higher priced due to its better performance compared to its colleague. (Prices may vary with time)
Quick Summary
- Both these oils are entirely synthetic and made for gas engines.
- The converter operation of the SS is superior owing to the smaller quantity of ZDDP.
- The sludge lessening ability of the SS is higher than that of XL.
- Anti-wear additives are available higher in SS.
- XL has higher oil volatility compared to SS.
- At medium temperature, XL performs better due to a higher kinematic viscosity and viscosity index compared to SS.
- During winter, both oils perform equally good.
- SS has a higher oil change rate.
