Is Synthetic Better than Conventional Motor Oil?

You’ve heard the question, probably at every oil change:  Synthetic or conventional? If you are like most customers, there is about a 70% chance you go for conventional, which we will refer to as mineral oil.  But then you may ask yourself: Is synthetic better? Is there much of a difference? Synthetic is a nice word for imitation, so should imitation cost more? Ewing Buick GMC has some answers.

Motor oil’s three jobs in prioritized order are: lubricating, cooling, and cleaning.  Mineral motor oil begins as crude oil, which, like other petroleum products, is created in a refinery through the processes of separation, conversion, and treatment. Most synthetics also have their origin in distilled crude oil (Pennzoil makes theirs from natural gas) but is then formed in a lab where it is broken down to the molecular level and rebuilt with completely man-made chemical compounds. There are several different kinds of synthetic oils, but most synthetic motor oils are known as polyalphaolefins (PAOs). For this article, “synthetic oil” means PAO. 

When you look at mineral motor oil under a microscope, you’ll see molecules of different shapes, sizes, and structures. With synthetic oil, you will see molecules of nearly identical size and structure. One is a pile of rocks, and the other is a neat stack of golf balls. This tells you something about Synthetic oil’s consistency and purpose-built formation.

Synthetic Oil Advantages

The American Automobile Association conducted a highly respected study comparing synthetic and mineral oil.  They offered this in their conclusion:

“Oil protects critical engine components from damage and AAA found that synthetic engine oils performed an average of 47 percent better than conventional oils in a variety of industry-standard tests,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair. “With its superior resistance to deterioration, AAA’s findings indicate that synthetic oil is particularly beneficial to newer vehicles with turbo-charged engines and for vehicles that frequently drive in stop-and-go traffic, tow heavy loads or operate in extreme hot or cold conditions.”  Here are some of the specific synthetic oil advantages:

• Greater Engine Protection
  Very high heat and heat over time causes mineral oil to break down and lose much of its lubricating ability, hence the need for regular changing. Fully synthetic oils are significantly more resistant to breaking down from both heat and time, thus will protect your engine longer. All things being equal, an engine is more likely to reach very high mileage, such as 200K – 250K miles, with synthetic oil.
• Cleaner Engine
  All mineral oil contains impurities that have a tendency to bond with debris picked up in the cleaning process. Over time this forms deposits in the oil which build up to the point they form a sludge which reduces the oil’s effectiveness. Synthetic oil contains far fewer impurities and almost never forms deposits or sludge. Also, synthetic oil composition enables it to contain a greater amount of additives that have specific engine-cleaning properties.
• More Stable Viscosity
  Mineral oil thins or thickens as temperatures rise or drop respectively. Synthetic oils are significantly better at maintaining their viscosity amidst temperature changes, thus protecting your engine more constantly.
• Longer Lasting
  Because synthetic oil maintains its original integrity longer and stays cleaner than mineral oil, it can go up to twice as long between changes. Some brands tout change intervals as long as 15,000 to 25,000 miles. Buick and GMC maintain an oil change interval of 7,500 to 10,000 miles for most models. If you plan to stretch oil change intervals, be sure to use a high-grade oil filter that can stay effective for the duration. 
• Towing and High Loads
  Slow engine speeds, heavy payloads, towing, and long hills, are all cases where mineral oil films protecting moving parts become extremely thin, resulting in higher wear. The advantage of synthetics and their consistent viscosity is at its most relevant in these situations.
• Turbocharger Protection
  Because they are powered by freshly ignited hot exhaust, turbochargers and related components get extremely hot themselves, challenging engine oil’s effectiveness. Being more heat resistant, synthetic oil can be more effective for turbocharged engines. 

Synthetic Oil Disadvantages

• Higher Cost
  Synthetic oil sometimes costs twice as much as mineral oil. Unless you stretch your oil changes beyond manufacturer recommendations, the overall cost of oil changes will be higher.

It is important to point out that the idea that once you have synthetic oil in your engine, you never go back to mineral oil is a complete myth. It is perfectly safe to switch between or mix synthetic and mineral oil at any time.  In fact, according to a Consumer Reports survey, 70% of new cars are sold with synthetic oil in them, so it is a good chance your car has already had the switch once. There are also mineral/synthetic blends, which predictably bridge the gap in increased effectiveness and higher cost.

There is little question that synthetic motor oil is superior. Whether it is worth it is the answer you still have to decide for yourself. If you never keep a car past 75,000 miles or so, you may not be concerned with longer engine wear. But if you tow regularly, have a turbocharged engine, are mindful of Plano’s hot Texas summers, or just want to take the best care of your car you can, synthetic oil is probably the way to go. If you still have questions regarding synthetic oil for your Buick or GMC model, contact one of our Ewing Buick GMC service professionals for advice.