Is Synthetic Oil the Same as Full Synthetic Oil?

[Dallas]

Synthetic oil is not the same as full synthetic oil. Synthetic oil is divided into semi-synthetic oil and full synthetic oil. Strictly speaking, full synthetic oil refers to high-quality oil products made 100% from polyolefins or artificially synthesized esters, usually labeled with the word "synthetic" on the oil container. Semi-synthetic oil is made from semi-synthetic base oil, which is lubricant formulated from Group III base oils internationally. It is a product purified from mineral oil through hydrocracking technology. Compared to semi-synthetic oil, full synthetic oil has the following characteristics: 1. Better high and low-temperature performance; 2. Longer oil change intervals; 3. Suitable for more severe driving conditions.

[DelSerenity]

After researching extensively, I found that synthetic oil is not entirely equivalent to full synthetic. There are actually three types of synthetic oils on the market: mineral oil with additives is called semi-synthetic, those made with Group III base oils are considered conventional synthetic oils, and only those using Group IV PAO or Group V ester base oils are true full synthetics. Full synthetic oils have more stable molecular structures, better low-temperature fluidity, stronger high-temperature resistance to degradation, and can extend oil change intervals to over 10,000 kilometers. However, some manufacturers play word games by labeling Group III base oils as 'synthetic,' when their performance is significantly inferior. When choosing engine oil, you should look for the API certification grade on the container – for example, SP-grade is certainly more reliable than SN-grade. Full synthetics are expensive for good reason, especially for turbocharged vehicles which perform best with this type of oil.

[AdrianLynn]

After repairing cars for over a decade, I must remind you that there's a lot to synthetic engine oils. True full synthetic must use PAO or ester base oils with higher anti-wear additive content and lower evaporation loss rates. Conventional synthetic oils actually use Group III hydrocracked mineral oils, which perform significantly worse. The simplest way to tell them apart: check the price and specifications. Full synthetics typically retail above 200 yuan per can, maintain more stable 100°C kinematic viscosity, and have high-temperature shear values exceeding 3.5 mPa·s. I've seen car owners buy cheap oils labeled 'synthetic technology' only to experience severe performance degradation after 5,000 km with increased engine noise. Nowadays, oil cans have fine print on the back - remember to look for 'Full Synthetic' to get the real deal.

[LeEvan]

Experience from changing engine oil over twenty times: Synthetic doesn't equal full synthetic. Full synthetic uses man-made base oils, with performance closest to racing oil. Conventional synthetic oil is essentially refined mineral oil with synthetic additives. The key differences are two points: True full synthetic has a pour point reaching -40°C, enabling smoother cold starts; and its CCS low-temperature viscosity value is lower, making winter starts effortless. Last time I switched my old Toyota to genuine full synthetic, fuel consumption dropped by 0.5L and the engine noise became quieter. Remember not to be fooled by product names—the certification marks on the bottle are the most reliable indicators.

[VonJames]

A friend who works in vehicle maintenance told me that there are actually standards for engine oil classification. API divides base oils into five categories: Groups I and II are mineral oils, Group III is considered synthetic technology oil, and only Groups IV and V are fully synthetic. Some brands now label Group III base oils as 'fully synthetic,' which is actually non-compliant, and the real anti-wear performance is more than 30% worse. I've compared test data: true fully synthetic oils have better anti-carbon buildup capability, higher HTHS values, and can last 3,000 kilometers longer before needing replacement. When choosing oil, don’t just look at the marketing terms—check the ACEA certification level on the bottom of the bottle. C3/C5 standards are much more reliable. Cars with GPFs especially need fully synthetic oil, otherwise, the particulate filter can easily get clogged.