Engine Oil Types
There are basically three main engine oil types on the market: Mineral, Semi-Synthetic, and Fully Synthetic oils. Each has its own unique characteristics, advantages, and usage areas.
Mineral Engine Oils
Mineral engine oils are traditional oils obtained from the refining of crude petroleum. They are generally more affordable because they are less processed. They may be suitable especially for older model vehicles and less demanding driving conditions. However, they may be insufficient in meeting the high performance and protection needs of modern engines. The main advantage of mineral engine oil is its cost, while its disadvantage is that its low temperature performance and high temperature resistance are weaker compared to synthetic oils. Mineral oils tend to evaporate faster at high temperatures and can leave more deposits. This can lead to buildup inside the engine, reducing engine efficiency and accelerating wear.
Semi-Synthetic Engine Oils
Semi-synthetic engine oils are a blend of mineral and synthetic oils. This blend combines the affordability of mineral oils with some performance advantages of synthetic oils. They offer a good balance for middle-aged vehicles and daily driving conditions. Semi-synthetic engine oil is ideal for those seeking a middle ground in terms of both cost and performance. It offers better wear protection and temperature resistance while being more economical than fully synthetic oils. Semi-synthetic oils are a good option especially for vehicles with modern engine technology but not requiring fully synthetic oil. They can offer longer oil change intervals but are not as long-lasting as fully synthetic oils.
Fully Synthetic Engine Oils
Fully synthetic engine oils are produced through chemical synthesis and offer the highest level of performance. Their molecular structures are more regular and pure, which gives them superior properties. They are ideal for modern, high-performance, turbocharged, or diesel particulate filter (DPF) equipped vehicles. The benefits of synthetic engine oil include superior wear protection, excellent performance at high and low temperatures, longer oil change intervals, and contribution to fuel economy. Although their initial costs are higher, they provide significant advantages in terms of engine health and performance in the long run. Synthetic oils protect the engine best especially in extreme hot or cold operating conditions, in high-revving engines, and during long journeys. Additionally, they help keep the engine clean by minimizing deposit and sludge formation inside the engine.
Engine Oil Selection Criteria
Proper engine oil selection is critically important for your vehicle's engine health and performance. Wrong oil selection can lead to engine wear, performance decline, and even serious failures. Here are the basic criteria you should consider:
Viscosity (Fluidity)
Engine oil viscosity refers to the oil's resistance to flow at different temperatures. Viscosity grades determined by SAE (Society of Automotive Engineers) (e.g., 5W-30, 10W-40) provide us with information on this subject. The first number (e.g., 5W) indicates the oil's fluidity in cold weather (W = Winter), and the second number (e.g., 30) indicates the oil's fluidity at the engine's operating temperature. You must comply with the viscosity values specified in your vehicle's owner's manual. Proper viscosity provides rapid lubrication during engine startup and adequate protection at operating temperature. Low viscosity oils (e.g., 0W-20) contribute to fuel economy especially in new generation engines, while high viscosity oils (e.g., 15W-40) can provide better protection in older and worn engines. However, always following the manufacturer's recommendations is the best approach.
Performance Levels and Standards
Engine oils are classified according to specific performance standards. These standards indicate how well the oil protects the engine against wear, corrosion, and deposit formation.
- API (American Petroleum Institute) Standards: Typically starts with the letter 'S' (for gasoline engines) or 'C' (for diesel engines) followed by another letter (e.g., SN, SP). As the letter sequence advances alphabetically, the oil's performance level increases. For example, API SN is newer and higher performing than API SM. These standards determine the oil's properties such as oxidation resistance, deposit control, and wear protection.
- ACEA (European Automobile Manufacturers' Association) Standards: These are standards established by European vehicle manufacturers (e.g., A3/B4, C3). These standards are particularly important for European origin vehicles and indicate suitability for specific engine technologies (e.g., DPF-equipped diesel engines). ACEA C series oils have low sulfated ash, phosphorus, and sulfur (Low SAPS) content to protect exhaust emission systems such as diesel particulate filters (DPF) and catalytic converters.
- Manufacturer Approvals (OEM Approvals): Many vehicle manufacturers (e.g., Mercedes-Benz 229.5, BMW Longlife-04, Volkswagen 504 00/507 00, Ford WSS-M2C913-D) publish special oil specifications and approvals for their own engines. These approvals indicate that the oil has been tested in a specific engine type and meets the manufacturer's performance requirements. Preferring oils with manufacturer approvals specified in your vehicle's owner's manual provides the best protection for your engine. These approvals also generally indicate that the oil meets the engine's warranty conditions.
Vehicle Type and Age
Your vehicle's type and age are also important factors in engine oil selection. Modern engines generally require fully synthetic oils due to tighter tolerances and advanced technologies, while older engines may work better with mineral or semi-synthetic oils. Diesel engines require oils containing different additives, while turbocharged engines need oils resistant to high temperatures. Oils specially formulated for high-mileage vehicles are designed to protect the engine's worn parts and reduce oil leaks.
Driving Conditions
The conditions under which you use your vehicle can also affect oil selection. Heavy city traffic, frequent stop-and-go driving, heavy load carrying, or extreme hot/cold climate conditions can cause engine oil to deteriorate faster. In such demanding conditions, choosing a higher performance and durable synthetic engine oil will better protect your engine. For example, in vehicles that frequently make short-distance trips, the oil may experience moisture and fuel accumulation because it cannot reach operating temperature. In this case, more frequent oil changes or using synthetic oil may be beneficial.
Engine Oil Change Intervals
Engine oil change is one of the most basic and important steps of engine maintenance. Over time and with use, engine oil becomes dirty, its viscosity deteriorates, and it loses its protective properties. This causes increased friction between engine parts, leading to wear and shortening of the engine's life.
Why is Regular Change Important?
- Wear Protection: New oil creates a strong film layer between engine parts, reducing friction and wear. This extends the life of the engine's moving parts.
- Cleanliness: Oil keeps the engine interior clean by suspending deposits, soot, and other contaminants formed inside the engine. Contaminants are collected in the oil filter and expelled from the engine during oil changes.
- Cooling: Oil prevents engine overheating by removing heat from the engine's moving parts. This feature is vitally important especially in high-performance engines.
- Fuel Economy: Clean oil with the correct viscosity ensures the engine operates more efficiently, contributing to fuel economy. Dirty or deteriorated oil can cause the engine to expend more energy.
- Corrosion Protection: Engine oils contain additives that protect metal surfaces inside the engine against corrosion. Regular changes ensure the continuity of these protective properties.
Manufacturer Recommendations and Driving Conditions
Engine oil change intervals should be made according to the mileage or time intervals (e.g., 10,000 km or 1 year) determined by the vehicle manufacturer. However, driving conditions can affect these intervals. Under demanding conditions such as heavy city use, short-distance trips, dusty roads, or extreme hot/cold climates, it may be necessary to shorten the oil change interval. It is best to carefully read your vehicle's owner's manual and follow your authorized service's recommendations. Some modern vehicles have oil life monitoring systems that monitor the oil's condition and notify the driver of the change time. These systems can dynamically adjust the oil change interval according to driving conditions.
Engine Oil Additives: Are They Necessary?
Engine oil additives are chemical substances added to oil to enhance the oil's performance or solve specific problems. There are many different engine oil additives on the market. However, since modern engine oils already contain a wide additive package, additional additives are not needed in most cases. Wrong or low-quality additives can disrupt the oil's balance and damage the engine. Therefore, it is important to definitely consult an expert or check manufacturer recommendations before using additional additives. In some cases, especially in older engines or to solve specific problems (e.g., oil burning, leakage), special additives may be beneficial. However, even in such cases, caution should be exercised and the product's compatibility with engine oil should be checked.
Frequently Asked Questions (FAQ)
1. Can I mix different brands of engine oils?
Mixing different brands and types of engine oils is generally not recommended. Each oil has its own unique additive package, and incompatibility between these additives can reduce the oil's performance or damage the engine. In emergencies, adding a small amount of different oil with the same viscosity and performance level may be possible, but a complete oil change should be made as soon as possible.
2. Why is engine oil color important?
New engine oil is typically light amber colored. The oil's color darkens with use. This is an indication that the oil is cleaning contaminants inside the engine and doing its job. However, the oil being excessively black and thick may indicate that it's time for an oil change or that there is serious contamination inside the engine. Oil color alone is not sufficient to determine the oil's condition; oil level and viscosity should also be checked.
3. When should the oil filter be changed?
The oil filter should be changed together with the engine oil or every second oil change. A dirty oil filter can prevent oil from circulating properly inside the engine and cause engine wear. Following manufacturer recommendations is best.
4. How do I check my vehicle's engine oil level?
Engine oil level should be checked when the vehicle is on level ground and the engine is cold (or after waiting at least 10-15 minutes). Pull out the dipstick, clean it, reinsert it, and pull it out again. The oil level should be between the minimum and maximum marks on the dipstick. If low, add appropriate oil.
Conclusion
Engine oil change and proper engine oil selection are essential for keeping your vehicle's engine long-lasting, healthy, and high-performing. Understanding engine oil types (mineral, semi-synthetic, fully synthetic), paying attention to criteria such as viscosity, performance standards, and manufacturer approvals will help you find the most suitable oil for your engine. Remember, your engine's owner's manual is always the most reliable source. With regular maintenance and proper oil selection, you can enjoy your vehicle for many years.