Synthetic lubricants have been around for decades, but many people can't quite bring themselves to give them a try—for two reasons:
Synthetics have more than three times the cost of petroleum lubricants. This sticker shock is often enough to shut down any interest a driver might have in using synthetics. Too bad because in the long run they cost about the same as oil because they last about three times as long as conventional oils before they have to be drained and replaced. One reason is synthetics have a lower volatility and don't boil off or vaporize as fast as petroleum motor oils. And keep in mind, overall driving costs can be less with synthetics when you factor in how much they can improve performance.
By the way, the environmental cost of synthetics is also probably less. Oil is derived from petroleum, and synthetics come from chemicals that aren't much good for the environment, either, so the two are about equal in how much pollution they create. This is a lot when you consider that the Pennsylvania Department of Environmental Protection says that 85 percent of the motor oil drained by backyard mechanics is not disposed of properly—and therefore is a major player in groundwater pollution. However, environmentalists like synthetics because they last longer and are drained and disposed of less often than conventional oil.
Many motorists still don't know much about synthetics and are amazed when they find out that, according to independent university and industry testing, the benefits of using one synthetic brand, when compared to conventional motor oils, typically include:
- Increased horsepower and torque by as much as 3%
- Reduced engine wear by as much as 80%
- Improved fuel economy by as much as 5%
- Reduced engine heat by as much as 10%
- Reduced emissions by up to 20%
Synthetic lubricants, be they motor oils or gear oils, offer these advantages because of the basic uniform molecular structure of synthetic base oils, as opposed to the varying shape and size of the mineral-based oil's molecules (see illustration). The uniform molecular structure decreases friction, improves heat transfer and provides greater oxidation stability for longer oil life.
With gear lube, synthetics also are superior to traditional. Studies show that synthetics rule when it comes to testing how well a variety of synthetic and conventional lubes perform in maintaining viscosity with temperature changes and during use, functioning in the cold, resisting oxidation, protecting against wear and extreme pressures and resisting foaming and copper corrosion. And because vehicles come packed with ever-increasing horsepower, towing capacity and hauling limits, differentials are being stressed like never before. A superior, longer-lasting gear lube will help reduce maintenance of differentials and make them last longer.