by Ed Newman – AMSOIL Director of Advertising

This article appeared in National Oil & Lube News, December 2009

If you spend any amount of time on the internet you will sooner or later come across a page called FAQ, which is shorthand for Frequently Asked Questions. The purpose of the FAQ page is to relieve tech support people from having to answer the same questions over and over again, and to make it easy for customers to find answers on their own.

Here are some of the typical questions we’ve received over the years.

Q: What is the difference between synthetic motor oil and conventional petroleum oil?

A: Synthetic lubricants are composed of select base stocks and special purpose additives chemically assembled with planned, predictable properties. Whereas petroleum oils are pumped from the earth and refined, synthetics are custom-designed in the laboratory, with each phase of their molecular construction programmed to produce, in effect, the ideal lubricant.

Q: What are some of the common misconceptions about synthetic motor oil?

A: It is interesting how some of these myths hang around for so many years. Some of the most common were that synthetics are not compatible with seals (properly formulated synthetics actually extend seal life), that synthetics are too thin to stay in the engine, and that synthetics cause cars to use more oil. Of course there are misconceptions going the other direction, too. Some people think synthetic oil is a super oil that will last forever. It is true that synthetic oils are more impervious to oxidation, but the additives in synthetic formulations do get used up over time. A motor oil’s formulation includes the performance of both the base stock and additive package.

Q: If a car is factory fill conventional petroleum, will switching to synthetic void the warranty?

A: No, it will not. Vehicle manufacturers recommend using motor oils that meet certain viscosity grades and American Petroleum Institute service requirements. Whether the motor oil is petroleum-based or synthetic will not affect warranty coverage. The manufacturer is required to cover all equipment failures it would normally cover as long as the oil was not the cause of the failure.

Q: Is there any truth to the notion that cars should be running petroleum oil during the break in period before switching to synthetic?

A: A premium synthetic motor oil can be used during break-in without any trouble. In fact, dozens of vehicle models come factory-filled with synthetic oil now. Rebuilt engines may still require break in oils that don’t prevent wear as well and will allow rings to seat, but not factory supplied engines.

Since a majority of new vehicles come filled with petroleum oil, it only makes good sense to change to synthetic at the first scheduled oil change interval. New engine components generate high levels of wear metals and can contain contaminants from assembly. By allowing the engine to operate with the petroleum oil until the first oil/filter change interval, the wear metals and contaminants are removed prior to installing the premium product.

Q: Will switching from petroleum to synthetic result in a plugged oil filter when the sludge is cleaned out by the synthetic?

A: This is a common fear, however, switching from petroleum oil to premium synthetics in routinely maintained vehicles will not cause clogged oil filters or passageways, regardless of mileage. Sludge, which is caused by poor quality oil and neglected maintenance practices, would have to be present in significant amounts to plug oil filters and passageways. If there is an excessive amount of sludge present in an engine, it is just a matter of time before oil filters and passageways clog, regardless of the oil you choose.

Q: Will switching to synthetics cause my engine to leak oil?

A: In mechanically sound engines, there’s no risk of synthetic motor oil leaking. In fact, premium synthetic oils are fully compatible with modern seal materials, keeping them pliable to prevent leakage. New engines are built to much tighter tolerances now than they were in the 70’s and 80’s when that notion was promulgated, and is not true anymore.

Q: Is there a recommended procedure for switching to synthetic motor oils?

A. As long as the vehicle has been properly maintained and the vehicle is mechanically sound, there are no special requirements. Some oil manufacturers, however, may indicate specific drain intervals that should be followed for vehicles that have over 100,000 miles and are first time users of their products.

Q: If someone switches to synthetic can they switch back to conventional oil?

A: Yes, they can, but why would anyone want to?