Base Oil Types and Variations
We’ve often heard the terms “Mineral, Semi Synthetic and Fully Synthetic” when it comes to engine oil, but what do they mean and why are these Base Oils important? In this blog story we’ll go through the basics and introduce a lesser known but much more relevant category – Hydrocracked Oil.
As we should mostly know, the job of engine oil is to not only lubricate the moving parts in a motor but also cool and clean those parts, preventing direct friction and allowing the engine to operate smoothly and quietly. Over time, engine technology has advanced and as a result, Motor Oil technology has also advanced. It’s just hard to see when oil from 30 years ago was a brown liquid we poured in to the engine, these days the most advanced engine oil is still exactly that – a brown liquid we pour in the engine!
Mineral Oil – A mineral base oil is the most basic form of Engine oil. It is made in the refinery after being distilled from Crude Oil and due to the basic nature, its Technical properties are limited, meaning it is more suited to older style engines using more traditional materials and lower stressed components. As a finished product, the Mineral Oil is 80-85% Base oil with 15-20% Additives to define viscosity and emissions compliance. The most common viscosity would be 15W-40 or 20W-50.
Synthetic Oil – Is this completely man made? Not really but it is very close. In order to make a Synthetic oil the refinery still starts with Crude oil, however, once the crude is distilled and petroleum is separated, this is then used to start the synthetic oil process. The Straight Run petrol is chemically dissected or “cracked” and the molecules are rearranged in specific ways to produce a Synthetic Base Oil. The finished product is then a combination of Synthetic Base Oil and also various Additive Packages to produce the required Engine Oil. Due to these extra processes a Synthetic oil can be tailored to almost any viscosity range including 0W-30, 0W-40 and 10W-60. Depending on engine design and use, a Synthetic product can be much more resistant to wear in comparison to Mineral or Semi Synthetic base oils. These factors also result in a much more expensive product to produce and this can be prohibitive for Vehicle Manufacturers when considering service costs and availability.
Hydrocracked Oil – Here is the (relatively) new kid on the block. Many people have previously dismissed Hydrocracked oil as a type of Semi Synthetic product while this is very much an oversimplification. Where a semi synthetic end product still has Mineral Oil as its base, the Hydrocracked product becomes a new separate category. This type of base stock is much more similar to Synthetic in that the crude oil goes through many extra steps of refinement and “cracking” compared to Mineral. While not as lengthy as the fully synthetic base there is still lots of room for manipulation allowing more flexibility in Viscosity and specific design. This results in a more cost effective yet very advanced type of engine oil that is now favoured by Vehicle Manufacturers when they are considering giving their seal of approval to an oil company.
So how do we choose which is correct for our own application? Is one better than the other? This is probably one of the most contested points when it comes to engine oil and there is no one answer for all vehicles. While it would seem that a Fully Synthetic product would be the best for everyone you have to remember the specific product may not be designed for your engine requirements, generally this type will be better for racing or very high performance applications. While Mineral oils are generally not suitable for late model modern engines due to their high performance nature, the mineral product will be perfectly suitable for an engine designed when that is the only type of oil available. Due to the wide range of engine types, emissions standards and viscosity ratings it comes to show that Hydrocracked oils are the industry standard for being reasonably priced and easily tailored to suit.
What if my vehicle is under warranty but I choose to have it serviced by a specialist mechanic? Can the wrong base oil void my warranty? Not necessarily, no, as long as the product carries a Manufacturer Approval. Vehicle Manufacturers will generally only give an “in-warranty” approval to an oil manufacturer if the product is Fully Synthetic OR Hydrocracked. This is because during the engineering and development process of an engine the manufacturer will want a suitable product that is not only going to provide peak performance and protection but also remain cost effective and accessible for the service life of the vehicle. With longer service intervals and precise engine technology it is highly unlikely an approved oil will use Mineral or Semi-Synth base stock.
Ultimately Liqui Moly have all of the bases covered when it comes to the right product for the right vehicle – Just as the Manufacturer Intended.
Article prepared by Liqui Moly Australia