Auto Engine Oil: Which Is Right For My Car?

Have you tried shopping for engine oil/motor oil lately? There are literally whole aisles dedicated to the stuff at the local auto parts store. There was conventional engine oil and a bunch of synthetic oil formulas with a never-ending variety of chemical additives to choose from. How does a person make the correct selection when it’s time for an oil change? Whether you drive an old clunker or a brand-new hybrid, let’s dive into some engine oil facts to get you the right oil for your needs.

What Engine Oil Does

I’m sure you have heard engine oil referred to as the lifeblood of the internal combustion engine. The truth is that it’s a crucial component for the longevity and performance of your vehicle. With the addition of various chemical additives, this oil performs many vital tasks. For example, it:

• Absorbs heat
• Breaks down existing sludge residue
• Condition seals and gaskets
• Inhibits corrosion, rust, and oxidation
• Lubricates engine components
• Neutralizes acids
• Prevents new sludge buildup
• Reduces wear on engine components

What Determines Oil Types?

In general, motor oil has two elements: base oil and chemical additives. Refining crude oil removes impurities like sulfur, solid particulates, and waxy substances, producing a base oil. Refining techniques determine the base oil’s properties, characteristics, and behavior. Determining the oil grade and type depends on the amount of impurities left in the base oil after refining. Those impurities affect the viscosity, friction control, and how the oil reacts to temperatures. Always follow the manufacturer’s recommendations found in your owner’s manual when choosing an engine oil type for your vehicle.

Conventional Engine Oil (Mineral)

Initially, all engine oils used in combustion engines were conventional type oils (mineral oil). Conventional oils are usually the most inexpensive option since they require less rigorous refinement procedures. The cleaned and distilled crude oil (without substantial molecular changes to the hydrocarbons) produces a high-quality base oil. Many domestic auto manufacturers recommend using conventional oil for vehicles manufactured through the mid-1990s. 

Conventional Oil Change Intervals

Expect to change your conventional oil every 3,000 – 5,000 miles.

Full Synthetic Engine Oil

Full synthetic oil requires more refining, which actually changes the base oil’s molecular structure. The molecules in full synthetic oil are more uniformly shaped, with fewer impurities. Full synthetic oils offer benefits like extended oil change intervals and improved performance for high engine temperatures. It’s important to note that every oil change service must replace the old oil with the specific, full synthetic oil indicated in your owner’s manual. Using a different type of oil may void your manufacturer’s warranty. 

Full Synthetic Oil Change Intervals

Expect to change your full synthetic oil every 10,000 – 20,000 miles.

Synthetic-Blend Engine Oil

Synthetic-blend oil balances the economy of conventional oil with the exceptional performance of full synthetic oil. Check with your auto service center to see if synthetic-blend oil suits your vehicle.

Synthetic-Blend Oil Change Intervals

On average, expect to change your synthetic-blend oil every 7,500 miles.

Hybrid Engine Oil

Engine oils formulated for hybrids prioritize performance and protection when dealing with the specific needs of hybrid vehicles. Rapid acceleration, stop-and-start driving conditions, plus cooler engine temperatures require specially formulated hybrid motor oils. Always use the motor oil rated for your specific hybrid vehicle and follow the manufacturer’s oil change intervals.

High-Milage Engine Oil

High-mileage oil is a unique type with a special mixture of additives that maintains its viscosity, helps protect engine seals, and keeps oil from evaporating. This extra protection is crucial for vehicles with high mileage because oil burn-off becomes more of a concern, leading to more engine wear. High-mileage engine oils also have seal conditioners to help protect the gaskets and bearing seals. This is especially beneficial in older cars since it works to prevent oil leaks and restore the compression in the engine combustion chamber. 

Engine Oil Chemical Additives

All engine oils contain chemical additives to help the base oil reduce friction, absorb heat, slow corrosion, and prevent sludge from forming. Engineers rigorously test engine oils to determine which additives work best for each type and formula. They typically contain a proprietary chemical additive blend that can make up 10% to 30% of the oil’s ingredients. The remaining percentage is conventional, synthetic-blend, or all synthetic base oil. Here’s a short list of common chemical additives and what they do:

• Anti-foaming: When engine oil forms bubbles, it cannot coat and protect the critical engine components or keep them cool. This may cause critical damage to your engine, especially under high temperatures. Anti-foaming chemical additives prevent air from compressing in the oil and forming foam – even if there is too much oil in the system due to overfilling. Engine oil must also act as hydraulic fluid when engaged with variable camshaft timing, which foaming oil cannot do. 
• Anti-wear agents: Anti-wear agents form a protective layer on engine parts sensitive to high operating temperatures, like cylinder walls, piston rings, lifters, and cams. They reduce friction caused by repetitive metal-to-metal contact and act as antioxidants. They get used up over time. 
• Antioxidants: Under high temperatures, motor oil can oxidize when mixed with oxygen. When that happens, the oil breaks down, thickens, and forms sludge. Antioxidants slow down oxidation and the formation of deposits. They also help keep the engine clean and prolong engine oil life. 
• Detergents: As the name suggests, detergent additives help clean and prevent the formation of deposits, rust, and corrosion. They get used up over time. 
• Dispersants: These chemical additives absorb and hold solid particulates within the oil. They delay sludge, acids, and varnish formation from damaging the engine. However, they lose effectiveness as engine oil ages.
• Friction modifiers: Graphite and molybdenum act as friction modifiers, helping reduce friction when your vehicle’s engine operates under high temperatures and heavy loads. They lose their effectiveness as engine oil ages. 
• Pour-point depressants: These chemical additives prevent the hardening of wax particles in the engine oil under cold conditions. As a result, the oil flows freely at low temperatures and does not require the vehicle’s engine to work harder.
• Rust and corrosion inhibitors: The engine’s internal parts can rust and corrode from exposure to moisture and acids. These inhibitors coat the parts and protect them from these hazards. 

Oil Change Service in San Diego, CA

Wentworth Automotive‘s ASE-certified technicians only use factory-recommended, high-quality conventional engine oil, oil blend, or full synthetic oil, and filters for all oil changes. Your safety depends on your vehicle’s mechanical condition. That’s why we make it our #1 priority to provide exceptional service, and we guarantee you’ll be satisfied with your oil change in San Diego.

Schedule Oil Change Reservation

Call our office staff at (858) 541-1044 or visit our website to make your oil change reservation.