Synthetic oil
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I noticed a lot of improvements have been made to the lower viscocities dinos like 5w-20 and 10w-30..not so for 20w-50 which still is real old school sludge varnish prone dino prevalent in 3rd world countries.
I have much better results with grp3 and 4 synths in my engine. Heck even with M1 0w-40 the engine is pretty silent.
I have much better results with grp3 and 4 synths in my engine. Heck even with M1 0w-40 the engine is pretty silent.
Originally Posted By: NHRATA
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
As you can see from the responses, BITOG is probably the last place that you'll get a consensus for your question.
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
As you can see from the responses, BITOG is probably the last place that you'll get a consensus for your question.
Originally Posted By: NHRATA
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
For really cold places, certainly. For places less extreme, maybe. I have always changed my own oil but don't have the time or energy to change it every 3k miles. For me, synthetic is the easy button allowing me to comfortably change it every 10k. Note, my engine is known to be easy on oil...
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
For really cold places, certainly. For places less extreme, maybe. I have always changed my own oil but don't have the time or energy to change it every 3k miles. For me, synthetic is the easy button allowing me to comfortably change it every 10k. Note, my engine is known to be easy on oil...
Originally Posted By: bobbydavro
Originally Posted By: UltrafanUK
Originally Posted By: NHRATA
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
If by synthetic you mean HC (Hydro Crack), then there is almost no difference between a good major brand conventional like Castrol GTX and an HC synthetic like Castrol Edge, IF you change every 3000 miles AND don't live in the Artic where you really do need an 0wXX oil.
Now if you are talking about the real McCoy full synthetics, like Liqui Moly Synthoil or Shell Ultra, then the only difference is that they do keep the top end a fraction cleaner and resist high temp shearing slightly better. In reality the latter is only important in turbo charged engines.
The most important thing about any engine oil that is not pushed to the extremes of an extended OCI, or fried in a hot turbo at redline RPM, is the quality of the additives included in the oil.
Why would a group 4 mean a cleaner cylinder head?
Turbos aren't really an issue anymore. Piston rings run hotter
Group 4 or group 3 plus (Gas to liquids technology) base oils are less contaminated and act as natural solvents. To give you a practical example, Ultra 0w40 will keep the rings cleaner than M1 0w40 or Edge 0w40 (The test data was published by Shell and none of the major players could deny it). A true group 4 synthetic seems to produce the same results, even though HC synthetics like M1 contain more detergents.
My own UOA results indicate there is no difference between the performance of Shell Ultra 5w40 and Liqui Moly 5w40, so I just use the former as it's cheaper.
Turbo temps vary from engine to engine, with Porsch and Subaru as known hot runners that will chew up a conventional oil in high temp shearing terms if the car is driven hard. The turbo is of more interest than the rings, because it will fail before the main block if the oil feed line suffers from varnish or the oil itself degrades. That's why I'm real fussy about oil type for a turbo charged engine, but not too concerned if it is a normally aspirated one, although some VVT (variable valve timing or cam phaser) units are also rather sensitive in oil terms.
I would point out to the 3K OCI addicts, that doing too short an OCI can cause more wear than one based on a series of UOA results. My own TDI has to suffer a lot of short tripping, so I guessed at an intial 10K km oil change with 20K km oil and filter changes (The recommended max). I was very surprised to find out that the Fe and Al figures were far better per km with a longer 17K km oil change. So I'm now doing 20K km oil and filter changes.
The reasons why longer oil change intervals are often better are rather complex, as they relate to the interaction of new oil with old residual oil, in addition to changes in oil filter efficiency. To confuse matters, changing the oil type too often between conventional and full synthetic is not entirely good news either.
Originally Posted By: UltrafanUK
Originally Posted By: NHRATA
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
If by synthetic you mean HC (Hydro Crack), then there is almost no difference between a good major brand conventional like Castrol GTX and an HC synthetic like Castrol Edge, IF you change every 3000 miles AND don't live in the Artic where you really do need an 0wXX oil.
Now if you are talking about the real McCoy full synthetics, like Liqui Moly Synthoil or Shell Ultra, then the only difference is that they do keep the top end a fraction cleaner and resist high temp shearing slightly better. In reality the latter is only important in turbo charged engines.
The most important thing about any engine oil that is not pushed to the extremes of an extended OCI, or fried in a hot turbo at redline RPM, is the quality of the additives included in the oil.
Why would a group 4 mean a cleaner cylinder head?
Turbos aren't really an issue anymore. Piston rings run hotter
Group 4 or group 3 plus (Gas to liquids technology) base oils are less contaminated and act as natural solvents. To give you a practical example, Ultra 0w40 will keep the rings cleaner than M1 0w40 or Edge 0w40 (The test data was published by Shell and none of the major players could deny it). A true group 4 synthetic seems to produce the same results, even though HC synthetics like M1 contain more detergents.
My own UOA results indicate there is no difference between the performance of Shell Ultra 5w40 and Liqui Moly 5w40, so I just use the former as it's cheaper.
Turbo temps vary from engine to engine, with Porsch and Subaru as known hot runners that will chew up a conventional oil in high temp shearing terms if the car is driven hard. The turbo is of more interest than the rings, because it will fail before the main block if the oil feed line suffers from varnish or the oil itself degrades. That's why I'm real fussy about oil type for a turbo charged engine, but not too concerned if it is a normally aspirated one, although some VVT (variable valve timing or cam phaser) units are also rather sensitive in oil terms.
I would point out to the 3K OCI addicts, that doing too short an OCI can cause more wear than one based on a series of UOA results. My own TDI has to suffer a lot of short tripping, so I guessed at an intial 10K km oil change with 20K km oil and filter changes (The recommended max). I was very surprised to find out that the Fe and Al figures were far better per km with a longer 17K km oil change. So I'm now doing 20K km oil and filter changes.
The reasons why longer oil change intervals are often better are rather complex, as they relate to the interaction of new oil with old residual oil, in addition to changes in oil filter efficiency. To confuse matters, changing the oil type too often between conventional and full synthetic is not entirely good news either.
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Absolute rubbish I'm afraid. Contamination is not linked to solvency. Polarity is though and PAO are the least solvent base oils our there. Often the ester you see in marketing claims is only there to get the solubility up. Group 1 are very soluble and a bit of it in s formulation can help with cleanliness.
You are also probably confusing contamination with residual wax and sulphur.
Turbo shear is insignificant. And I've seen plenty of group 3 oils perform as well as /better than PAO in test that look at turbo feed deposits. Additive and VII have just as an important effect on compressor deposits (blow by induced)
There is already enough miss information on ther Internet. Don't add to it with regurgitation
Agreed on too short drains but you don't want to overdo it and I'm doubtful if your UOA is conclusive. Your oil filter is probably getting dirty on longer drains and filtering a out wear metals. Plus on a diesel you will get biodiesel contamination diluting the oil (and the wear metal count)
You are also probably confusing contamination with residual wax and sulphur.
Turbo shear is insignificant. And I've seen plenty of group 3 oils perform as well as /better than PAO in test that look at turbo feed deposits. Additive and VII have just as an important effect on compressor deposits (blow by induced)
There is already enough miss information on ther Internet. Don't add to it with regurgitation
Agreed on too short drains but you don't want to overdo it and I'm doubtful if your UOA is conclusive. Your oil filter is probably getting dirty on longer drains and filtering a out wear metals. Plus on a diesel you will get biodiesel contamination diluting the oil (and the wear metal count)
Oh and which data are you referring to about keeping rings cleaner ?
All these posts, and not one mention of the additive package, which makes up 20-25% of any motor oil. Everyone gives all kinds of credit to the base oil only. Even the best synthetic base oil without a good add pack will destroy an engine. I split the middle and use syn blends. Best of both worlds, with a great add pack.
Originally Posted By: NHRATA
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
It is important to follow the manufacturer's recommendations in the manual in terms of oil grade and interval. A car that requires an 0w20 will require at least a synthetic blend as there is no conventional 0w20 oil. A modern GM vehicle will require a Dexos oil, etc. It should be noted however that the use of a synthetic over conventional oil where not called for in the manual will not allow you to increase the interval in the eyes of the manufacturer. Furthermore, Oil Life Monitors in many modern vehicles are equipped based on the manufacturers recommendations. Therefore if conventional oil is called for in the manual and you use a synthetic oil, the system will not in any way increase in the interval.
Simply put, follow your owners manual guidelines for long engine life. There is no reason to overthink this.
There are synthetic oils marketed for protection up to 15,000 miles such as Mobil 1 EP, however the fine print says to follow your vehicles owner manual for oil change intervals.
If UOAs have showed me anything, it is that conventional oils are just as capable as synthetic oils for long oil change intervals. You cannot blanket statement and say that a synthetic oil will perform much better over a longer interval. There have been UOAs posted here on conventional oil run longer than many synthetic oils that performed.
All of that being said, if it were my vehicle and money and I was doing 3k mile OCIs I would not spend the extra money on a synthetic oil unless my owners manual required it. In this instance I would run the cheapest conventional oil I could that met my vehicle's requirements.
Is synthetic oil basically just for extended oil change intervals? Are there any real benefits to using a synthetic over a good conventional or synthetic blend if you plan on changing your oil at 3000 miles?
It is important to follow the manufacturer's recommendations in the manual in terms of oil grade and interval. A car that requires an 0w20 will require at least a synthetic blend as there is no conventional 0w20 oil. A modern GM vehicle will require a Dexos oil, etc. It should be noted however that the use of a synthetic over conventional oil where not called for in the manual will not allow you to increase the interval in the eyes of the manufacturer. Furthermore, Oil Life Monitors in many modern vehicles are equipped based on the manufacturers recommendations. Therefore if conventional oil is called for in the manual and you use a synthetic oil, the system will not in any way increase in the interval.
Simply put, follow your owners manual guidelines for long engine life. There is no reason to overthink this.
There are synthetic oils marketed for protection up to 15,000 miles such as Mobil 1 EP, however the fine print says to follow your vehicles owner manual for oil change intervals.
If UOAs have showed me anything, it is that conventional oils are just as capable as synthetic oils for long oil change intervals. You cannot blanket statement and say that a synthetic oil will perform much better over a longer interval. There have been UOAs posted here on conventional oil run longer than many synthetic oils that performed.
All of that being said, if it were my vehicle and money and I was doing 3k mile OCIs I would not spend the extra money on a synthetic oil unless my owners manual required it. In this instance I would run the cheapest conventional oil I could that met my vehicle's requirements.
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There have been enough 10Kish UOAs posted over the years where the group II oil had thickened (maybe not out of grade but significantly thicker than when it went in) and the group IIIs like M1/PP were still modestly thinner than when they went in.
I'm an old Navy jet mech and started using Mobil 1 back in the late 70s when it was about the only game in town. I believed that synthetics were so good they would virtually stop engine wear. Fast forward a bunch of years and I found that is not necessarily true. I had been running synthetics in my 08 Jeep Wrangler with about 5k mile changes. Not long ago I tried a run of conventional PYB. I was surprised that UOAs showed excellent protection equal to if not better than the synthetic oil. Some wear numbers were better.
My last run of PYB went through winter with plenty of sub zero starts. A UOA showed it still did a great job in the Jeep.
My last run of PYB went through winter with plenty of sub zero starts. A UOA showed it still did a great job in the Jeep.
Switching my free junkyard 350 Oldsmobile to synthetic when I got it 10 years ago to put in my rust-free 84 cutlass might make the difference between having to overhaul the engine finally this decade, or maybe not for another 30 years / 300k miles +.
For most vehicles that will be in the junkyard in the next 20 years it's probably not worth using synthetic. But if your car doesn't see any road salt and might last another 50+ years, synthetic is the way to go IMO.
For most vehicles that will be in the junkyard in the next 20 years it's probably not worth using synthetic. But if your car doesn't see any road salt and might last another 50+ years, synthetic is the way to go IMO.
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