The automakers of many newer vehicles are recommending use of synthetic oils in those vehicles. Synthetic oils cost more which leads some consumers to question their value. Why are they being recommended and are they worth the cost?
Synthetic oils are lubricants made of chemical compounds that have been artificially made instead of naturally formed. There’s a wide range of “base stocks” that can be made in this manner, by taking petroleum building blocks and “synthesizing” high quality base oils from those. The first synthetic oil approved for use in regular cars and trucks was made in 1972.
Is synthetic oil worth it? Generally speaking, synthetic oils are better quality than conventional motor oils, because by creating them in a manufacturing process, their quality can be controlled and streamlined much more so than making oil from whatever nature has created underground. Synthetic oils can be tailored for a specific need in whatever class of vehicle they’re being used in. The molecules are all the same size and shape, and so that enables the synthetic oil to withstand engine extremes better.
Synthetic oils tend to have better high and low-end viscosity performance in very hot and very cold weather. These oils are more resistant to wear and breakdown by oxidation (because they’re engineered to be so) and some synthetic oils can improve fuel economy. They are also more resistant to sludge formation because of this resistance to oxidation and they disperse sludge particles at least as well as regular oil.
The biggest downside to using synthetics is the cost difference with regular oil. But something you get what you pay for. Any other negatives to synthetics tend to be minor issues – you can’t use them in rotary engines (like Mazda), they have less friction so you can’t use them in the break-in period of a new engine.
There have been tests run where it has been shown that synthetic oil gives you a little better gain in horsepower and mileage than conventional oils do. While the gain is measureable, one must be careful not to oversell these benefits.
Detractors of synthetic oils have argued in the past that they aren’t compatible with conventional oils. This has been shown in field experience not to be true. Today’s synthetic oils are fully compatible with conventional oils. Synthetics are also completely compatible with oil treatments like Bell Performance X-tra Lube. Customers have used X-tra Lube oil treatment in synthetic oil and have received the full benefits of X-tra Lube’s MBL technology without any issues.
If your owner’s manual specifies synthetic oil for your vehicle, that’s what you need to go with. If it does not, then it’s up to you if you want to cover the extra expense for the extra benefits. Some people do, some people do not.