What is the highest grade of engine oil?
3 Answers
Details are as follows: 1. API Quality Grade: The API quality grade naturally distinguishes the quality of engine oil. There are more than ten grades for gasoline engine oils, ranging from SA to SN, while diesel engine oils have grades such as CA, CB, etc. For any type of engine, the larger the letter following the initial "S" or "C," the higher the quality of the oil, the better its performance, especially in terms of fuel economy. Of course, the price will also be higher. Generally speaking, the further back the letter is in the alphabet, the better the API quality grade. For example, the best grade for gasoline engine oil is SN. 2. SAE Viscosity Grade: The SAE viscosity grade is more complex. Two-stroke engine oils have two grades, SAE20 and SAE30, with SAE30 being the most commonly used. However, cars generally use four-stroke engine oils, such as 5W30. Here, "W" stands for winter. The smaller the number before the "W," the lower the minimum temperature the oil can withstand. Conversely, the larger the number after the "W," the higher the maximum temperature the oil can handle.
From a professional perspective, the current API SP standard represents the highest tier of engine oil classification, offering top-tier protection for modern engines—particularly in preventing low-speed pre-ignition (LSPI), which is especially beneficial for turbocharged vehicles. SP-rated oils enhance fuel efficiency, reduce emissions, and can extend engine lifespan by tens of thousands of kilometers. When selecting oil, don't just focus on the rating; ensure it matches the correct viscosity (e.g., 0W-20) and prioritize full synthetic formulations for extreme temperature performance. Regular changes every 7,500 km or six months maintain optimal engine operation. Premium brands like Mobil 1 SP-grade offer excellent value, while avoiding lesser-known manufacturers safeguards your vehicle. Though details matter, remember SP is the gold standard—using it delivers both peace of mind and cost savings.
As a regular car owner who has been driving an SUV for several years, I've gained deep insights: the highest oil grade is API SP. I remember during my last oil change, the repair shop recommended SP-grade oil, and I noticed the car accelerated more smoothly with reduced engine noise. The SP standard ensures superior wear protection, extending component lifespan. In my routine maintenance, I check the dipstick to ensure proper oil levels and change the oil every 5,000 kilometers. Choosing the right viscosity like 5W-30 as specified in the owner's manual is crucial. These small habits boost driving confidence – never compromise with lower-grade oil to save money, as premium oil pays off in long-term fuel efficiency and safety. Simply put, SP is the industry benchmark – choosing it is always the right decision.
