Is there any interest in doing such a 20W50 run in a car that does not have oil consumption issues (so probably no sticking rings issue) ? Cause I have some 20W50 laying somewhere (probably for more than 20 years) in my garage, and my Barchetta has been neglected for years...
shell ultra 5w40 vs motul 8100 oil control rings
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Hi Lobe,
Pleased you're finding this useful. Just keep reading BITOG and you'll find me stirring up trouble somewhere or other!
In answer to your questions...
I'm not sure what to advise on the Nulon 15W40 only because I've not heard of this company before. I used to know Penrite quite well because they had a really interesting, old school, Technical Manager; but not Nulon. It says it's an SL/CF oil (like the Shell 20W50) but with a quoted TBN of just 6.0, this looks to be a bit on the skinny-side. You do have to be a bit careful with the smaller companies because I have seen some of them play fast and loose with what they claim on the can. If you do decide to use it, same advice as before...don't keep it in too long, don't thrash the engine and keep an eye on the dip stick for early signs of discolouration.
Yes, I would definitely go with the Shell Ultra 5W40. In my experience Shell are an absolute pain in the neck to work for. They want the earth and ideally want you to give it to them for nothing. They also treat suppliers like you're the office bog cleaner! However, because of the weird way they over interpret the rules, they make very good oils which tend to be, if anything, over-formulated. Also the Ultra may well be blended from GTL base oil. I never got to play with GTL stocks when I was strutting my stuff because Shell were always paranoid about giving out samples to suppliers just in case they patented something (as if!). However given the choice between PAO/Group III and GTL, I'd probably opt for GTL.
I would say the Ultra is good for 12,000 miles but I suspect the limiting factor will not be oil degradation but oil loss. I ran my old Daihatsu for several years on a full synthetic 0W20 I threw together in the lab one day. I first ran it out to 9k and it was fine. I then ran it out to 12k and again it was fine. I then ran it out to around 15,500 miles and whilst the oil was still good, 40% of the oil had disappeared out of the sump and presumably down the exhaust pipe (I hadn't bothered to check the dipstick thinking it would be fine like the previous two times). The lesson I took from this is don't trust a low Noack result to keep the oil in the sump over a very long OCI.
Yes I'm old enough to remember THE Bobby Davro but the BobbyDavro I was referring to is a Castrol formulator who posts on BITOG. I'm sure he's a nice enough bloke but he's very corporately 'on message' when he's talking about the slippery stuff. Understandably he's a strong defender of The Engine Test Mentality whereas I'd tear it all down and start again.
Good luck with the trial...
Pleased you're finding this useful. Just keep reading BITOG and you'll find me stirring up trouble somewhere or other!
In answer to your questions...
I'm not sure what to advise on the Nulon 15W40 only because I've not heard of this company before. I used to know Penrite quite well because they had a really interesting, old school, Technical Manager; but not Nulon. It says it's an SL/CF oil (like the Shell 20W50) but with a quoted TBN of just 6.0, this looks to be a bit on the skinny-side. You do have to be a bit careful with the smaller companies because I have seen some of them play fast and loose with what they claim on the can. If you do decide to use it, same advice as before...don't keep it in too long, don't thrash the engine and keep an eye on the dip stick for early signs of discolouration.
Yes, I would definitely go with the Shell Ultra 5W40. In my experience Shell are an absolute pain in the neck to work for. They want the earth and ideally want you to give it to them for nothing. They also treat suppliers like you're the office bog cleaner! However, because of the weird way they over interpret the rules, they make very good oils which tend to be, if anything, over-formulated. Also the Ultra may well be blended from GTL base oil. I never got to play with GTL stocks when I was strutting my stuff because Shell were always paranoid about giving out samples to suppliers just in case they patented something (as if!). However given the choice between PAO/Group III and GTL, I'd probably opt for GTL.
I would say the Ultra is good for 12,000 miles but I suspect the limiting factor will not be oil degradation but oil loss. I ran my old Daihatsu for several years on a full synthetic 0W20 I threw together in the lab one day. I first ran it out to 9k and it was fine. I then ran it out to 12k and again it was fine. I then ran it out to around 15,500 miles and whilst the oil was still good, 40% of the oil had disappeared out of the sump and presumably down the exhaust pipe (I hadn't bothered to check the dipstick thinking it would be fine like the previous two times). The lesson I took from this is don't trust a low Noack result to keep the oil in the sump over a very long OCI.
Yes I'm old enough to remember THE Bobby Davro but the BobbyDavro I was referring to is a Castrol formulator who posts on BITOG. I'm sure he's a nice enough bloke but he's very corporately 'on message' when he's talking about the slippery stuff. Understandably he's a strong defender of The Engine Test Mentality whereas I'd tear it all down and start again.
Good luck with the trial...
Originally Posted By: Popsy
Is there any interest in doing such a 20W50 run in a car that does not have oil consumption issues (so probably no sticking rings issue) ? Cause I have some 20W50 laying somewhere (probably for more than 20 years) in my garage, and my Barchetta has been neglected for years...
Popsy,
If it really is 20 years old then if I were you, I'd take it down the dump and get rid. There will be nothing much wrong with the oil (it's not yogurt and won't go 'off' in that sense). However a 1990's 20W50 like that could easily be SF/CC quality with far too little DI in it. Also, although it's before my time, I've heard all the stories and it's clear there was far too much 'funny stuff' going on in those days throughout the lubricant business. In short, you couldn't rely on an SF/CC oil actually even being SF/CC. The difference in quality between say the 'legit' Shell HX3 20W50 and the stuff sitting in your garage could, in my opinion, be huge.
Is there any interest in doing such a 20W50 run in a car that does not have oil consumption issues (so probably no sticking rings issue) ? Cause I have some 20W50 laying somewhere (probably for more than 20 years) in my garage, and my Barchetta has been neglected for years...
Popsy,
If it really is 20 years old then if I were you, I'd take it down the dump and get rid. There will be nothing much wrong with the oil (it's not yogurt and won't go 'off' in that sense). However a 1990's 20W50 like that could easily be SF/CC quality with far too little DI in it. Also, although it's before my time, I've heard all the stories and it's clear there was far too much 'funny stuff' going on in those days throughout the lubricant business. In short, you couldn't rely on an SF/CC oil actually even being SF/CC. The difference in quality between say the 'legit' Shell HX3 20W50 and the stuff sitting in your garage could, in my opinion, be huge.
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Originally Posted By: SonofJoe
In short, you couldn't rely on an SF/CC oil actually even being SF/CC. The difference in quality between say the 'legit' Shell HX3 20W50 and the stuff sitting in your garage could, in my opinion, be huge.
Sticker says SG/CD, it's a distributor brand (Extralub), don't know who really made it. I think it was bought around 1995-1996. I'll take your advise and recycle it, it wasn't great quality to start with, so if you say oils weren't "reliable" in the nineties, I won't take the chance.
But you still haven't answer to my first question
In short, you couldn't rely on an SF/CC oil actually even being SF/CC. The difference in quality between say the 'legit' Shell HX3 20W50 and the stuff sitting in your garage could, in my opinion, be huge.
Sticker says SG/CD, it's a distributor brand (Extralub), don't know who really made it. I think it was bought around 1995-1996. I'll take your advise and recycle it, it wasn't great quality to start with, so if you say oils weren't "reliable" in the nineties, I won't take the chance.
But you still haven't answer to my first question
Sorry, I missed that bit...
Yes you could run a car with no oil consumption/ring stick issues but I suspect all it would show is that 20W50 mineral is pretty good oil other than for the fact that it's not good for fuel economy & CO2 emissions, for starting in sub -20C conditions and that it needs changing out more quickly than a synthetic.
In most of the advanced countries we've sort of turned out backs towards 20W50 but in the Middle-East, Africa, Latin America and Asia (the hot bits) they are almost the default oil still.
It might be worth mentioning that even though they are rare in the West, oil formulators still put 20W50s through their paces when doing oil development programs. This is because oils are usually developed in blocks rather than singularly. For example you might put together a matrix of tests that simultaneously covers the 10W30, 10W40, 15W40, 15W50 and 20W50 positions. The idea is you test the most severe viscosity grade and 'read-across' the test result to the other, easier viscosity grades without having to actual run further tests. An example might be you test the thinnest oil (the 10W30) on a wear test and if the test passes, you simply assume all the thicker oils would pass it by an even greater margin.
If I misinterpreted what you were asking, just set me straight and I'll have another go tomorrow.
Cheers!
Yes you could run a car with no oil consumption/ring stick issues but I suspect all it would show is that 20W50 mineral is pretty good oil other than for the fact that it's not good for fuel economy & CO2 emissions, for starting in sub -20C conditions and that it needs changing out more quickly than a synthetic.
In most of the advanced countries we've sort of turned out backs towards 20W50 but in the Middle-East, Africa, Latin America and Asia (the hot bits) they are almost the default oil still.
It might be worth mentioning that even though they are rare in the West, oil formulators still put 20W50s through their paces when doing oil development programs. This is because oils are usually developed in blocks rather than singularly. For example you might put together a matrix of tests that simultaneously covers the 10W30, 10W40, 15W40, 15W50 and 20W50 positions. The idea is you test the most severe viscosity grade and 'read-across' the test result to the other, easier viscosity grades without having to actual run further tests. An example might be you test the thinnest oil (the 10W30) on a wear test and if the test passes, you simply assume all the thicker oils would pass it by an even greater margin.
If I misinterpreted what you were asking, just set me straight and I'll have another go tomorrow.
Cheers!
Cheers SonofJoe, thank you for your answer.
My question was somewhat stupid, but I find intriguing all the benefits we could get from "old tech" 20W50 oil, vs more "refined" (pun not intended) thinner, VII loaded oils, like 0W40 or 5W40.
Regarding my car, I found here and there that Fiat was once adamant about its own 10W40 semi-synth oil, and that the semi-synth part was the important part.
I can't seem to find logical reasons to use a 10W40 semi-synth over more "recent" oils, and since I'm a bit bored these days, I just lay here wondering.
Is the 10W part important? How could it be, over a 0W or 5W? Is it the more robust HTHS? Don't think so since recommended oil seem to be very average (Selenia 20K). On engine with worn out cameshaft phase variator (that makes diesel noise at cold start), sure, thicker oil when cold help making this [censored] device shut up, but on perfectly healthy engines?
Is there really a difference between, let's say, a thick "modern" oil like Yacco Galaxie 15W50, and an old school 20W50 like Shell Helix HX3 (I can't seem to find this one locally, 20W50 oils have disappeared from shelves!)? I don't think about the possible longer OCI, better oxidation resistance, etc, but regarding the benefits for the engine. Is it the sulphur in gr I or II?
What about Selenia HPX, that Fiat pushed forward until a few years ago, with miraculous benefits?
Sorry for the off topic, was just digressing.
Edit : that lead us to the most important question, why then are you using 0W20 oil in your car? (I won't take "because it is designed for this type of oils and not 20W50" for an answer, sorry
)
My question was somewhat stupid, but I find intriguing all the benefits we could get from "old tech" 20W50 oil, vs more "refined" (pun not intended) thinner, VII loaded oils, like 0W40 or 5W40.
Regarding my car, I found here and there that Fiat was once adamant about its own 10W40 semi-synth oil, and that the semi-synth part was the important part.
I can't seem to find logical reasons to use a 10W40 semi-synth over more "recent" oils, and since I'm a bit bored these days, I just lay here wondering.
Is the 10W part important? How could it be, over a 0W or 5W? Is it the more robust HTHS? Don't think so since recommended oil seem to be very average (Selenia 20K). On engine with worn out cameshaft phase variator (that makes diesel noise at cold start), sure, thicker oil when cold help making this [censored] device shut up, but on perfectly healthy engines?
Is there really a difference between, let's say, a thick "modern" oil like Yacco Galaxie 15W50, and an old school 20W50 like Shell Helix HX3 (I can't seem to find this one locally, 20W50 oils have disappeared from shelves!)? I don't think about the possible longer OCI, better oxidation resistance, etc, but regarding the benefits for the engine. Is it the sulphur in gr I or II?
What about Selenia HPX, that Fiat pushed forward until a few years ago, with miraculous benefits?
Sorry for the off topic, was just digressing.
Edit : that lead us to the most important question, why then are you using 0W20 oil in your car? (I won't take "because it is designed for this type of oils and not 20W50" for an answer, sorry
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The reason some cars still have 10w40 listed is that 0w40 oils were not available about 20 years ago and it was some time before 5w40 was accepted as OK in terms of shear resistance.
Most good manufacturers have changed the oil specs of their older cars, as have major brand oil companies, although Shell still list OEM spec oils, so for example Shell list Helix 10w40 when Mobil and Castrol list 0w40 for my old 1.9 TDI.
The viscosity of the oil should change with the operating OAT, so if I did 2 oil changes a year, I would use an 0w30 in winter and a 15w40 in summer. Engine load and condition also make a difference, so for a vehicle that had an OEM oil spec of 5w30, I would use an 0 or 5w40 if the block is worn and starting to burn oil.
I can never understand why folks in the US use an 0 or 5w20 once a car is out of warranty, as the only engines I can think of that were OEM spec for Xw20 oils are hybrids.
Most good manufacturers have changed the oil specs of their older cars, as have major brand oil companies, although Shell still list OEM spec oils, so for example Shell list Helix 10w40 when Mobil and Castrol list 0w40 for my old 1.9 TDI.
The viscosity of the oil should change with the operating OAT, so if I did 2 oil changes a year, I would use an 0w30 in winter and a 15w40 in summer. Engine load and condition also make a difference, so for a vehicle that had an OEM oil spec of 5w30, I would use an 0 or 5w40 if the block is worn and starting to burn oil.
I can never understand why folks in the US use an 0 or 5w20 once a car is out of warranty, as the only engines I can think of that were OEM spec for Xw20 oils are hybrids.
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There was a recent thread that educated me a bit about 2-stroke diesels. These spec. straight weight oils because multigrades coke up the exhaust valves with partially burnt viscosity index improvers.
Might the rings in this case also be gummed up with partially burnt viscosity index improvers?
Continuing that line of enquiry, and extending the logic in the above discussion, if a 20/50 is good, might a straight 40 or 50 be better?
In Adelaide I assume you could probably choose your weather appropriately for the experiment, or rig some means of pre-heating the sump.
Re brake fluid as ring groove cleaner, havn't tried it, but I have used it to clean a couple of gummed-up carburettors and it worked pretty well, so I'd say it had potential.
Might the rings in this case also be gummed up with partially burnt viscosity index improvers?
Continuing that line of enquiry, and extending the logic in the above discussion, if a 20/50 is good, might a straight 40 or 50 be better?
In Adelaide I assume you could probably choose your weather appropriately for the experiment, or rig some means of pre-heating the sump.
Re brake fluid as ring groove cleaner, havn't tried it, but I have used it to clean a couple of gummed-up carburettors and it worked pretty well, so I'd say it had potential.
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Originally Posted By: SonofJoe
Assuming the engine starts, let her idle for about 5 minutes. Assuming idling is okay drive her GENTLY around the block a few times just to get the oil circulating around the pistons. Assuming this is problem free, take her for a GENTLE drive. Don't be tempted to do the old Italian Tune-up as it will make bad things happen. You want this oil to remain relatively cool (as close to 100C as possible) and you ideally don't want the turbo kicking in.
Curious.
I realise its a German engine, and might be a bit fragile, but even so, what are these bad things of which you speak, when running it on 20/50, once its warmed up?
Are you just concerned to avoid any oil cooking, or do you fear actual damage?
Assuming the engine starts, let her idle for about 5 minutes. Assuming idling is okay drive her GENTLY around the block a few times just to get the oil circulating around the pistons. Assuming this is problem free, take her for a GENTLE drive. Don't be tempted to do the old Italian Tune-up as it will make bad things happen. You want this oil to remain relatively cool (as close to 100C as possible) and you ideally don't want the turbo kicking in.
Curious.
I realise its a German engine, and might be a bit fragile, but even so, what are these bad things of which you speak, when running it on 20/50, once its warmed up?
Are you just concerned to avoid any oil cooking, or do you fear actual damage?
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This thread is getting interesting!
Regarding Popsy's additional questions...
IMO, there are very definite benefits to using a 20W50 mineral. Wear is negligible, VII loadings are small, Noack volatility tends to be very low and HTHS is always very high. Going back to where this thread started, my gut feel is you would never ever see oil control rings stick if you ran with 20W50 from the get-go. The other advantage, often over looked is that these oils are dirty cheap to manufacture.
However you can't get away from the fact that 20W50's also have some pretty big disadvantages which I flagged up earlier (fuel economy, startability in cold climates and their poor resistance to oxidation. You might also add to the list that OEMs hate all Group I minerals but especially heavy minerals because these oils run counter to their objectives of reducing emissions and increasing OCI. It's no coincidence that over the years we've seen OEMs introduce engine tests that deliberately favour light synthetics and are virtually impossible to pass with heavy minerals. The Sequence IIIG in the US and the Peugeot TU3 test in Europe are two examples of this. Of course, this favouring is never made explicit (the test is always neutral) but all formulators know what game is being played out here.
You might ask why can't we have a full synthetic 20W50 then? Well the answer is you can't easily because the hydrofining/hydrocracking chemical processes that convert mineral stocks to Group IIs & especially Group IIIs tend to destroy the heavy base oils needed to make heavy engine oils (longer hydrocarbons have the greatest propensity to crack when subjected to temperature/pressure/catalyst action). So the more you move in the direction of synthetics, the more you have to shift towards light engine oils otherwise you create an imbalance between supply & demand. You can compensate by adding VII but more VII is generally a bad thing in that it creates more deposits and makes an already bad Noack worse.
In answer to your final question about sulphur, I personally love sulphur in engine oil. It's great! I also love phosphorus. However again the OEMs hate both because of an over done belief that they knacker catalysts. Of course a light synthetic which causes late onset oil ring sticking will have a far greater impact on your catalyst's long-term performance but strangely the OEMs don't seem that bothered about that...
Regarding Popsy's additional questions...
IMO, there are very definite benefits to using a 20W50 mineral. Wear is negligible, VII loadings are small, Noack volatility tends to be very low and HTHS is always very high. Going back to where this thread started, my gut feel is you would never ever see oil control rings stick if you ran with 20W50 from the get-go. The other advantage, often over looked is that these oils are dirty cheap to manufacture.
However you can't get away from the fact that 20W50's also have some pretty big disadvantages which I flagged up earlier (fuel economy, startability in cold climates and their poor resistance to oxidation. You might also add to the list that OEMs hate all Group I minerals but especially heavy minerals because these oils run counter to their objectives of reducing emissions and increasing OCI. It's no coincidence that over the years we've seen OEMs introduce engine tests that deliberately favour light synthetics and are virtually impossible to pass with heavy minerals. The Sequence IIIG in the US and the Peugeot TU3 test in Europe are two examples of this. Of course, this favouring is never made explicit (the test is always neutral) but all formulators know what game is being played out here.
You might ask why can't we have a full synthetic 20W50 then? Well the answer is you can't easily because the hydrofining/hydrocracking chemical processes that convert mineral stocks to Group IIs & especially Group IIIs tend to destroy the heavy base oils needed to make heavy engine oils (longer hydrocarbons have the greatest propensity to crack when subjected to temperature/pressure/catalyst action). So the more you move in the direction of synthetics, the more you have to shift towards light engine oils otherwise you create an imbalance between supply & demand. You can compensate by adding VII but more VII is generally a bad thing in that it creates more deposits and makes an already bad Noack worse.
In answer to your final question about sulphur, I personally love sulphur in engine oil. It's great! I also love phosphorus. However again the OEMs hate both because of an over done belief that they knacker catalysts. Of course a light synthetic which causes late onset oil ring sticking will have a far greater impact on your catalyst's long-term performance but strangely the OEMs don't seem that bothered about that...
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Originally Posted By: Ducked
Originally Posted By: SonofJoe
Assuming the engine starts, let her idle for about 5 minutes. Assuming idling is okay drive her GENTLY around the block a few times just to get the oil circulating around the pistons. Assuming this is problem free, take her for a GENTLE drive. Don't be tempted to do the old Italian Tune-up as it will make bad things happen. You want this oil to remain relatively cool (as close to 100C as possible) and you ideally don't want the turbo kicking in.
Curious.
I realise its a German engine, and might be a bit fragile, but even so, what are these bad things of which you speak, when running it on 20/50, once its warmed up?
Are you just concerned to avoid any oil cooking, or do you fear actual damage?
First off, I'm always naturally cautious and over the years have learnt to expect the unexpected. I'd also be concerned about what the turbo is doing to the oil. Some of the first generation turbos used to run incredibly hot and would literally cook the oil once you turned the engine off. Hence my comments about driving gently to minimise the effect of the turbo. I see this trial as a possible simple and non-invasive way of freeing up a stuck oil ring but obviously you don't want to fix one thing only to create several more problems.
Originally Posted By: SonofJoe
Assuming the engine starts, let her idle for about 5 minutes. Assuming idling is okay drive her GENTLY around the block a few times just to get the oil circulating around the pistons. Assuming this is problem free, take her for a GENTLE drive. Don't be tempted to do the old Italian Tune-up as it will make bad things happen. You want this oil to remain relatively cool (as close to 100C as possible) and you ideally don't want the turbo kicking in.
Curious.
I realise its a German engine, and might be a bit fragile, but even so, what are these bad things of which you speak, when running it on 20/50, once its warmed up?
Are you just concerned to avoid any oil cooking, or do you fear actual damage?
First off, I'm always naturally cautious and over the years have learnt to expect the unexpected. I'd also be concerned about what the turbo is doing to the oil. Some of the first generation turbos used to run incredibly hot and would literally cook the oil once you turned the engine off. Hence my comments about driving gently to minimise the effect of the turbo. I see this trial as a possible simple and non-invasive way of freeing up a stuck oil ring but obviously you don't want to fix one thing only to create several more problems.
Originally Posted By: SonofJoe
This thread is getting interesting!
Regarding Popsy's additional questions...
IMO, there are very definite benefits to using a 20W50 mineral. Wear is negligible, VII loadings are small, Noack volatility tends to be very low and HTHS is always very high. Going back to where this thread started, my gut feel is you would never ever see oil control rings stick if you ran with 20W50 from the get-go. The other advantage, often over looked is that these oils are dirty cheap to manufacture.
However you can't get away from the fact that 20W50's also have some pretty big disadvantages which I flagged up earlier (fuel economy, startability in cold climates and their poor resistance to oxidation. You might also add to the list that OEMs hate all Group I minerals but especially heavy minerals because these oils run counter to their objectives of reducing emissions and increasing OCI. It's no coincidence that over the years we've seen OEMs introduce engine tests that deliberately favour light synthetics and are virtually impossible to pass with heavy minerals. The Sequence IIIG in the US and the Peugeot TU3 test in Europe are two examples of this. Of course, this favouring is never made explicit (the test is always neutral) but all formulators know what game is being played out here.
You might ask why can't we have a full synthetic 20W50 then? Well the answer is you can't easily because the hydrofining/hydrocracking chemical processes that convert mineral stocks to Group IIs & especially Group IIIs tend to destroy the heavy base oils needed to make heavy engine oils (longer hydrocarbons have the greatest propensity to crack when subjected to temperature/pressure/catalyst action). So the more you move in the direction of synthetics, the more you have to shift towards light engine oils otherwise you create an imbalance between supply & demand. You can compensate by adding VII but more VII is generally a bad thing in that it creates more deposits and makes an already bad Noack worse.
In answer to your final question about sulphur, I personally love sulphur in engine oil. It's great! I also love phosphorus. However again the OEMs hate both because of an over done belief that they knacker catalysts. Of course a light synthetic which causes late onset oil ring sticking will have a far greater impact on your catalyst's long-term performance but strangely the OEMs don't seem that bothered about that...
Many 20w50 oils are just cheap thick dino oils that lack additives. The quanity of VI depends on the difference between hot and cold ratings, so is the same as a 10w40 and in reality will make very little difference to the amount in a 5w40.
I thought the issue of Sulphur in US gas had been resolved. It's only an issue in marine diesel in the EU, whereit can damage the liners and rings if the engine spends too much time at low power.
Wear has more to do with oil additives than an oils viscosity unless you do something silly. If you need a thicker oil than a 5w40 for hot desert operations, try Mobil 1 10w60 (There are 2 versions, one an HM oil and the other a race oil) or the HC synthetic version of Amsoil 15w40. They both have good additives and base stocks, but check the API specs.
The best oil for the rings is Shell Ultra (Penn somnething in the US), not some 20w50, although stuck rings are rare and more of a fuel issue.
This thread is getting interesting!
Regarding Popsy's additional questions...
IMO, there are very definite benefits to using a 20W50 mineral. Wear is negligible, VII loadings are small, Noack volatility tends to be very low and HTHS is always very high. Going back to where this thread started, my gut feel is you would never ever see oil control rings stick if you ran with 20W50 from the get-go. The other advantage, often over looked is that these oils are dirty cheap to manufacture.
However you can't get away from the fact that 20W50's also have some pretty big disadvantages which I flagged up earlier (fuel economy, startability in cold climates and their poor resistance to oxidation. You might also add to the list that OEMs hate all Group I minerals but especially heavy minerals because these oils run counter to their objectives of reducing emissions and increasing OCI. It's no coincidence that over the years we've seen OEMs introduce engine tests that deliberately favour light synthetics and are virtually impossible to pass with heavy minerals. The Sequence IIIG in the US and the Peugeot TU3 test in Europe are two examples of this. Of course, this favouring is never made explicit (the test is always neutral) but all formulators know what game is being played out here.
You might ask why can't we have a full synthetic 20W50 then? Well the answer is you can't easily because the hydrofining/hydrocracking chemical processes that convert mineral stocks to Group IIs & especially Group IIIs tend to destroy the heavy base oils needed to make heavy engine oils (longer hydrocarbons have the greatest propensity to crack when subjected to temperature/pressure/catalyst action). So the more you move in the direction of synthetics, the more you have to shift towards light engine oils otherwise you create an imbalance between supply & demand. You can compensate by adding VII but more VII is generally a bad thing in that it creates more deposits and makes an already bad Noack worse.
In answer to your final question about sulphur, I personally love sulphur in engine oil. It's great! I also love phosphorus. However again the OEMs hate both because of an over done belief that they knacker catalysts. Of course a light synthetic which causes late onset oil ring sticking will have a far greater impact on your catalyst's long-term performance but strangely the OEMs don't seem that bothered about that...
Many 20w50 oils are just cheap thick dino oils that lack additives. The quanity of VI depends on the difference between hot and cold ratings, so is the same as a 10w40 and in reality will make very little difference to the amount in a 5w40.
I thought the issue of Sulphur in US gas had been resolved. It's only an issue in marine diesel in the EU, whereit can damage the liners and rings if the engine spends too much time at low power.
Wear has more to do with oil additives than an oils viscosity unless you do something silly. If you need a thicker oil than a 5w40 for hot desert operations, try Mobil 1 10w60 (There are 2 versions, one an HM oil and the other a race oil) or the HC synthetic version of Amsoil 15w40. They both have good additives and base stocks, but check the API specs.
The best oil for the rings is Shell Ultra (Penn somnething in the US), not some 20w50, although stuck rings are rare and more of a fuel issue.
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UltrafanUK,
I'm not sure you've got this right...
These days, most mineral 20W50's are SL/CF and will contain 6-8% DI (depending on who the supplier is). No self-respecting major or national oil company would EVER dare put out a DI-free oil for an API category that's still live.
Regarding VII, assuming you're talking liquid OCP like Lz 7077 (which is standard for these mid-tier oils), you would typically be looking at 5-6% for a full mineral 20W50, 7-8% for 15W40 and about 10-11% for a semi-synthetic 10W40. That's not 'the same' in my book. The amount of VII in a 5W40 depends on a whole raft of factors; base oil-wise whether you're talking Group II/III, all Group III, PAO/ Ester or all GTL and VII-wise whether you're talking OCP or Shellvis or PMA.
Regarding wear, yes wear does depend on additives but if all oils contain the same amount of ZDDP say, not only will the thicker oils generally give better wear performance but the the viscosity grade with the highest aggregate base oil viscosity and the least dependence on VII viscosity give the best wear performance (so that's a win for 20W50 yes?). You might also have wanted to say that mineral SL/CF 20W50s typically contain 1000 ppm Phos, higher than the 800 ppm max you find in a lot of SM/SN synthetics and that SL/CF 20W50's generally have to contain some Moly to pass the Seq. IIIG in a way that most full synthetics don't (so the 20W50 gets a further indirect boost in wear performance).
Finally who told you stuck rings is a fuel issue? You really need to stop listened to the pathetic excuses OEMs trot out when their rubbish engine designs go bad!
I'm not sure you've got this right...
These days, most mineral 20W50's are SL/CF and will contain 6-8% DI (depending on who the supplier is). No self-respecting major or national oil company would EVER dare put out a DI-free oil for an API category that's still live.
Regarding VII, assuming you're talking liquid OCP like Lz 7077 (which is standard for these mid-tier oils), you would typically be looking at 5-6% for a full mineral 20W50, 7-8% for 15W40 and about 10-11% for a semi-synthetic 10W40. That's not 'the same' in my book. The amount of VII in a 5W40 depends on a whole raft of factors; base oil-wise whether you're talking Group II/III, all Group III, PAO/ Ester or all GTL and VII-wise whether you're talking OCP or Shellvis or PMA.
Regarding wear, yes wear does depend on additives but if all oils contain the same amount of ZDDP say, not only will the thicker oils generally give better wear performance but the the viscosity grade with the highest aggregate base oil viscosity and the least dependence on VII viscosity give the best wear performance (so that's a win for 20W50 yes?). You might also have wanted to say that mineral SL/CF 20W50s typically contain 1000 ppm Phos, higher than the 800 ppm max you find in a lot of SM/SN synthetics and that SL/CF 20W50's generally have to contain some Moly to pass the Seq. IIIG in a way that most full synthetics don't (so the 20W50 gets a further indirect boost in wear performance).
Finally who told you stuck rings is a fuel issue? You really need to stop listened to the pathetic excuses OEMs trot out when their rubbish engine designs go bad!
Originally Posted By: SonofJoe
Originally Posted By: Ducked
Originally Posted By: SonofJoe
Assuming the engine starts, let her idle for about 5 minutes. Assuming idling is okay drive her GENTLY around the block a few times just to get the oil circulating around the pistons. Assuming this is problem free, take her for a GENTLE drive. Don't be tempted to do the old Italian Tune-up as it will make bad things happen. You want this oil to remain relatively cool (as close to 100C as possible) and you ideally don't want the turbo kicking in.
Curious.
I realise its a German engine, and might be a bit fragile, but even so, what are these bad things of which you speak, when running it on 20/50, once its warmed up?
Are you just concerned to avoid any oil cooking, or do you fear actual damage?
First off, I'm always naturally cautious and over the years have learnt to expect the unexpected. I'd also be concerned about what the turbo is doing to the oil. Some of the first generation turbos used to run incredibly hot and would literally cook the oil once you turned the engine off. Hence my comments about driving gently to minimise the effect of the turbo. I see this trial as a possible simple and non-invasive way of freeing up a stuck oil ring but obviously you don't want to fix one thing only to create several more problems.
OK, oil cooking then. I'd guess you might be able to minimise that risk by idling it down for a while, which I believe is often recommended for turbos
No reaction to my previous questions, re straight weight oil?
Originally Posted By: Ducked
Originally Posted By: SonofJoe
Assuming the engine starts, let her idle for about 5 minutes. Assuming idling is okay drive her GENTLY around the block a few times just to get the oil circulating around the pistons. Assuming this is problem free, take her for a GENTLE drive. Don't be tempted to do the old Italian Tune-up as it will make bad things happen. You want this oil to remain relatively cool (as close to 100C as possible) and you ideally don't want the turbo kicking in.
Curious.
I realise its a German engine, and might be a bit fragile, but even so, what are these bad things of which you speak, when running it on 20/50, once its warmed up?
Are you just concerned to avoid any oil cooking, or do you fear actual damage?
First off, I'm always naturally cautious and over the years have learnt to expect the unexpected. I'd also be concerned about what the turbo is doing to the oil. Some of the first generation turbos used to run incredibly hot and would literally cook the oil once you turned the engine off. Hence my comments about driving gently to minimise the effect of the turbo. I see this trial as a possible simple and non-invasive way of freeing up a stuck oil ring but obviously you don't want to fix one thing only to create several more problems.
OK, oil cooking then. I'd guess you might be able to minimise that risk by idling it down for a while, which I believe is often recommended for turbos
No reaction to my previous questions, re straight weight oil?
Originally Posted By: Ducked
There was a recent thread that educated me a bit about 2-stroke diesels. These spec. straight weight oils because multigrades coke up the exhaust valves with partially burnt viscosity index improvers.
Might the rings in this case also be gummed up with partially burnt viscosity index improvers?
Continuing that line of enquiry, and extending the logic in the above discussion, if a 20/50 is good, might a straight 40 or 50 be better?
In Adelaide I assume you could probably choose your weather appropriately for the experiment, or rig some means of pre-heating the sump.
Re brake fluid as ring groove cleaner, havn't tried it, but I have used it to clean a couple of gummed-up carburettors and it worked pretty well, so I'd say it had potential.
Ducked,
The link between deposits and VII polymer content tends to be very strong in all diesel engines; both 2-stroke and 4-stroke. For a long time HDDO development had focussed around 15W40 and I suspect this is partly because moving to any other wider cross-grade would have made the job of the DI pack in countering deposit formation borderline impossible.
As regards Lobe's problem, would a straight grade be better for freeing his stuck oil ring, I think the answer could be yes but not necessarily. If you go right to the start of the thread, you'll see I suggested a 20W40 would be better than a 20W50 if he could find one. I said this on the basis that the 20W40 would contain less VII & marginally more heavy base stock. I also figured, a 20W40 PCMO would contain the same level of DI as the 20W50 (it's how matrix based oil programs work). However, had I suggested an SAE 40 oil, I'm not sure I would have had any confidence that the oil would have contained as much additive. Monograde PCMOs aren't mainstream and tend to be something of a lottery in terms of DI treat. I would therefore hesitate in recommending one for Love's trial over the Shell HX3 which for me is much more of a known quantity.
Hope that answers your question...
There was a recent thread that educated me a bit about 2-stroke diesels. These spec. straight weight oils because multigrades coke up the exhaust valves with partially burnt viscosity index improvers.
Might the rings in this case also be gummed up with partially burnt viscosity index improvers?
Continuing that line of enquiry, and extending the logic in the above discussion, if a 20/50 is good, might a straight 40 or 50 be better?
In Adelaide I assume you could probably choose your weather appropriately for the experiment, or rig some means of pre-heating the sump.
Re brake fluid as ring groove cleaner, havn't tried it, but I have used it to clean a couple of gummed-up carburettors and it worked pretty well, so I'd say it had potential.
Ducked,
The link between deposits and VII polymer content tends to be very strong in all diesel engines; both 2-stroke and 4-stroke. For a long time HDDO development had focussed around 15W40 and I suspect this is partly because moving to any other wider cross-grade would have made the job of the DI pack in countering deposit formation borderline impossible.
As regards Lobe's problem, would a straight grade be better for freeing his stuck oil ring, I think the answer could be yes but not necessarily. If you go right to the start of the thread, you'll see I suggested a 20W40 would be better than a 20W50 if he could find one. I said this on the basis that the 20W40 would contain less VII & marginally more heavy base stock. I also figured, a 20W40 PCMO would contain the same level of DI as the 20W50 (it's how matrix based oil programs work). However, had I suggested an SAE 40 oil, I'm not sure I would have had any confidence that the oil would have contained as much additive. Monograde PCMOs aren't mainstream and tend to be something of a lottery in terms of DI treat. I would therefore hesitate in recommending one for Love's trial over the Shell HX3 which for me is much more of a known quantity.
Hope that answers your question...
Thank you for your input Joe, always interesting to read.
Maybe I'll try some 20W50 to see next summer, after all I used some 10W60 for a while so 20W50 can only be ok!
Actually running with very ordinary Motul 5W40...
Maybe I'll try some 20W50 to see next summer, after all I used some 10W60 for a while so 20W50 can only be ok!
Actually running with very ordinary Motul 5W40...
If you compare oils it's best to compare ones in the same API or Acea groups, otherwise there will be differences.
For those readers that don't look at VOA results, or are tempted to use non major brand oils, I would bear in mind that the worst performance supermarket brand oils available are often 20w50's.
Thinking that thicker oils reduce engine wear is just not correct, as you slow down the oil flow around the top end it results in hot spots, shorter HG life and although it might be good for the main bearings, higher upper cylinder wear rates. Most petrol engines are design spec for Xw30's and most disels for Xw40's and you should only use heavier oils if you have a good reason, like badly worn main bearings.
Moving up one grade seems to be OK in most cases IF the oil flow around the top end is good (Use an idle flush etc), BUT moving up 2 grades is defintely not.
Stuck rings have several different causes and in reality are very rare these days. Detonation issues from the use of bad fuel, bad injectors and too long an OCI or using the wrong oil can all cause rings to stick, although corrosion from long periods of storage is probably the main cause.
There have been a few design issues with higher ring pressures and the use of 20 grades in some engines causing the oil control rings to stick.
If you do have an engine prone to the oil scraper rings causing trouble, don't use thick oil as it does not clean as well as the OEM spec oil will, assuming it has the same amount of detergents. The best thing to do is use a good cleaner oil like Mobil 1 0w40, Amsoil or best of all Shell Ultra or the Penn equivalent AND use a major brand idle flush just before changing the oil & filter. If the compression rings are sticking, make sure the timing is correct, use good fuel and make sure the injetors are gum free by using a major brand fuel additive.
Piston soaks do work but are messy and no good for a diesel. If the block is worn they can result in difficult starting issues in winter, due to the resulting compression loss if Carbon deposits were helping the rings to seal.
For those readers that don't look at VOA results, or are tempted to use non major brand oils, I would bear in mind that the worst performance supermarket brand oils available are often 20w50's.
Thinking that thicker oils reduce engine wear is just not correct, as you slow down the oil flow around the top end it results in hot spots, shorter HG life and although it might be good for the main bearings, higher upper cylinder wear rates. Most petrol engines are design spec for Xw30's and most disels for Xw40's and you should only use heavier oils if you have a good reason, like badly worn main bearings.
Moving up one grade seems to be OK in most cases IF the oil flow around the top end is good (Use an idle flush etc), BUT moving up 2 grades is defintely not.
Stuck rings have several different causes and in reality are very rare these days. Detonation issues from the use of bad fuel, bad injectors and too long an OCI or using the wrong oil can all cause rings to stick, although corrosion from long periods of storage is probably the main cause.
There have been a few design issues with higher ring pressures and the use of 20 grades in some engines causing the oil control rings to stick.
If you do have an engine prone to the oil scraper rings causing trouble, don't use thick oil as it does not clean as well as the OEM spec oil will, assuming it has the same amount of detergents. The best thing to do is use a good cleaner oil like Mobil 1 0w40, Amsoil or best of all Shell Ultra or the Penn equivalent AND use a major brand idle flush just before changing the oil & filter. If the compression rings are sticking, make sure the timing is correct, use good fuel and make sure the injetors are gum free by using a major brand fuel additive.
Piston soaks do work but are messy and no good for a diesel. If the block is worn they can result in difficult starting issues in winter, due to the resulting compression loss if Carbon deposits were helping the rings to seal.
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What could possibly be the "best" 20W50 oil currently on the market? Valvoline VR1? Its price is prohibitive for me.
20W50 indeed often look very cheap, and we don't see many voa of 20W50 oils.
I agree top end oil flow is important, especially on cars known to eat camshafts when too thick an oil is used...like mine in fact
But I think SonofJoe is well aware of that, as he stated 20W40 would be better..if only it existed (maybe some Penrite? There was some Shell 20W40 looong time ago, but I haven't seem some in a while).
20W50 indeed often look very cheap, and we don't see many voa of 20W50 oils.
I agree top end oil flow is important, especially on cars known to eat camshafts when too thick an oil is used...like mine in fact
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