Automotive Oils: Dexos, SAE, and Other Standards

The reliability and longevity of the vehicle depends on a properly selected engine oil. The right oil for the vehicle not only prevents friction and wear of engine parts, but also protects it from overheating and contamination. To make the right choice, it is necessary to be properly oriented in their many standards and specifications.

What is Dexos Oil?

Dexos is a set of engine oil standards, including Dexos1 and Dexos2, each designed for different engine types and operating conditions. Developed by General Motors (GM) for its vehicles.

Dexos specifications include strict chemical composition and performance requirements to ensure its superior properties:

  • excellent oxidation resistance;
  • low vaporability;
  • high viscosity stability;
  • improved wear protection.

These characteristics make it ideal for use in today's high-performance engines that operate at elevated temperatures and loads.

The advantages of using Dexos are due to:

  1. providing superior engine wear protection.
  2. Improved fuel efficiency. 
  3. Reduced deposits in the engine and exhaust system.
  4. Improved performance at extreme temperatures.

The use of Dexos oils is recommended for all modern GM vehicles because it helps maintain optimal engine performance, improves engine reliability and efficiency, and meets the manufacturer's warranty requirements.

What I SAE Oil?

SAE (Society of Automotive Engineers) is a motor oil classified according to a system developed by the Society of Automotive Engineers (SAE). This classification determines the viscosity of the product and its behavior at different temperatures, which allows you to choose the right brand for your specific operating conditions.

SAE classification

SAE classification of oils is based on their viscosity, which is measured at various temperature conditions. The SAE designation uses numbers and letters that indicate viscosity characteristics. For example, in the SAE 5W-30 designation:

  • SAE: denotes the standard set by the Society of Automotive Engineers.
  • 5W: the number before the letter "W" (Winter) indicates the viscosity of the product at low temperatures. The lower the number, the better the oil behaves on cold starts.
  • 30: the number after the "W" indicates the viscosity at engine operating temperature. The higher the number, the more viscous the oil is at high temperatures.

For example

  • SAE 5W-30: indicates a low viscosity that is low at cold temperatures, providing easy cold weather engine starting and maintaining optimum viscosity at operating temperatures.
  • SAE 10W-40: viscosity is slightly thicker at cold temperatures compared to 5W-30, but provides better protection at high temperatures.

The choice of the appropriate SAE oil depends on climatic conditions and the requirements of the vehicle:

  • in cold climates, it is better to use oils with a lower number before the "W" (e.g. 0W or 5W) to ensure easy starting of the engine;
  • in hot climates, an oil with a higher number after the "W" (e.g., 40 or 50) is recommended to provide protection at high temperatures;
  • when driving in harsh conditions (in the mountains or towing), choose an oil with a higher viscosity at operating temperatures (e.g., 10W-40) to provide additional engine protection.

Understanding all the nuances of SAE classification and following the manufacturer's recommendations will help you make the right choice of oil for your vehicle and ensure reliable operation of its engine in various conditions.

Understanding API Oils

API is the American Petroleum Institute, which has developed a classification system based on the quality and performance of motor oils. This division into classes helps to choose a product that meets modern engine requirements and ensures reliable performance.

Oils with API classification are divided into two main classes:

  1. Category S class - service oils for gasoline-powered engines
  • API SN: provides improved protection against deposit formation at high temperatures, reduces wear and improves fuel economy.
  • API SM: a standard introduced before SN, has the same characteristics but less stringent requirements than SN.
  • API SL and older: used for engines manufactured before certain years and have less stringent quality standards.
  1. Category C class - for diesel engines
  • API CK-4: provides high protection against wear, corrosion and deposit formation, designed for modern, low-emission engines.
  • API CJ-4: has similar characteristics but less stringent requirements than CK-4.
  • API CI-4 and older: has less stringent quality standards and can be used for older diesel engine models.

American Petroleum Institute (API) certification plays an important role in choosing an engine oil because it provides:

  • better engine wear protection;
  • reduced fuel consumption;
  • extended engine life;
  • compliance with environmental requirements.

Using an API certified oil is a guarantee that the "heart" of your vehicle is getting the best possible protection and performance.

The Importance of ACEA Oils for European Cars

ACEA (Association des Constructors Europeans automobiles) is an association of European automobile manufacturers that sets quality standards for motor oils.

These standards are designed specifically for European cars and take into account their special requirements.

ACEA classifications

ACEA oils are classified by two letters:

  • First letter: A/B: for gasoline and diesel engines with catalytic converters and particulate filters; C: for catalytic diesel engines with particulate filters; E: for commercial vehicles.
  • Second letter: indicates the level of performance. The further the letter in the alphabet, the higher the performance of the oil.

For example:

  • ACEA A3/B4: designed for gasoline and diesel engines with catalytic converters and particulate filters, and complies with the latest standards.
  • ACEA E4: designed for commercial vehicles and conforms to older ACEA standards.

These classifications help to select oils that meet the stringent requirements of modern European engines.

Why are ACEA oils important for European cars?

  • European cars have stricter emission requirements than cars in other countries. They are therefore equipped with additional after treatment systems and catalytic converters.
  • ACEA oils are specifically designed to meet these requirements and protect the environment.

The use of ACEA classified oils is essential to keep European vehicles running optimally, ensuring their longevity and meeting stringent environmental requirements.

OEM-Specific Oils and Their Benefits

OEM oils are specially formulated and certified for use in specific vehicle models. They meet the manufacturer's strict requirements to ensure optimal and efficient engine performance.


Volkswagen has developed several oil specifications for its vehicles

  • VW 504.00/507.00: Designed for most modern VW gasoline and diesel engines, including those with diesel particulate filters (DPF). Provide excellent wear protection, high thermal stability and low exhaust emissions.
  • VW 502.00/505.00: used in older VW models. Provide high wear protection and excellent detergent properties, important for high mileage engines.

Mercedes-Benz has its own oil specifications, known as MB Approval

  • MB 229.5: designed for modern gasoline and diesel engines. Provide high wear protection, improved fuel economy and long drain intervals.
  • MB 229.51: this specification is for engines with exhaust after treatment systems. It provides protection for both the engine and after treatment system.

BMW also has its own specifications labeled as BMW Longlife

  • BMW Longlife-01: designed for most modern BMW brand gasoline and diesel engines. Longlife-01 oils are characterized by high thermal stability, wear protection and long drain intervals.
  • BMW Longlife-04: designed for engines with exhaust after treatment systems. Protects both the engine and the after-treatment system.

The benefits of using OEM oils are based on:

  • better engine protection from wear and corrosion;
  • reduced fuel consumption due to improved engine lubrication;
  • extending engine life by protecting the engine from damage;
  • maintaining the performance of emission control systems.

Using OEM oil can help preserve your vehicle's warranty.

Why Proper Oil Choice Matters for Your Vehicle

Choosing the right engine oil for your vehicle is of the utmost importance.

  1. The right oil provides the necessary lubrication and protection to the moving parts of the engine, which helps it run smoothly and efficiently.
  2. Protects against wear, rust and corrosion.
  3. Reduces fuel consumption.
  4. Keeps emission control systems working properly.
  5. Extends engine life.

It should be remembered that extending the life of the engine depends not only on the use of the appropriate engine oil, but also on its regular replacement. Because over time, it loses its protective qualities.

Not all oils are the same. It is important to choose the right oil for your particular vehicle, taking into account factors such as engine type, climate and operating conditions. Lube Squad offers a wide range of high-quality oils, including Dexos, SAE, API, ACEA, and OEM-specific oils.

Use the Lube Squad catalog to find the right oil for your vehicle.