15,000 mile synthetic motor oil

The Mobil 1 15K Oil doesn't meet the API energy conserving oil requirements. It is API certified. 15K oil change intervals will not maintain your warranty. If you care about the warranty, I don't see the point in paying extra for a 15K oil and then changing it at 5K intervals. If you are out of warranty, then it is your dime.

From Mobil's web site:

Does the Mobil 1 Extended Performance meet GF-4 specifications? How did the new specification impact the development of the high-endurance product line?

Mobil 1 Extended Performance contains extra performance additives to deliver exceptional performance and protection. This fully synthetic technology is designed specifically for longer service intervals. While it does not meet all the requirements for GF-4, it provides protection of the critical engine parts well beyond conventional engine oils including conventional GF-4 engine oils, and meets all the engine durability and protection requirements for GF-4. Additionally, Mobil 1 Extended Performance oils exceed the requirements of API SL/CF and various ACEA (European) specifications.

Ed

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There seems to be a prevailing opinion that synthetic must be better because it is more expensive. IMHO this is a fallacy. IMHO synthetic is not cost effective.

Most manufacturers state that their engines are designed to operate on commercial mineral oil products and few recommend any extra additives and most discourage their use. Oil functions as both a lubricant and as a way of removing the unwanted products of combustion and wear. Mineral oil does not really wear out but rather becomes contaminated by waste products which can and are often removed by re-refining. Oil change intervals are dependant on the environment and nature of use of the engine. Short trips in cold or moist weather = bad, steady speed and load (highway) use in temperate climate = good. The primary reason to change the oil is to remove the waste products (often acidic or corrosive) which are suspended in it. Many oil and engine manufacturers recommend change intervals determined by time as well as mileage or hours.

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.

The one service condition that I would definitely recommend the use of synthetic oil is extreme cold or arctic weather. This is especially true of gear oil and bearing greases as these components never really warm up even in use and mineral oils do not flow in extreme cold. In this SEVERE cold service I would not be extending engine change intervals and would also recommend a reduced change interval.

Personally I buy whatever premium oil that I find on special and buy a case or more at a time. My application is in two SW1s (240000km & 130000km) in mainly highway use in the mountains of western Canada. I have used oil analysis to check the condition of my used oil and have established a personal change interval of 6000km (3600mi) Normally I just run it until it is down a quart then change the whole works. As a test on the last change of the 240k car I used Wal-Mart Tech 2000, usage increased much more than normal. The first quart was added at 2800km and a second was required at

2200k. This is much faster consumption than usual and I will be going back to premium oil Pennzoil 5w30 which has given me good service and seldom requires addition bettween changes.

Just my .02 YMMV

This is true, but mineral oils are still not as clean as synthetics. This may or may not be a problem, but in Saturn engines it seems to be.

The three Saturns we've had in our household all had 3000 mile oil changes with mineral oil. All had considerable carbon sludge and varnish, like I haven't seen in well-maintained engines for 20 years. None of our cars have had engine problems, except for some oil burning, but inside they looked a mess. And according to Saturn themselves, the oil burning is due to dirty, jammed piston rings.

If synthetic oil had been used, I bet these engines would have been perfectly clean inside -- with no oil burning.

With synthetic, I would have no qualms about the longer oil changes recommended by the oil change lights. The interval would double and so would the cost, with no net cost increase. But I'm sure the engine would be better off. However I agree that 15k mile oil changes are insane with a Saturn. I'd stick to the manufacturer's recommendation, which is typically halved for mineral oil.

My BMWs never had this sludge problem with mineral oil, so that's what I used. There was some yellowing of the metal (varnish) but that was it. I could have used synthetic, but there didn't seem to be any reason to. Not so with the Saturn.

The oil in a Saturn must be exposed to extreme temperatures somewhere, to cause all that carbon buildup. This probably wouldn't happen with a good synthetic. But maybe it does, and frequent oil changes are required anyway to remove it. Thus the oft-heard recommendation to stick with mineral oil for Saturns. Still, if it were my car I'd be using Mobil 1 and going by the oil change lights, not mineral oil every 3k.

Matt O.

Hello Matt,

What are oil change lights?

IMHO sludge is usually caused by operation where the oil is not at full temperature for long enough to expel excess moisture. It often accompanies short trips at low load (or excessive idling) and is often an indicator of a malfunctioning thermostat or the need for a winter front to reduce the airflow through the rad and engine compartment. If this situation continues it will cause ring sticking and the subsequent blow by will also contribute to even more sludge formation especially in the ring grooves.

It is a bit of a chicken or egg situation as sticking rings cause both oil consumption and blow by, and blow by and burnt oil residue causes sticking rings. High oil consumption motivates people to use cheaper oils and to think that since they are adding so much they do not need to change as frequently. High shift points are also a contributor as high piston speeds make oil control more difficult. The high detergent formulas in modern oils have helped a great deal but operating temperature and clean oil is still the key factor. Old oil burns quicker and this is why I tend to just change it all when it is down a quart and never add more than one.

Just my .02

This is one cause, but how do you explain sludge formation when these factors are not present? Saturns do seem to have this problem, even when mostly highway driven. Also, even when these factors are present, synthetic oil seems to prevent sludge.

There's a snowball effect, but sludge/varnish is what causes rings to stick and get the process started. Using a cleaner oil may prevent this.

Matt O.

sticking

sludge

these factors

residue

That, and the rings being poor quality to begin with.

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, 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.

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 shit 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.

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.

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?

Dana Port Kent, NY

2002 Saturn LW300 93 Jeep YJ 90 Jeep XJ Ltd.

---------------

95 Grand Cherokee Ltd. 91 Grand Wagoneer Ltd. 82 Cherokee 4dr 76 Cherokee 2dr

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

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.

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?

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.

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

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

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.

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?

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.

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

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

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.

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?

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.

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

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

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.

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?

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.

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

Regards,

Ed White

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.

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

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.