15,000 mile synthetic motor oil

"Dana Rohleder" > wrote in message
...
> I'm getting into this conversation a little late, but here goes. I have a
> 2002 LW300 (V6), that I use for primarily highway driving. I typically
> change my mineral oil every 3-4K miles. Last oil change I decided to try a
> full synthetic, and will change at the oil change light's recommendation,


what is the oil change light? and how does it work?


> probably every 6k. I did this for one reason - MY TIME. Whether I change
it
> myself or let the dealer do it, I figure I will be wasting half as much of
> my time, which I feel is worth more than the cost difference.
>


Will you use the time saved to better purpose? or will it be wasted working
to pay the cost of time saved? The tax burden on both the service you
purchase and the income you make may consume the value of any time saved and
may even mean a net loss of time vs. DIY, but that is a personal calculation
and another discussion.


> The Saturn service dept. seemed pretty squeamish about me using synthetic,
> saying that with the smaller molecular structure, you can develop leaks
that
> weren't there before. They didn't say not to, but it seemed like they knew
> something that they didn't want to tell me (like 'Don't buy this vehicle,
we
> are going to discontinue them in a couple years and you won't get **** for
> resale!'). I wonder if they were thinking about increased blow-by if the
> ring design tolerances simply aren't up to snuff with synthetics. This
> seemed a little absurd on a motor with 55k on it, so I ignored them and
> switched.
>
> The other day (~2000 miles later) just by accident, I noticed a puff of
oily
> smoke at startup. I started the car with the A/C on which gives it a bit
of
> a jolt when the compressor kicks in, which may have been a contributing
> factor. I am going to keep an eye on the exhaust at startup and my oil
> consumption to see what happens. I would like to stick with the synthetic
> simply to save time and cut down on the use of oil products.
>


IMHO a puff of oil at startup is usually from oil that has leaked past the
valve seals and worn valve guides and not the rings. It may be a factor of
the smaller molecule size or viscosity?


> Europeans have long used 6000k miles plus as their oil change interval
with
> mineral oil and double that with synthetics, likely because of the
expense.
> But to me it makes good sense to not treat any oil like tapwater since it
is
> a limited resource. Instead, we should be insisting on engines that are
> designed for longer oil change intervals, and corresponding lubricant
> designs to complement these engines. After 120 years, they can't find
> something other than fossil oil for lubrication?? It seems like they
should
> be able to run your oil through a machine that reclaims it, cleans it,
adds
> a few additives, then pumps it right back into your oilpan. Then maybe
after
> several cleanings you recycle it as we do now, and replace it. Couldn't an
> oil filter be designed that you replace every 6k and reconditions the oil?
> No, the auto industry instead tries to add DVD players, redundant safety
> systems, and develops vehicles capable of 140-180 mph on the street,
(????)
> all increasing consumption and decreasing efficiency. It's the 60's all
over
> again. Having lived through it, I am bracing for the reality that set in
the
> 70's - waiting in line to buy gas on alternate days based on the last
digit
> of your plate number, having your vacations designed around where & when
you
> can buy gas, 2 ton vehicles with 120 Hp engines with 80 mph top speeds.
>

I understand that we can and do re-refine used oil but that it requires the
use of a cracking tower similar to that used for refining crude. These
re-refineries do exist but are a questionable business proposition due to
the cost of oil collection and the problems of contamination with PCBs etc.
It is currently cheaper to refine new crude but I think this is changing as
the price of both new crude and the disposal of used oil increases. I am
sure that it will become more common as oil runs out and is part of the
discussion of "peak oil". Some large trucking companies mix used (filtered)
oil with diesel fuel and burn it as fuel which is an elegant solution but
can cause increased opacity especially if used in too high a concentration.


> But I'll get off that rant. What I meant to add to the discussion that
> hasn't been brought up is the myriad types and qualities of gasolines out
> there across the country. The discussion seems to be focusing simply on
> engine temp, oil change intervals, and synth vs fossil oils and the
effects
> on sludge/varnish and engine wear. But I would advise that you should also
> look at the gasoline additives and quality - after all, over 6k miles you
> are dumping 250-300 GALLONS of gasoline into the system and thousands of
> cubic feet of polluted/dirty AIR and burning it. I think that has a lot
more
> to do with sludge and oil change intervals than the type of oil you use.
> Think of the crap that is left behind after the gasoline/air/oil mix
> combusts - the oil is there to catch some of it. I think the only way you
> can discuss the issue of oil change intervals is after a thorough
> investigation of gasoline additive/contaminants and how THEY affect both
> types of oil. We can't scrutinize the oils types to the Nth degree with
> regard to quality and additives, then run 250 gallons of gasoline of
unknown
> quality, consistency, and purity through the system, as well as air with a
> myriad of dirt and pollutants and judge the relative merits of fossil vs
> synth. I submit that the useful engine life of American vehicles may
depend
> more on the gasoline and air we run through them than the oils we use to
> lubricate them. Thoughts?
>


Good big picture thinking. IMHE 6000km @ 6.4lt/100km =408lt / 4 = approx
100 USgal. I am under the (anecdotal,uninformed and perhaps faulty)
impression that Canadian gas is better than US gas. I understand that
sulfur is one of the major contaminants in fuel and that it is being reduced
with recent laws in both of our countries and that the manufactures concur
that if we had cleaner fuel that both our engines and our exhausts would be
cleaner and our engines would last longer. Until we do get better gas we
still have the problem of removing the byproducts of the combustion of dirty
fuel and lube oil from our engines in order to maximize their service life
and minimize the consumption of both fuel and oil. The best way to do this
is by driving lighter vehicles and fewer miles but that is also another
discussion.

Just my .02 YMMV

"Dana Rohleder" > wrote in message
...
> I'm getting into this conversation a little late, but here goes. I have a
> 2002 LW300 (V6), that I use for primarily highway driving. I typically
> change my mineral oil every 3-4K miles. Last oil change I decided to try a
> full synthetic, and will change at the oil change light's recommendation,


what is the oil change light? and how does it work?


> probably every 6k. I did this for one reason - MY TIME. Whether I change
it
> myself or let the dealer do it, I figure I will be wasting half as much of
> my time, which I feel is worth more than the cost difference.
>


Will you use the time saved to better purpose? or will it be wasted working
to pay the cost of time saved? The tax burden on both the service you
purchase and the income you make may consume the value of any time saved and
may even mean a net loss of time vs. DIY, but that is a personal calculation
and another discussion.


> The Saturn service dept. seemed pretty squeamish about me using synthetic,
> saying that with the smaller molecular structure, you can develop leaks
that
> weren't there before. They didn't say not to, but it seemed like they knew
> something that they didn't want to tell me (like 'Don't buy this vehicle,
we
> are going to discontinue them in a couple years and you won't get **** for
> resale!'). I wonder if they were thinking about increased blow-by if the
> ring design tolerances simply aren't up to snuff with synthetics. This
> seemed a little absurd on a motor with 55k on it, so I ignored them and
> switched.
>
> The other day (~2000 miles later) just by accident, I noticed a puff of
oily
> smoke at startup. I started the car with the A/C on which gives it a bit
of
> a jolt when the compressor kicks in, which may have been a contributing
> factor. I am going to keep an eye on the exhaust at startup and my oil
> consumption to see what happens. I would like to stick with the synthetic
> simply to save time and cut down on the use of oil products.
>


IMHO a puff of oil at startup is usually from oil that has leaked past the
valve seals and worn valve guides and not the rings. It may be a factor of
the smaller molecule size or viscosity?


> Europeans have long used 6000k miles plus as their oil change interval
with
> mineral oil and double that with synthetics, likely because of the
expense.
> But to me it makes good sense to not treat any oil like tapwater since it
is
> a limited resource. Instead, we should be insisting on engines that are
> designed for longer oil change intervals, and corresponding lubricant
> designs to complement these engines. After 120 years, they can't find
> something other than fossil oil for lubrication?? It seems like they
should
> be able to run your oil through a machine that reclaims it, cleans it,
adds
> a few additives, then pumps it right back into your oilpan. Then maybe
after
> several cleanings you recycle it as we do now, and replace it. Couldn't an
> oil filter be designed that you replace every 6k and reconditions the oil?
> No, the auto industry instead tries to add DVD players, redundant safety
> systems, and develops vehicles capable of 140-180 mph on the street,
(????)
> all increasing consumption and decreasing efficiency. It's the 60's all
over
> again. Having lived through it, I am bracing for the reality that set in
the
> 70's - waiting in line to buy gas on alternate days based on the last
digit
> of your plate number, having your vacations designed around where & when
you
> can buy gas, 2 ton vehicles with 120 Hp engines with 80 mph top speeds.
>

I understand that we can and do re-refine used oil but that it requires the
use of a cracking tower similar to that used for refining crude. These
re-refineries do exist but are a questionable business proposition due to
the cost of oil collection and the problems of contamination with PCBs etc.
It is currently cheaper to refine new crude but I think this is changing as
the price of both new crude and the disposal of used oil increases. I am
sure that it will become more common as oil runs out and is part of the
discussion of "peak oil". Some large trucking companies mix used (filtered)
oil with diesel fuel and burn it as fuel which is an elegant solution but
can cause increased opacity especially if used in too high a concentration.


> But I'll get off that rant. What I meant to add to the discussion that
> hasn't been brought up is the myriad types and qualities of gasolines out
> there across the country. The discussion seems to be focusing simply on
> engine temp, oil change intervals, and synth vs fossil oils and the
effects
> on sludge/varnish and engine wear. But I would advise that you should also
> look at the gasoline additives and quality - after all, over 6k miles you
> are dumping 250-300 GALLONS of gasoline into the system and thousands of
> cubic feet of polluted/dirty AIR and burning it. I think that has a lot
more
> to do with sludge and oil change intervals than the type of oil you use.
> Think of the crap that is left behind after the gasoline/air/oil mix
> combusts - the oil is there to catch some of it. I think the only way you
> can discuss the issue of oil change intervals is after a thorough
> investigation of gasoline additive/contaminants and how THEY affect both
> types of oil. We can't scrutinize the oils types to the Nth degree with
> regard to quality and additives, then run 250 gallons of gasoline of
unknown
> quality, consistency, and purity through the system, as well as air with a
> myriad of dirt and pollutants and judge the relative merits of fossil vs
> synth. I submit that the useful engine life of American vehicles may
depend
> more on the gasoline and air we run through them than the oils we use to
> lubricate them. Thoughts?
>


Good big picture thinking. IMHE 6000km @ 6.4lt/100km =408lt / 4 = approx
100 USgal. I am under the (anecdotal,uninformed and perhaps faulty)
impression that Canadian gas is better than US gas. I understand that
sulfur is one of the major contaminants in fuel and that it is being reduced
with recent laws in both of our countries and that the manufactures concur
that if we had cleaner fuel that both our engines and our exhausts would be
cleaner and our engines would last longer. Until we do get better gas we
still have the problem of removing the byproducts of the combustion of dirty
fuel and lube oil from our engines in order to maximize their service life
and minimize the consumption of both fuel and oil. The best way to do this
is by driving lighter vehicles and fewer miles but that is also another
discussion.

Just my .02 YMMV

private wrote:

> what is the oil change light? and how does it work?

http://service.gm.com/gmtechlink/arcv_pdf/3_00_e.pdf

Regards,

Ed White

"private" > wrote in message
news:Qxnle.1488235$8l.621268@pd7tw1no...

> Modern mineral oils are much better than oils of twenty years ago and have
a
> high concentration of synthetic and detergent additives. IMHE premium
> mineral oils do give longer periods between both additions and changes.
>
> Synthetic oil MAY be better for EXTREME high temperature use but I have no
> experience, and would suggest that for most applications a quality mineral
> oil of the CORRECT viscosity will provide good service.

It's also good for extreme low temperature use, since it flows better at
start-up.

The myth is that you can go longer between oil changes with synthetic. Both
synthetic and petroleum based oil will lubricate far beyond the typical 5000
or 7500 mile oil change interval. But as you stated, the reason for more
frequent changes is contamination of the oil, and the synthetic gets just as
contaminated as the petroleum based oil (you could solve this with a bypass
filter, but this is done only on big engines that use several gallons of
oil). The oil also becomes acidic, and unlike big engines, the use of acid
neutralizers in an engine that only has 4-5 quarts of oil, is just not done.

On older Saturns, with 3000 mile oil changes, there is really no reason to
use synthetic oil. These engines are notorious oil burners, and the reason
for the oil burning would not be solved by synthetic oil. With the poor
quality rings, you would never want to switch to synthetic if you've been
running petroleum based oil for any length of time.

Avoid non-API certified synthetics such as Amsoil (except for their XL-7500
line. The problem with the non-API certified synthetics is that they contain
too much phosphorus (in the form of the additive ZDDP (Zinc Dialkyl
Dithiophosphates)). The API has limited the amount of phosphorus because
phosphorus shortens the life of the catalytic converter. These oils are fine
for snowmobiles, motorcycles, and older cars that don't have a catalytic
converter, and the extra ZDDP does provide additional wear protection.
Unfortunately, the marketers of some the non-certified oils do not
explicitly and honestly state the reason for the lack of API certification.
You can check the status of API certification on the API web site. Be
certain to go not just by the manufacturer name but by the actual product as
well. This is because a manufacturer will sometimes have both certified and
non-certified products.

Thanks for the link, it is a clear explanation of the oil change light and
also has some good information on the original topic. It also lead me to
this site that seems to have lots more good stuff.
http://www.gmtechlink.com/

Since the light is controlled by a program, it will be at best a guestimate.
It will only be as good as the usage model and sophistication of the
programming algorithm. I would think that it is much better than nothing
and since it is software driven does not cost much to include. I would
speculate that it cannot be relied on to take engine condition and driving
style into account. I would also think that the model is more applicable to
an engine during the warrantee period and not as good for older engines. I
would also suspect that it does not adjust for variables like air intake
humidity and temperature. An engine with a good thermostat would indicate
to the computer that it was warm but the intake air could still be very cold
which could be causing poor atomization and incomplete combustion. I would
hope that the programming would recognize excessive idling but would doubt
that it is sophisticated enough to recognize high shift points, jackrabbit
starts and shall we say spirited driving styles that IMHO are the cause of
much of the complaints of poor ring wear and subsequent oil contamination
caused by increased blowby.

Just my .02 YMMV

"C. E. White" > wrote in message
...
>
>
> private wrote:
>
> > what is the oil change light? and how does it work?
>
> http://service.gm.com/gmtechlink/arcv_pdf/3_00_e.pdf
>
> Regards,
>
> Ed White

Everything I've read from Saturn and in a Chilton's manual say you should
not use any fuel additives in a Saturn because you will burn out sensors.