Are All Groups Of Synthetic Motor Oils The Same? Groups III Vs IV Vs V
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Are All Groups Of Synthetic Motor Oils The Same?
The simple answer:
Are All Groups Of Synthetic Motor Oils The Same? Groups III Vs IV Vs V
No. In fact, there are big differences in how well each base oil group does its job. In general, Group IV base oils work the best, Group III the next best, and so on in the opposite order. But know that there are some exceptions. And you can’t just look at the type of base oil to decide how well a motor oil works.
You have to think about the whole thing, including the additives.
Here’s the full answer to are synthetic motor oils the same:
To make it easier for you to study the subject, we’ve broken it down into common questions:
- What are the different base oil groups?
- Are the API group classifications progressively better?
- Are Group III base oils “synthetic?”
- Are synthetic base oils magic?
What are the different base oil groups?
The classification system is made up of five groups, from Group I to Group V:
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• Group I Base Oil Characteristics
The least refined base oils are those in Group I. Most of the time, they are a mix of different hydrocarbon chains that are not very uniform. Even though these oils are used in some auto oils, they are usually used in less demanding ways.
• Group II base oil Characteristics
Mineral-based motor oils often use base oils from Group II. In terms of volatility, oxidation stability, resistance to wear, and flash/fire point, they do okay to well. When it comes to things like pour point and cold-crank viscosity, they only do okay.
• Group III base oil Characteristics
Group III base oils are made up of reconstructed molecules that work better in a wide range of areas and have good uniformity and stability at the molecular level. Synthesized materials can be used by manufacturers to make synthetic and semi-synthetic lubricants.
• Group IV Base oil Characteristics
Polyalphaolefins (PAO), which are chemically made base oils, are used to make base oils in Group IV. PAOs are very stable, have uniform molecules, and improve performance.
• Group V Base oil Characteristics
Group V base oils are also made with chemicals, but they don’t fit into any of the other groups. Esters, polyglycols, and silicone are all examples of oils that belong to Group V. Like Group IV oils, Group V oils tend to work better than Groups I–III oils. One example of a mineral-based Group V exception is white oil, which is a very pure lubricant used in many different industries, from making cosmetics to making food.
Are the API group classifications progressively better?
In other words, is motor oil made from base oils in Group III better than motor oil made from base oils in Group II, and so on?
In general, yes. Unlike food, which usually gets less healthy the more it’s processed, base oils get better the more they’re refined and processed.
But there are exceptions that break that general rule.
Some Group III motor oils can do a better job than some Group IV motor oils. That’s because the way the base oils and additives work together determines how the final product turns out. Like base oils, there are many different kinds of additives. So, a Group III oil with top-notch anti-wear, anti-oxidant, and other additives could perform better than a Group IV motor oil, even though Group IV base oils have more obvious benefits. The point is that you can’t judge a motor oil just by its base oils; you have to look at the whole thing.
The last group is Group V, which is a kind of catch-all for anything that doesn’t fit in the first four. In fact, some Group V oils are not at all good for use in cars.
Are Group III base oils “synthetic?”
Yes, at least in most countries.
It has been hard to agree on what the term “synthetic oil” really means, but most people agree that it refers to lubricants that have been made with a high level of performance in mind. Most countries call synthetic oils Group III base oils with very high viscosity indices.
In the past, most people thought that the only real “synthetics” were Group IV base oils made from PAOs.
That changed because of a well-known lawsuit between Mobil and Castrol. Mobil said that Castrol was misleadingly marketing its Syntec motor oil as a synthetic oil, even though it wasn’t made from PAO base oils. Mobil’s claim was based on tests done by a third-party lab, which showed that samples of Syntec it got as early as December 1997 were made of 100% mineral oil.
The two sides argued, but in a landmark decision in 1999, the National Advertising Division of the Council of Better Business Bureaus said that Castrol Syntec, as it was made at the time, was a “synthetic” motor oil.
Back then, and still now, there was a lot of debate. On the Internet, you can find all kinds of purists who won’t admit that Group III oils are “synthetics.” For them, PAO is the only option.
Don’t get involved in the “my base oil vs. your base oil” cage match. The performance of the oil is more important to your engine than the base oils that go into it. Look for motor oils with claims about how well they work that are backed up by industry-standard testing or results from real-world use. That’s the most important thing.
If you really need to know what base oils are in a formula, you’ll have to do some research because oil companies keep that information secret.
Check out this post for more information: How Much Is My Oil “Synthetic”?
Are synthetic base oils magic?
Ok, that’s not really what people want. But many people have the wrong idea that synthetic base oils are not made from crude oil and that switching to only synthetic lubricants would make us much less reliant on oil from other countries and sources that don’t last forever. If synthetic base oils don’t come from crude oil, what do they come from? Rainbow dust and unicorn horns?
Crude oils are used to make synthetic base oils. But they have been cleaned up a lot more than regular base oils. In the process of making synthetic base oils, sulfur and waxes that are found in regular base oils are taken out by a chemical reaction. This makes a product that works better and is better for your engine.
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