Your Engine, Your Baby: Synthetic or Conventional Oil
Posted: Thursday, April 28, 2005
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!
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.
Recently purchased a 1997 Licoln Towncar, 106,000 miles. The dip stick shows a clear oil. No maintenance records. Do not know what kind of oil in the engine. I prefer sunthetic oils. How can I determine what kind of oil is in the engine? Thanks.
Dear Mr. Walker, a common misconception of the meaning of the "W" in the description of the viscosity of the oil in question is that the "W" represents "weight"...however, the numbers represent viscosity. The number 10 is for most temperature environments, and the number 30 for winter temperatures. Hence, the "W" ahead of the number 30. The "W" is for Winter temperatures. I hope that clears the confusion of your readers. For confirmation, check SAE, MOTOR MAG, Chilton, etc......... Brett B. Louisiana
i have corolla 1991 with 300,000 km.since June 2005 I used the synthetic oil 10w30walmart brand tech 2000.Is this brand as good as Mobil 1 or Penzzoil or castrol.SHould I use 20w30?please adviseno its not as good as those brands, but it does the job...its made by shell so its the same thing as shell oils...hope that helps....overall its not a bad oil
hi, I have a 99 Dodge dakota that has 129,000 miles on it. I use 10W30 castrol in it. Is it to late to swith. and do you have to use a different kind of filter for synthetic oils? I live in Vermont where it is 95 in the summer and 0 in the winter and I only drive it 5 miles each day for work. Please leave me an email for help thanks.
The only thing I will add to this article is the fact that conventional oil begins to break down right around 250 degrees farenheit, and if you have ever had a car overheat, you pretty much know you car gets a lot hotter than that. And whereas yes, most people DON'T drive their car that hot, it only takes once for the car to overheat, the conventional oil to break down, and you are stuck with an engine that is most likely dead, but with synthetic oil, it will protect much longer and hotter than a conventional will... It's a great product!!
I just had my car's engine rebuilt about 6 months ago and I filled it up with synthetic oil knowing only the benefits are longer change intervals and much smoother engine operation. A few days ago and to my surprise, my car overheated. I had to drive the overheating car about 2-3 miles to get home. I found out that I had a complete coolant loss due to a rubber plug that had popped off. I shutdown the engine and left the cooling system dry. I was expecting another engine rebuild since the engine might have sustained severe damage due to the overheat especially damaged/blown head gasket. When the engine got cool, I fixed the problem with its cooling system and filled up with coolant. I wanted to check if by some luck, the engine would still be running okay. Well, the engine fired right up when I started it. I even test drove the car and it was as if nothing happened to it. The head gasket was not blown; fluids (oil and water) did not mix; no visible signs of cracks or leakages; and the engine was running smoothly like it was before. I even drove the car hard just to see if anything in the engine would break as a consequence of the overheat. But I was surprised to find out that nothing in the engine got damaged. Heck, I just realized that the synthetic oil I used saved my engine's life. This is a benefit of synthetic oils which I learned the hard way...
the "w" used in oil viscosity refers to the first number. in the examle above it would be the 10 not the 30, you want thinner oil in cold temperatures for increased lubrication at low temperatures.
This article was very enriching!! I currently use synthetic in my 02 Acura RL and your article confirmed what my mechanic told me.
very informative thanks for the article
Thanks a ton, Micheal.. I am writting this from Bangalore, and your article was quite useful to me. Next week, I am taking my TATA Indica Turbo DLX (40, 000 Kms ) car to for checkup and service. My Service advisor suggested Synthetic Oil. I am going for Synthetic. Great Advice. Thanks a ton. Meyyappan / Meyzone@hotmail.com
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