|Multi-Viscosity is the way to go.
There are two types of lubrication that motor oil gives to your engine. The first type is
called a 'Hydro-Static Boundary Layer'. That simply means the viscosity of the oil, which
is defined as resistance to flow, is what is causing the oil to cling to the inside
surfaces of your engine while the engine is turned off and the oil pump is not operating.
When your engine is first started, this 'Static' layer of protection will give the engine
adequate lubrication for a few minutes (5 or so) until the oil pump has the ability to
create enough oil pressure to get the heated oil moving up into the upper parts of your
point, the second type of lubrication takes over. The oil pump is forcing the moving oil
in between the engine's internal components, creating what is called a 'Hydro-Dynamic
Boundary Layer'. That simply means oil is moving around by way of the oil pump. With a
single-grade oil, the heat from operation thins the oil that is clinging to the upper
parts of the engine quickly, much more quickly than the oil in the pan. This reduces its
viscosity, or ability to flow and causes the engine to lose its 'Hydro-Static Boundary
Layer' of lubrication. Unfortunately, the relatively thick single-grade 30-weight has not
warmed up enough in the pan to be easily pumped up to the upper-engine before the 'Static'
layer is depleted. So what you have is an engine that has lost its 'static' lubrication,
but is not receiving any adequate 'dynamic' lubrication yet. This creates and abundance of
wear and tear. This is why most engines from the 50's and 60's would be all used up at
around 50,000-75,000 miles. That, and the high sulfur and phosphorous trace elements in
the oil. Multi-viscosity oil nearly perfectly solves this problem. By starting out at a
relatively thin weight, such as 5 or 10, the oil will be very easily and quickly pumped up
to the critical parts of the engine, creating the 'dynamic' layer of protection long
before the 'static' layer of protection is gone. Through the use of man-made additives
called 'Viscosity Index Improvers' (long chain coil polymers, which are
temperature-reactive), the oil will increase its viscosity as it heats up to its full
operating temperature. Operating temperature for motor oil is 150 degrees. This 'overlap'
of boundary layers of protection is what has enabled engines to go for 250,000-400,000
miles on a regular basis, along with much better refined oil. Basically, it has taken
almost all of the wear and tear out of the warm-up phase of engine operation, which is
where 75% of all internal engine wear comes from. All is not perfect, however: The V.I.
Improvers are man-made additives and are VERY susceptible to the mechanical and very
destructive 'shearing' action of the engine. This 'shearing' action actually tears apart
the additive package, including the V.I. Improvers after a certain amount of time. Driving
habits, engine type and condition make an enormous difference in how long the additive
package will function adequately, but 3 months-3,000 miles is a good rule of thumb for the
typical city and highway driven vehicle. All city driving (stop and go, idling, etc...)
will shorten the oils life dramatically by as much as 33%. Oil changes every 2,000 miles
may not be excessive under those circumstances. On the other hand, mostly highway driving
at relatively steady speeds on flat paved and dust-free roads is the best condition for
your engine and its oil. This may allow you to increase the drain interval by as much as
The wider the range of viscosities
on the oil, the less durable and resistant it is to 'Viscosity Index Breakdown'. For
example, 10W-30 oil does not have as much 'V.I. Improver' as 5W-30, so there are fewer
additives to be broken down by the shearing of the engine. In fact, 10W-30 is by far the
most 'durable' multi-vis oil there is. You should try to stay away from the wider spreads
like 15W-50, 20W-50 and especially the 5W-50.
Also, thicker is not better, no
matter what your mechanic or engineer told you. 20W-50 has 40% more viscosity (resistance
to flow) at operating temperature than 10W-30. This means that your engine has to work 40%
harder just to move the oil around inside your engine. An engine with thick 'oil' produces
significantly less power, uses more fuel, produces more emissions and runs hotter, all
contributing to shorter engine life. A thinner oil can more easily and quickly be
'pumped-up' to the critical parts of the engine, takes less energy to move it around,
helps the engine to produce more power, less emissions, better economy. And the engine
will last longer too! This has been proven numerous times in test after test, by many
different and highly respected testing facilities. Unfortunately, the rule that 'you can't
teach an old dog new tricks' prevents many 'experts' from accepting the facts. Indeed,
when I was a kid, it was Castrol GTX 20W-50 in every car I had! In the years since, I have
been working in the automotive lubrication industry, (15 years now) have been on the
engineering boards of several major motor oil manufacturers. I feel lucky that I was able
to 'see the light'.
Indeed, my '71 429 Mustang
historically got about 10-11 MPG while it was run on 'dino' 20W-50. Now that I run nothing
but Mobil 1 full synthetic in everything I own, my Mustang now gets about 17-18 MPG, and
runs cooler to boot! That is significant. Unless your car is an actual bonafide 'RACE
CAR'- no city driving, no idling, no stop and go traffic, no foul weather driving, etc...-
Do NOT use 'racing' oil in your engine. Racing oil has a very narrow and specific additive
package designed for engines that are used in racing situations, like constant high rpm
operation, steady speeds, no stop and go, no foul weather, etc... The oil that is designed
for passenger cars is immensely more sophisticated than 'racing' oil, only because it has
to function under an almost impossible array of conditions.
If you drive your car on the street
most of the time, a good passenger car, or maybe 'high performance' oil will be much
better for you than any 'racing' oil.
The first number is the weight of
the oil at cold start-up, so a lower number means a thinner oil that will be pumped up
The second number is the viscosity
(sic) of the oil once it has reached operating temperature (150 degrees).
The additive 'V.I. Improver' helps
it to do the opposite of what it wants to do when it warms up, which is thin out.
These types of oils are classified
as 'non-Newtonian' because of this ability.
5W-30 or 10W-30 is better in colder
climes. By the way, the 'W' does not stand for 'weight', as many erroneously assume. In
fact, the 'W' that is in the S.A.E. designation for an oils viscosity stands for 'winter',
indicating that the oil will flow at its rated viscosity in 'winter driving conditions',
as defined by the S.A.E.
Now, the first number in a
multi-vis oil describes its viscometrics at cold start-up. (engine off for 4 hours or
longer, regardless of the outside ambient temperature)
The second number describes it
performance at operating temperature. This is where a lot of people get confused.
In a properly running engine with a
properly functioning cooling system, it doesn't matter if you are driving in sub-zero
temperature or 100 degree heat. The design of the cooling system will cause the engine
& coolant, and therefore the oil to operate at whatever temperature it was designed to
operate at. So what I'm saying is that the first number is critical in terms of climate.
That is why the 'W'(winter) designation is put after the first number, not at the end. The
second number has almost no correlation to ambient temperature, only the regulated
temperature of the engine.
Now a little trial and error will
tell you exactly what weight of oil will best work in your car.
For the first 500 or so miles after
a fresh oil and filter change, the most volatile compounds of the motor oil will
'volatize' (boil off). This relatively rapid oil consumption will then taper off into the
norm for that engine. So just top it off after 300-500 miles and then start the 'test':
Make sure that the oil is exactly
on the full mark of your dipstick at 'zero' miles of the beginning of the test. Check it
at 500 miles, 1,000 miles and again at 1,500 miles. Do not top it off at any time unless
it falls dangerously low. (1 quart or more).
If you find that your engine is
using oil at a faster rate than normal (1 quart/3,000 miles), then try using an oil with
10 viscosity points higher in the second number.
As an example: start with 10W-30,
and at 500 miles top it off. If 1,000 miles later you are a quart or half a quart low,
record it and continue with the test. At 3,000 miles, if you have had to add more than a
quart counting from the first 500 mile top-off, then you should use 10W-40 on the
succeeding oil change.
Record your results again. If the
10W-40 does not volatize as readily then you should stick with that. However, if it still
burns away, then try 20W-50.
But, if the 10W-30 does NOT burn
off too rapidly, then you should stick with that. No need to put thicker oil in if its
serves no purpose right?
Of course, this is all assuming
that your engine is in fairly sound operating condition. If your engine has worn or bad
rings, or worn valve guides this test will not be conclusive.
And if your choke is not adjusted
correctly, you may get a large amount of unburned gasoline pumped into your oil, which is
TERRIBLE for your engine. Fuel-diluted oil is one of the worst things that damage your
engine. Gas is a solvent, and solvents cut the lubricity of oil-the exact opposite of what
you want. If you can smell gas in your oil (on the dip stick), you are WAY past due for an
Synthetic oils, only oils that are
made using the 'PAO' method are truly considered to be synthetic. Castrol Synthetic
'Syntec' is NOT synthetic oil. It is simply a 'Group II base stock' that has been further
refined using propane de-waxing and severe hydro-treating to give a better base stock. But
is still refined from paraffinic crude, as all conventional 'dino' motor oil is. Although
the US FTC allows Castrol to call it 'synthetic', it cannot be labeled as synthetic in
Europe. It has a different name over there.
Mobil 1, Sheaffers, and Royal
Purple are all good synthetics.
I stay away from Amsoil for reasons
that are far too detailed. OK, I did not say that there was anything wrong with Amsoil. I
just don't like for personal reasons, and I guess I'll explain why.
Most 'dino' oils have about 20-25%
additives, depending on viscosity and brand. But that figure is almost universal. Motor
oil performs five functions in your engine:
3) Keeps a clean engine clean
5) Protects (w/additives)
As most already know, the crude is
refined to whatever degree is financially reasonable, creating the 'base stocks'. Then the
additive package is introduced to further improve and modify the oils abilities.
The major improvements in refining
technologies over the years have produced very clean and high-quality base stocks, but
that is still not enough. If you could somehow get a hold of motor oil with no additives
(like those produced before 1961) and run it in your modern engine, your engine would
self-destruct in a short amount of time.
So additives are a very important
part of the oil.
Here's a shocker: The actual oil in
your engine never wears out! It will always be oil.
There are 3 things that make motor
oil unfit for continued use in an engine:
1) The additive package becomes
depleted and can no longer offer all the performance and wear improvements necessary.
2) The oil becomes overly
contaminated with particulate matter, combustion by-products, corrosive acids, dust, dirt,
silica (VERY damaging!), and sludge. The sludge is a direct result of the combination of
heat, air, water and petroleum (which is chemically the reactive trace elements left in
the crude after refining: Sulfur and Phosphorous are the big ones).
3) The oil becomes fuel diluted
with raw gasoline. Gas does not lubricate and an oil filter does not filter-out gas. Gas
goes right through undeterred. An oil filter is designed to filter out particulate matter
only. Cars that are driven mainly in the city with a lot of low-speed driving, a lot of
traffic lights, and do a lot of idling tend to put a lot more unburned gas into the oil.
It is common for cars to burn a considerable amount of oil because it has become fuel
diluted, reducing its ability to lubricate. Then, because the thinned-out oil cannot seal
as well, it will let even more unburned fuel and contaminates past the rings, and more of
the oil will burn away. The gas being introduced will sometimes take the 'place' of the
oil, and when you look on your dipstick, you see that it is 'full'. This will lead some to
believe that their car does not burn oil.
Then, in this example, say you take
this car on a 75 mile highway trip and when you get there, you check the oil only to find
out that it is 2 or more quarts low! This concerns you, because the car has never burned
oil before. So you add a couple of quarts, putting good clean gasoline-free motor oil in
its place with nice and new robust additives. You drive home the 75 miles at a little
slower speeds because you are concerned about the oil loss. When you get home, you are
fully expecting to see a 2 quart loss. But you are surprised to see that it is still on
the full mark! So now you are confused. Many will blame the brand of oil, the shop who did
the change by installing the 'cheapo' house brand, and some will just scratch their heads
in wonderment. Fuel dilution is the culprit. In reality, the fresh oil helped to seal
well, lubricate better and prevent excess oil loss.
Highway driven cars are not nearly
as susceptible to fuel-dilution problems, as the heat burns the dilution out of the oil.
So anyway, what I am saying is that
it is the additive package that 'wears out', not the oil itself. Mobil 1 has about 10-12%
additives, far less than 'dino' oil, because the synthetic base stocks are much, much
closer to 'perfect' and able to do an outstanding job without the use of nearly as many
additives, which can be thought of as modifiers or 'band-aids'. This higher percentage of
actual OIL in the Mobil 1 formula lets the oil lubricate and cool your engine better. That
is why engines that use a good synthetic get noticeably better mileage, run cooler, last
longer, make more power, and produce fewer emissions. But to me, the most important reason
that I use Mobil 1 is because there are no trace elements in it. None! Remember, it is the
sulfur and phosphorous that helps lead to sludge formation in an engine. Without these
trace elements in the oil, the formation of sludge is remarkably reduced. Engines that are
run exclusively on Mobil 1 stay unbelievably clean and sludge-free. Sludge is far and away
the leading cause of engine failure. That's why I don't like the Castrol synthetic
product: It still contains many trace elements. Now Amsoil advertises that their oil is
the 'extended drain interval' oil. They do this by pumping up the additive package. They
can have as much as 3 times as many additives as Mobil 1, so in theory it can take more
'shearing', lasting longer. More additives means less actual oil in the mix, resulting in
less lubrication, less cooling, more wear and tear...you know the rest. The oil may last
longer, but at what price? Your engine? That's not a good trade off for me. Don't get me
wrong. Amsoil is a very good oil, but no matter how good any oil is, your engine is still
going to produce contaminants and by-products, and the longer they are in your engine the
more damage being done.
I have been involved with motor
oil, oil manufacturing and testing, and additive technology for about 15 years or so. I
spent a considerable amount of time at the Texaco lubrication and additive research and
development facility in the Catskills, which was awesome. They have several fully
computerized vehicle dynos there that can simulate any kind of driving environment. A few
of the dynos are in sealed rooms, and they can add rain, snow sleet, blistering heat,
rough terrain...just about anything you can imagine, all at the touch of a button from a
separate control booth. These dynos run non-stop, 24 hours a day performing long-term
evaluations. Pretty cool stuff, all in all.
My Sears tractor-mower is about 20
years old, and I have been putting fresh 10W-30 synthetic in it every 3 months for about
15 years now. It only holds about a quart. The only reason I switched to 10W-30 syn is
because that is always what I have around the garage. Once I made the switch however, I
noticed that it started much easier, runs quieter and doesn't seem to get as hot. I have
no clue about the B.G.P.G. (Blades of Grass Per Gallon). Never had a single problem with
it, so I guess it's OK. I could be imagining it, but I don't think so. I try to pay close
attention to these things.
There are a lot of things to
consider when it comes to motor oil, to know the truth. There is so much detailed info to
know that the oil companies know the average consumer would never put forth the effort to
really understand oil, so they don't even try to sell it that way. They just come up with
generic, 1-size-fits-all ad campaigns, so 'Joe Consumer' will stay just uneducated enough
to think that there are really major differences between brands. In reality, as long as
the oil has the 'API' donut on the back label, nothing else really matters. The front
label is totally worthless as far as a source of useful information. Most of the
differences between brands is in the additive packages, and even then, the differences are
relatively minute, as long as you are comparing similar types of oil from competing
brands. The very best oil out there is not a whole lot better than the worst, as long as
it meets the API and SAE classifications. For all you guys out there that are looking to
use some great oil at a great price... I have a shocker for you: The oil that Wal-Mart
sells under their house name (Super-Tech) is very good quality oil. In many tests done
over the last year or so, the 'Super-Tech' oil was superior to many name-brand oils. The
oil is supplied to Wal-Mart by Pennzoil/Quaker-State. It uses the same high-quality group
II/III base stocks as their name oil, but uses an off-the shelf additive package. That
doesn't mean it is lesser than the 'Z-7' or whatever additive package they advertise
about. Most oil companies register their particular name-brand additive package formulas,
so they cannot be 'copied' by another manufacturer. That way they can advertise about
'Nothing is the same as...' and all that kind of crap. An off the shelf package is
available to whatever packager wants to buy it. So it is a little more economical for the
packager. This also prevents stores like Pep-Boys, Wal-Mart etc...from advertising that
their 'house' oil is 'same as Q/S but at a cheaper price.' Wal-Mart's 'Super-Tech' dino
oil is less than a buck a quart, and their synthetic brand is $2.97/Qt. Great deal. Their
'Super-Tech' oil filters are also very high quality, unfortunately much better than Fram.
Fram has really gone downhill in the last several years, ever since 'Allied-Signal' bought
them. At less than $3.00 apiece, the 'S-T' filters are a smokin' bargain.
I use Mobil 1 in my real nice cars,
and Super-Tech full synthetic in everything else. And I use Super-Tech filters on
everything. I fully expect everyone who reads this to claim that I am full of beans (or
something else!), and that I don't know what I am talking about. Actually, I do. But, you
know what they say..."You can't teach an old dog new tricks!"
Assuming that you're rebuilt engine
is stock or close to it, I would use a good quality 10W-30 'dino' (conventional) oil until
there is about 10-12,000 miles accumulated on the engine. There is a rather complicated
reason for this, but not exactly the reason a lot of guys think.
No matter how well the parts are
manufactured, or how meticulous your engine builder is in maintaining his tolerances, the
internals of your engine still have a lot of relatively 'rough' friction surfaces when
freshly put together. I'm talking about rings, cams, rockers, and bearings...stuff like
that. There is a lot of processes manufacturers put their parts through to ensure that
they have the desired 'hardness' that is required for long life: Heat treating,
'Tuftriding', things like that. Anyway, for approximately the first 10-12,000 miles of a
fresh engine's life, the parts all go through a combination of physical and molecular
changes. First, there is a tremendous (relatively speaking) amount of friction on these
surfaces for the first 12K, and the result is that the parts are reaching what engineers
call 'equilibrium'. The parts are wearing into a state of near perfect smoothness, in
relation to each other. Much more perfectly smooth than any manufacturer could ever
produce. Secondly, as this first 12K elapses the internal parts of the engine are also
going through a 'molecular' change (for want of a better word): The best hardening
processes used by manufacturers cannot achieve what the constant heat and operation of 12K
can put the parts through. The parts will become even more hardened, and much more
resistant to wear and tear. But they also become more brittle. For those reasons, it is
vitally important that you operate your car in a variety of driving styles during this
high-friction break-in period to ensure that the internals are fully worn-in, or 'seated'
by the time 'equilibrium' sets in. If the parts are not fully worn-in by that time, then
the new-found brittleness will cause an excess of wear and tear, shortening the engine's
life. For that reason, it is a good idea to stick with regular 'dino' for the break-in
period, so that you will have enough friction to wear in the parts, but not so much that
you are damaging the engine. Since there is so much friction, and therefore much more
microscopic (but still damaging!) particulate matter present in the oil, I would recommend
changing it at the first 200 miles, then at 500 miles, and then every 1,000-1,500 miles
until you have reached about 12K. At this point, you have done everything possible to help
your engine reach as near a perfect state of 'equilibrium' as possible, and no more
break-in is necessary. That means that now you want to have as little internal friction as
possible. At this point, switch to a good full synthetic. Synthetic lubricates MUCH better
than any conventional oil, which of course reduces internal friction. An engine that is
properly broken in and in good operating condition, and with fresh fluids in it will
suffer practically NO wear and tear for many thousands of miles. Synthetic also does not
have any of the damaging trace elements in it (phosphorous, sulfur, etc...) that helps to
create sludge and corrosive acids when combined with the by-products of combustion. The
phosphorous, when combined with the remnants of the unburned hydro-carbons (gas), and then
oxidized creates an acid that is chemically identical to battery acid. This most often
leads to premature bearing failure and excessive cam wear. Since there is more actual oil
in a full synthetic formula, there is more lubrication available to you. Plus, the
relatively 'pure' base stocks do not introduce any unwanted elements into your engine.
'P.A.O.'Synthesized oil is made of
uniformly medium-sized molecules that all react in exactly a known fashion. The very
small, highly volatile molecules that are present in 'dino' are what escape past the rings
causing high oil consumption. This is known as 'volatizing'. There are additives in 'dino'
that try to prevent this as much as possible. However, these all contribute to high
consumption for the first 500 miles or so after an oil change as these light weight guys
all quickly burn off. The very large, slow-moving paraffinic (wax) molecules in 'dino' are
the ones that stick together at low temperature, thickening the oil and preventing it from
being easily and quickly pumped to vital areas of the engine. By low temperature, I do not
mean sub-zero. I'm talking about ambient temperature at 'cold start-up', even in 100
degree outside heat. Additives such as 'pour-point depressants' are included to prevent
this. At high temperatures, 'dino' oxidizes extremely rapidly. The oil absorbs oxygen
right out of the air. Oxidized oil does not lubricate well, in fact it is thick and gooey,
just the opposite of what we want, right? Keeping your oil at a reasonable operating
temperature is vitally important to prevent oxidation, for at low temperatures, oil is
almost totally resistant to oxidation. Higher capacities and oil coolers are both
excellent ways to accomplish this, as most already know. All of these things happening in
unison often create a common situation: Oil is used for too long a period and is exposed
to extreme heat for too long a period and becomes overly oxidized, dramatically raising
its viscosity. What started as relatively light weight 10W-30 may now be a straight 50
weight, all thick, sticky and gooey. This creates less-than-acceptable sealing performance
from the oil, therefore allowing an excess of combustion by-products to 'blow-by' the
rings into the crankcase. This blow-by introduces unburned fuel into the oil an
accelerated rate, and since gas is a solvent, it cuts the lubricity of the thick,
overly-oxidized oil down to maybe a straight 30 or 40 weight. So when an average consumer
hears that Ford claims his new car can go 7,500 miles between oil changes, and 15,000
miles between filter changes, he checks the oil frequently to make sure that the level and
condition are adequate. Lets say he checks at 5,000 miles and finds the level acceptable,
doesn't seem too dark or sticky, and assumes that Ford now makes better engines. Wow! In
reality, what he was looking at was heavily oxidized and fuel diluted oil. The fuel
dilution causes the old oil to feel thin and 'oily', not sticky, Plus it gives it a
somewhat lighter color, fooling him. The gas, of course, prevents proper lubrication,
increasing wear and tear. Additionally, the additive package is all but totally depleted
by now, offering none of the long term benefits of clean oil. Fortunately, ALL of these
terrible things can be totally avoided with frequent oil and filter changes!
A word about synthetics: Only oils
that are created using Poly-Alpha-Olefin based technology are considered to be
'synthetic'. At least by anyone who knows better. The Castrol 'Syntec' synthetic oil is
actually just a much more thoroughly refined 'dino', coming from the same crude that all
conventional 'dinos' come from. Even though their base stocks closely approach the
performance of PAO synthetics, they still contain trace elements, and are still
susceptible to the effects of temperature extremes that full synthetics are almost immune
to. By the way, Castrol does not make their own oil. They never have. They don't even own
a single refinery. Never have. They simply buy their base stocks from one of the
commercial suppliers (Coastal-Unilube is one), buy a custom-blended additive package from
an additive supplier, and have a bottler package and label it all for them. That doesn't
mean that it isn't any good. It is very good. But in repeated testing, the Castrol
products exhibit a wide variance in performance, the results of getting their products
from many different suppliers. 'Syntec' may be good, even excellent oil...but it sure
ain't synthetic! The same was true for Texaco 'Havoline' oil for a couple of years: Two
separate companies were legally allowed to manufacture and distribute 'Havoline' oil.
Shell was one, Equilon was the other. The Equilon-sourced product was far superior to the
Shell-sourced product in every single performance category in repeated tests.
Unfortunately, there was no way for the average consumer to determine which supplier his
'Havoline' was coming from, for the labels were quickly changed to remove this
information. This is all a moot point now for Shell is the sole supplier of 'Havoline'
branded oil now. I just stick with Mobil 1, and that 'other stuff' I talked about earlier.
Porsche, along with most other
European manufacturers typically recommend extended drain intervals, such as the 15,000
mile interval that you are talking about. Driving conditions and the typical driver's
habits are markedly different from those in America. The bulk of driving conditions in
Europe is on high-speed highways, with a small amount of city-type driving. This is the
best driving conditions for oil and therefore an engine. American driving typically
consists mostly of city and traffic-jam driving which is the absolute worst kind of
driving. That is why American manufacturers are slow to come around the same extended
length oil drain intervals as their European counterparts. But they are coming around. The
extended drain interval also allows manufacturers to advertise a lower maintenance cost to
the consumer, which is a powerful sales tool. Of course, these are under ideal 'normal'
driving conditions, which are almost totally non-existent in reality. That's why there are
always 'severe' driving schedules, or a 'B' schedule in most owner's manuals. As far as
the Porsche's engine using higher quality components and manufacturing? You bet they do!
What do you think you are paying for? But that doesn't mean that they are indestructible.
Remember, when a manufacturer says "Change your oil every 15,000 miles", they
are not claiming that the car's engine will last indefinitely. They are only claiming that
the engine will give good service for the length of the warranty period. These are usually
anywhere from 36,000 to 100,000 miles, but rarely more than that. Any major problems
beyond this point and you are on your own, baby! But with today's technology and
manufacturing methods, ANY engine, even the lowliest Daewoo or Kia should be able to give
good service for 100,000 miles. It just takes maintenance. 15,000 mile drain intervals
will allow an 'acceptable' amount of wear and tear that will not show up in any
appreciable way for the length of the warranty. The key here is that there IS unnecessary
wear and tear being introduced with these extended intervals. What I believe and try to
teach my employees and customers is that with a properly broken-in engine, regular
maintenance( 3,000 mile oil changes) and sensible driving habits, it is very possible to
have an engine that basically suffers NO wear and tear for many, many thousands of miles.
The rate of wear can be slowed down to such a degree that it is almost non-existent. My
own personal experience has borne this out time and time again. My '71 429 Mustang had
well over 270,000 miles on the original engine before it was rebuilt. It was still running
fine at that point, no leaking or burning or strange noises, but when I restored the car,
I did not want to put a possibly 'tired' engine back in, only to have to yank it out at
some unplanned future date. When I took it apart, there were no obvious wear problems. My
'79 Lincoln MK-V (400 2-V) has over 340,000 miles on the original engine and runs perfect.
No leaks, knocks or noises. Does not burn oil. And since these engines are known for being
underpowered and thirsty, but certainly NOT known for being durable...this is really a
testament. 3,000 mile oil changes are recommended for the sake of preventing wear and
tear. 15,000 mile oil changes are recommended for the sake of slowing down the wear and
tear. Another consideration for the manufacturers is that the various world governments
are urging them to use less and less oil products whenever possible. The extended drain
intervals are one way to help achieve that. The problem we are all facing is the upcoming
adoption of the new 'GF-4' classification of motor oil. The A.P.I. (American Petroleum
Institute) adopted a classification system to rate the performance of motor oil back in
1961. For gasoline burning engines, it uses letters and the first letter is always an 'S',
signifying that it is for 'Service Stations' (remember those?), assuming that a service
station would only be adding oil to gas-burning engines, since no one ever believed there
would be diesel powered cars at that time. I always found it easier to think of the 'S' as
standing for 'spark ignition', which is how a gas engine works. Anyway, the first letter
is 'S', and the second letter denotes the performance characteristics of the oil through
the use of additives. 'SA' oil was introduced in 1961. Every time the oils required
performance was improved, the second letter was advanced. We are currently at a level of
'SL' for new vehicles sold today. This is a superseding system, meaning that every newer
performance-grade oil can be used in any application that called for a lesser grade.
e.g...today's 'SL' rated oil can be used in a 1995 vehicle that originally called for an
'SG' rated oil. And that older car will derive extra benefits from the newer oil that were
not available when the car was new. However, an older 'SG' rated oil CANNOT be used in
today's cars that require an 'SL' rated oil. By the way, it is highly unlikely that anyone
would ever be able to accidentally find or buy any outdated motor oil considering that
motor oil is a fast moving commodity. It just doesn't sit on the shelves for too long!
This is where the 'GF-4' fiasco
comes in. The government requirements of upcoming oils performance are so stringent, that
simply improving the existing formulations will not be sufficient. The main culprit is
phosphorous. The phosphorous content in motor oil and gasoline is the main contributor to
catalytic converter failure. Today's requirements are that a properly maintained catalytic
converter must perform within its design parameters for a minimum of 50,000 miles, and
they are designed to do so. When this requirement was put into effect (1974), vehicles
lasted an average of 75,000 miles or so. The idea was that as most of the cars converter's
started to fail, they would be heading to the junkyard anyway. With today's vehicles
traveling 200,000 miles regularly, the government feels that the 50,000 mile minimum is
inadequate for long-term protection of the environment. So they raised it to 150,000
miles, beginning with the 2005 model year. The only way that this is possible is for the
phosphorous content in motor oil to be reduced by 50% from what it is currently. The
problem is that it is not possible to refine conventional 'dino' oil using the methods
that are currently in use by refineries and make oil that is sufficient for this. It must
be refined using a different method, (read: expensive) and the big problem is that neither
one of these oils will be compatible with the opposite vehicle's applications. That means
that there will be 2 totally different type of oils for the consumer to choose from. Well,
the oil and vehicle manufacturer's have lobbied hard, and have won a small concession:
Instead of 'GF-4' having 50% of the current levels of phosphorous, current refining
methods can reduce it by about 30% maximum, although it will still cost more. The benefit
however, is that it will be compatible with all standard 'API' as well as 'GF'
classifications. So one type of oil can satisfy both standards. This will only be
short-lived, however, as part of the agreement for the 30% reduction for 2005, is that by
2008 'GF-5' will be the requirement at the original 50% reduction. Whereas the API set the
standards for American vehicles performance, and the European and Japanese counterparts
set their standards, this is the first time that all three of these organizations have
gotten together to set a 'world' standard. This 'world' organization is called 'ILSAC'
(International Lubrication Standardization Acceptance Committee), and you will see this on
the back of almost all current motor oils.
Let's see...blended oils.
The oil companies found out that by
adding a small amount of synthetic base stock to conventional 'dino' stock, they were able
to significantly increase its cold and hot temperature performance. It approaches
full-synthetic performance, but is still a ways away. (Blended oils are almost a definite
with GF-4/5 oils). They are significantly better than regular 'dino'. However, there are
still the trace elements in the 'dino' portion of the oil, and that is what contributes to
sludge formation. For that reason, I do not use blended oils. Blended oils use anywhere
from 2% to 5% synthetic base, depending on viscosity and brand. None are higher than 5%.
(Most erroneously assume it is 50/50). This is a BIG moneymaker for the oil companies.
If your BOSS is overheating, or
just running hot when you are at a 'cruise', there are several things you can do to help
it 'cool off'. My 429 CJ did the same thing. First, I would say use 10W-30 synthetic oil.
Make sure your cooling system is 'up to snuff'. Are you running a 50/50 mix of anti-freeze
and water? Here's why I ask: Anti-freeze is 10 TIMES heavier than water! If you are
running a 50/50 mix, your engine is working 5 times harder just to move the coolant
mixture around than if you were running straight water. Of course, water is extremely
corrosive, so you cannot run straight water, right? Put only enough anti-freeze in your
system that will get it to the lowest temperature you expect it to reach. I live in
Florida, so I only run 8 ounces of anti-freeze in mine. I also added a can of water-pump
lubricant/anti-corrosives (very important!). Lastly, I put in two bottles of redline
'Water Wetter'. This breaks up the surface tension of the water, making it easier for the
engine to move the fluid around. And I use distilled water, which does not have the heavy
mineral content that tap water does. It's only about a buck a gallon at the grocery store.
All of this has resulted in an almost 20 degree drop in temperature, on average. This
really helped me, and a couple of my friends had good results with this also.
The statement that 'synthetic'
lubricants are 'too slippery' in reality does not make any sense: The more slippery a
lubricant is, the better it lubricates (generally speaking).
The reference to the 'lack of
adhesion' from synthetic lubricants is really just a reference to two other functional
properties of the fluid:
1.) 'Viscosity', technically
defined as 'resistance to flow'.
This is a measurement of how easily
a fluid will flow away from a static point. Thicker (higher viscosity) fluids resist this
to a greater degree, so they tend to 'stay put' a little better.
2.) In a gearbox such as a
differential or a manual transmission, the only type of lubrication that you get is a
'Hydro-Static Boundary Layer', which simply means that there is no mechanical or
pressurized mechanism for 'forcing' the lubricant in-between the moving parts. (Other than
the rotating action of the components themselves, which is not anywhere near adequate).
If there were insufficient boundary
layers of lubrication between the gears in a diff or a manual tranny, then the internals
of the gearbox would 'weld' themselves together relatively quickly. That's no good.
So there is a complex group of
additives to address just this predicament, and it is called 'E.P'. The additives that
make up 'E.P.'(which stands for 'extreme pressure', natch!) are developed from zinc,
copper, brass, and other chlorinated solvents. These are commonly referred to as the
'yellow metals', and they possess some very desirable properties. They have a very low
coefficient of friction, and they tend to 'stay-put', which makes them very resistant to
the gearbox's attempts to remove them from contact surfaces through the mechanical
shearing action of the component in question.
Basically, no matter how much
pressure is applied to these additives, they cannot be 'squeezed' out from between the
contact surfaces. This is what allows gear oils to lubricate so effectively without any
type of 'Hydro-Dynamic' protection.
This may bring up a couple of
questions amongst the more curious: First, if 'E.P.' is that good, how come it isn't put
in motor oil to provide even better protection when the engine is first started, or if you
were suddenly to lose oil pressure? Great idea, but it can't work for a couple of reasons;
Mostly because it is not legal for
the additive to be put in motor oil, because chlorine and any chlorinated solvent or
derivative is considered to be a carcinogen, so it can't be in there. The thinking is that
a portion will escape to the atmosphere through normal combustion and exhaust, and the
government says no!
Transmissions and gearboxes are
considered to be 'sealed', so the same rules do not apply.
Also, when a chlorinated compound
is combined with the normal by-products of combustion, it creates an acid that is almost
chemically identical to battery acid! This wreaks havoc with bearings and such. In fact,
before this was illegal, there were chlorine-based additives in motor oil, and they had a
terrible effect on engines. That is why most engines in the 50's and 60's would give good
service for about 60-75,000 miles, and at that point they would be 'smokers' and
'knockers'. Basically, land fill material.
By the way, it is not legal for the
manufacturers to put EP in the oil, but there is no law that says YOU can't put it in your
own oil, if you would ever want to.
EP is the active ingredient (hidden
through clever chemical 'copyrights' on the labels) in many 'engine treatments' available
Specifically, 'Dura-Lube' is loaded
with it. Stay away from that stuff. Or, if you use it, just make sure you change your oil
at least every 3 months regardless of the miles! At least that will keep the harmful acids
from forming so quickly.
Did you ever wonder why 'Slick 50'
or one of the other 'engine treatment' companies didn't market their own brand of motor
oil with their product built right in? Well, because they are not legally allowed to.
Slick 50 tried to get away with
selling oil filters with the product already installed, but they had to pull those from
the market pretty quickly.
So, as long as the gear oil you are
using is of the correct viscosity range, has the correct EP and LS (limited slip)
additives in it, then synthetic is in all respects a better choice than any dino