What is the difference between full synthetic and synthetic blend? Motor oil is a crucial element for a functioning engine. Picture your typical combustion engine: several hundred pounds of iron, aluminum, and steel, housing an assortment of cylinders and pistons, subject to thousands of combustions per minute. As the pistol fires through the cylinder repeatedly, the buildup of heat within the engine becomes immense.
Without some form of lubrication – and a lot of specialized engineering tricks – an engine would very quickly break down and weld itself into an unusable block of metal.
Highly specialized motor oil plays a large role in minimizing the otherwise catastrophic levels of friction and heat generated over the many thousands of combustions an engine is designed to handle every time the ignition is turned on. And because there are hundreds of different designs of internal combustion engines across the automobile industry, there are many, many kinds of motor oil.
Like all engines, however, you can break most motor oil down into just a handful of categories: full synthetic, semi-synthetic (or a synthetic blend), and conventional oils. But what is the difference between full synthetic and synthetic blend? Do cars still use conventional oils?
Motor oil does many different things at once. It cleans, it cools, it lubricates, and acts as a seal around the pistol head to help keep those combustion gases inside the combustion chamber, maximizing the efficiency of every drop of fuel.
That’s also why oil changes are so crucial. As your car engine goes through its paces, it continuously recycles its oil. At some point, given enough operating time, engine oil ceases to do its job well due to the accumulation of microscopic soot and metallic particles, which eventually clog the oil filter, and begin to affect the oil’s efficiency, leading to mechanical degradation, loss of viscosity, and loss of alkalinity.
Oil changes ensure that your engine continues to operate optimally, reducing fuel consumption and improving your car’s longevity.
Different Types of Motor Oil
All motor oils must be able to lubricate an engine’s moving parts, filter out unwanted solids to minimize friction, neutralize the acids caused by internal combustion, minimize the buildup of gunk within the engine, and keep engine temperatures within tolerable levels to avoid damage to the metal.
As such, the composition of every type of motor oil is ultimately the same:
- base oils
- proprietary additives (affecting viscosity, filtration, and lubrication)
The base oils in motor oil are usually either petroleum-based chemicals, synthetic polymers called polyolefins, or a combination of both. Conventional oils are wholly petroleum-based, while fully synthetic oils use only synthetic polymers. The difference between full synthetic and synthetic blend oils is that blends utilize both synthetic and mineral base oils.
Because there are many proprietary blends of base oils and additives, all oils are categorized via a grading system developed by the Society of Automotive Engineers (SAE). This grading system tests motor oils based on their mechanical viscosity, weight at working or high temperatures, and low temperature (winter) properties.
If a motor oil is graded with a W, it is considered a winter grade. This means the oil’s properties were tested at low temperatures. Motor oils without a W grade were tested based on their working temperature only. A motor oil can have multiple grades: for example, 5W-30. The lower the number, the better the flow – and the higher the number, the higher the viscosity.
Every modern engine is built with certain oils in mind based on this grading system. While there are still differences between two 5W-30 motor oils from different manufacturers (one might last longer before needing an oil change or lead to slightly better performance in the long-run), both will be fine if your engine matches.
What is Conventional Motor Oil?
Engines existed before the use of mineral oils as lubricants. Instead, these steam engines used a mixture of base petroleum and animal or vegetable fats to keep pistols lubricated. Unfortunately, these mixtures were ineffective at higher temperatures, and often led to a buildup of gunk in and around the engine. As a result, early steam engines were prone to break down or stop working due to corrosion and sludge.
It wasn’t until the discovery of mineral oil bases for motor oil that a lubricant was developed that would still function at higher temperatures.
Conventional motor oil still uses the same mineral base oils, distilled from petroleum. These mineral base oils are categorized based on viscosity, percentage of saturated compounds (which resist reactions), and sulfur content.
Nowadays, few cars still run on purely conventional motor oil. This is because synthetic or semi-synthetic oil blends became the norm in the 1990s, and all modern cars utilize either a mixture of petroleum-based mineral oil bases and synthetic polymers, or an entirely synthetic oil base.
That being said, if you’re driving a vintage model or using an older engine, chances are that it was designed to work with conventional motor oil.
What is Synthetic Motor Oil?
Synthetic motor oils for cars have been around since the 1970s, and solved many problems caused by fluctuating external temperatures, particularly in very cold and very hot regions. Synthetic oils are highly temperature resistant and maintain their viscosity and oxidative stability even in the depths of winter, and in hot, arid climates.
The downside of synthetic motor oil is that it’s more expensive, and as a disposable, yet largely non-renewable resource, synthetic oils take longer to break down and decompose in the environment than conventional mineral base oils.
Synthetic motor oils are often still obtained from petroleum but can also be developed through other raw materials. The exact process differs from producer to producer and is often considered a trade secret. The end goal of every synthetic motor oil is largely the same: to produce a base oil that maintains low reactivity and stable viscosity across a large range of temperatures and working conditions.
Synthetic motor oils aren’t required for conventional internal combustion engines but can improve longevity and efficiency in the long run.
What is a Synthetic Blend Motor Oil?
The difference between full synthetic and synthetic blend oils lies in the ratio of conventional mineral oil to synthetic oil used. Some motor oils blend the benefits of synthetic oils with the lower cost of conventional oils, at a rate of about 30/70 synthetic to conventional.
The result is a motor oil that shares some of the stability and efficiency properties of synthetic oils, at a lower hit to the wallet. As a result, the difference between full synthetic and synthetic blend is largely a matter of cost, with minimal changes in efficiency.
What Motor Oil Do I Need?
It all depends on the engine. For example, a 2021 Ford F-150 has up to 11 different models. Most of its engines are best serviced with 5W-30 graded motor oil.
Full synthetic and synthetic blends are usually recommended, with the difference between full synthetic and synthetic blend oils boiling down to availability and cost.
If you’re not sure how to perform an oil change yourself, it’s always a good idea to call your mechanic. While your car will usually tell you when you need to top up your motor oil or schedule a total oil change with us at Blu Automotive based on your current “oil life”, it’s a good idea to manually test your oil levels with a dip stick from time to time, and schedule a change about once every 5,000 to 7,500 miles, depending on your car’s make and model, how you drive (short vs. long distances), and the type of oil you use.
