Your Engine, Your Baby: Synthetic or Conventional Oil - by Michael Walker

One central argument between car enthusiasts and on Internet car forums alike is what oil is better for your car, synthetic or conventional. Before synthetic oils became available for regular automobiles, the argument centered solely on brand types and weight. But now, with the advent of these synthetics all over the market, what is truly the best choice for your engine? Let’s explore both of these worlds to find out.

Conventional oil is rated according to a SAE system. This scale is used so that you know what type of oil is best for your car given the environmental conditions (temperature, city driving, etc.) of where you live. The first number, for example on 10W30 motor oil, is 10 followed by a “W”. This “W” indicates that the number before it is the viscosity rating of the oil. The lower this number, the better the oil is for colder climates. The higher the number, the better it is for hotter driving conditions.

Synthetic oils, on the other hand (before their commercial release) were used in many military vehicles and fighter jets. Airlines also use synthetics in their engines. The synthetic oil has been designed not to break down as quickly and can tolerate extremities in temperature and weather (hot to cold).

One of the major differences between conventional and synthetic oils is that synthetics are treated with more additives that protect your engine for a longer amount of time before you have to change it. And, while we don’t want to get into all the molecular chemistry involved in the making of these oils, we should mention that they also last longer in hotter conditions and won’t “gel” in colder ones, like conventional oil. In other words, synthetics have more additives, which greatly protect the car from viscosity breakdown. They are designed to withstand temperature extremes. It may be safe to say that extreme driving conditions call for the use of synthetics.

On the financial side of the matter, synthetics cost a whole lot more; up to three or four times as much as regular conventional oil. But, the wonderful thing is that you don’t have to change your oil every 3,000 miles; recommended with conventional oil use. In fact, you may not have to change it until well after 25,000 and up to 50,000 miles as long as the oil filter is changed every 10,000 miles. So, the cost at first might scare consumers away, but the long-term benefits of synthetic oil use are substantial.

However, you will still have to be responsible for your car’s maintenance check-up every 3,000 miles or so. With regular oil-changes, you are automatically checking over the car for other problems (or if you don’t an inspection mechanic does). It might help you find a problem that could be dealt with, that could’ve gone unchecked. Also, you’ll want to check the synthetic oil every now and then to be sure that it isn’t contaminated and/or that there isn’t any moisture build-up.

With normal everyday driving, perhaps conventional oils work best for you. You aren’t driving in extreme conditions and you swear allegiance to regular oil. That may be fine. Synthetic oil cannot really offer you anything that conventional oil cannot under normal operating conditions. However, the definition of extreme driving states that if you do a lot of short driving (two to twenty miles) daily, it’s hard on your car. And, specialists agree that this constitutes extreme driving due to the faster breakdown of the structure of conventional oil.

Another major reason that many are choosing the synthetic route is that it contains fewer impurities; impurities that can cause your engine harm, perhaps to the point of premature engine wear. With conventional oil, there’s no way to totally rid, filter or clean the impurities from the natural elements. That’s another reason why synthetic oils do not have to be changed as much even in extreme driving conditions.

You’ll want to be careful; however, if you do decide that you want to give synthetic oils a try. If you’ve been driving your 1983 Ford Thunderbird for years using 10W30, you may not want to switch using your conventional oil brand.

Conventional oils have solvents that stick to gaskets and seals and often cause them to swell a certain way. These gaskets and seals have been used to the same oil for years and the switch to any other type of oil (whether it is to a different conventional oil brand, or an upgrade to a synthetic) may be harmful. The oil you change (or upgrade to) will also have solvents and additives, different from the original. So in other terms, the changing of oils could result in oil leaks and/or a once small oil leak becoming bigger due to the reaction the seals and gaskets will have to the change (not because of the oil itself). If you think that this might be the case for you (i.e. if you have an older car using conventional oil), it’s recommended that you not try synthetic oil until you have an engine (or new car) with relatively virgin gaskets and seals that will be able to acclimate much more easily to the chemical changes of the newer type of oil.

It’s easy to see that that fanfare for one or the other is an argument that has really been explored. It’s best for you to decide what will fit your personal needs. If you have an older car, you may want to wait until you upgrade. However, if you have a newer car, the benefits of synthetic oils are easily seen. Again, it’s solely dependent upon you and the conditions where you drive. Synthetics are shown to provide their best protection above 250 degrees Fahrenheit. Most people do not drive their cars this hot. However, many do drive in cities, where driving times are considered to be more of a “stop-and-go” nature, which may be considered “extreme” in many circumstances. When the time comes for you to make a decision, at least you’ll be informed of the differences of each. And, until that time, no matter what, keep up that automotive pride!

About the Author

Michael Walker is a freelance author providing tips and hints on engine related topics such as JDM motors, used import engines and engine swaps. His articles are a valuable source of information for the auto enthusiast.