WINTER 2014 | MARINE TECHNICIAN TODAY
17
TECH TALK
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additives it becomes painfully obvious that either the failure of the
base oil or the depletion of additives will result in condemnation of the
oil. Simply put, oils are unique when compared to each other; even if
two synthetics are compared, the choice of synthetic base oil and
the quality and amount of the additives can produce widely varying
finished products.
Oil life is best determined utilizing used oil analysis and then evaluating
the remaining oil life based upon the results of a given analysis. Some
oil companies, like Mobil and Amsoil have amassed significant data
through oil analysis that enables them to make categorical
recommendations for longer drain intervals. It is improper to assume
that, because you are using synthetic oil, it automatically has an extended
drain interval. Some major oil companies – Valvoline is one – are on
record as saying their synthetic oil has the same additive package as their
petroleum; so, the additives in their synthetic oils deplete just as quickly
as their petroleum oils.
Oil Life / Endurance Advantage:
Synthetics (varies between synthetic manufacturer)
PETROLEUM OIL VS SYNTHETIC OIL: COST
What is the real cost to use synthetic oil compared to petroleum? To
correctly assess cost, it is necessary to differentiate between price and
cost. What you pay for an item is the price, how the price is distributed
with respect to product utilization over time is cost. For example, if you
pay $160 for an 80,000-mile radial tire, then that is the price to purchase
the tire. To determine the cost, you have to distribute the $160 over the
80,000miles; this determines the cost permile to use the tire. Thismethod
allows the direct comparison of products that are priced differently yet
have variable life expectancy. Calculating cost is a little of a mixed bag
when comparing synthetic and petroleum oils. Not all synthetic oils are
designed for extended oil drains and some petroleum oils will perform
much better than others. Comparisons are best done on a case-by-case
basis. In general, most any synthetic will run longer between oil drains;
however, only a select few are designed for very long drain intervals. For
the synthetic oil to be equal or less costly, it must have approximately two
to three times the drain interval of a given petroleum oil.
There are other, indirect cost benefits to synthetic oils, including
improved fuel economy and superior lubrication that results in less
maintenance. One unheralded feature of synthetic oil is insurance: by that
I mean protection from unexpected calamities. The blowing of a radiator
hose, the loss of oil or a water pump failure, in most cases, may result in
engine damage from excessively high temperatures. When PAO or Ester
based synthetics are used, engine damage is highly unlikely to result
from engine overheating. This insurance can mean saving thousands of
dollars on repairs.
Cost Advantage:
Synthetic
Comparing the features of synthetic oils versus petroleum oils is an
exercise that all lubrication professionals have fun with, but for the
consumer, what is the bottom line and what action should you take?
Clearly, synthetics win in head-to-head features and benefits and they
also provide intangibles such as insurance but should every owner
switch? The answer is “no.” If you own an older boat with more than
1,000 hours, you should not switch unless you have an experienced
professional to guide you through the process. If you have a boat with
leaks that you cannot fix, then it makes no sense to pour the higher priced
synthetic oil into the bilge. If, for some reason, your engine is consuming
oil at an alarming rate, again, it is not cost-effective to use synthetic oil.
On the other hand, synthetic oils are superior in performance; the right
synthetic is more cost effective than petroleum so there is little reason
not to switch. The high temperatures (> 600°F) possible in the turbo-
charger make synthetic oils (PAO and/or Ester) clearly the best choice;
one failed turbo buys a lot of synthetic oil. If you are involved in severe
duty operations, then synthetics offer so many superior benefits and
enhanced protection that it is the only right choice. Using petroleum oil vs
synthetic oil is an option analogous to using bias ply tires instead of radial
tires. Of course the bias ply tire can get you from point A to point B. The
difference is in the load carrying capacities, heat range, traction, handling
and tread life. For simple casual driving with no severe conditions the
bias ply tire may work fine but in the event of something outside normal
conditions, the radial is superior; it is simply a matter of the quality of
each tire’s construction.
PETROLEUM OIL VS SYNTHETIC OIL:
DECISION TIME
The decision, whether to use petroleum oil vs synthetic oil,
is dependent on your unique situation; each of us has his own
set of circumstances to assess in order to make a decision based
on facts. Understanding the benefits and limitations of engine
oil will help you make an informed choice. Making sense of the
relationships between oil properties and how those properties
protect and preserve an engine is the only real way to analyze
true cost effectiveness. Sometimes the decision is obvious; severe
duty situations call for synthetic oils. Critical components subject
to high temperatures like the turbo-charger are best protected by
synthetics. I recommend synthetic engine oils in order to provide the
most cost effective method to achieve the best lubrication possible
for your marine engine.
For questions or comments contact Dan Watson, Certified Lubrication
Specialists STLE, at the following:
, 800-370-2986
or
