Diesel 15w40 oil installed of 5w30 Gas
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Originally Posted By: ShawnTRD
Been seeing a lot more poeple using 15w40 diesel oil in the gas engines that as spec. for 5w30. Whats the story on this.
Where have you been seeing this ??.....
Been seeing a lot more poeple using 15w40 diesel oil in the gas engines that as spec. for 5w30. Whats the story on this.
Where have you been seeing this ??.....
My engine specs 5w-30, and I run 15w-40 when it's warm enough.
Makes me feel better. Warm and fuzzy effect, I suppose. (The 40-wt, I mean... the 15w doesn't make a [censored] of difference to me when it's 45+ degrees at the coldest.)
I'll stop if it's proven to cause damage.
Makes me feel better. Warm and fuzzy effect, I suppose. (The 40-wt, I mean... the 15w doesn't make a [censored] of difference to me when it's 45+ degrees at the coldest.)
I'll stop if it's proven to cause damage.
The problem with the diesel oils is that, even if they have the gasoline specification -- such as SM -- in addition to the diesel specification -- such as CJ-4 -- they are not required by API to meet all performance requirements of the gasoline category (SM). This means you have a much higher catalytic-converter poisoning and spark-plug fouling concentrations of additives.
Therefore, avoid diesel engine oils, even if they have the SM/SN certification, as the API requirements to meet these certifications are far more lax than for gasoline-engine oils.
The bottom line: Always use an oil with the API "Starburst" symbol in the front label on the bottle for best protection for gasoline engines. It's very simple.
(Exceptions would be 1970s or earlier cars or race engines, which might require xW-40 or xW-50 weights. Even in these cases, it's a good idea to avoid C [C for commercial {diesel} as in CJ-4 etc.] oils, which might have additives bad for gasoline engines.)
Therefore, avoid diesel engine oils, even if they have the SM/SN certification, as the API requirements to meet these certifications are far more lax than for gasoline-engine oils.
The bottom line: Always use an oil with the API "Starburst" symbol in the front label on the bottle for best protection for gasoline engines. It's very simple.
(Exceptions would be 1970s or earlier cars or race engines, which might require xW-40 or xW-50 weights. Even in these cases, it's a good idea to avoid C [C for commercial {diesel} as in CJ-4 etc.] oils, which might have additives bad for gasoline engines.)
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Originally Posted By: Gokhan
The problem with the diesel oils is that, even if they have the gasoline specification -- such as SM -- in addition to the diesel specification -- such as CJ-4 -- they are not required by API to meet all performance requirements of the gasoline category (SM). This means you have a much higher catalytic-converter poisoning and spark-plug fouling concentrations of additives.
Therefore, avoid diesel engine oils, even if they have the SM/SN certification, as the API requirements to meet these certifications are far more lax than for gasoline-engine oils.
The bottom line: Always use an oil with the API "Starburst" symbol in the front label on the bottle for best protection for gasoline engines. It's very simple.
(Exceptions would be 1970s or earlier cars or race engines, which might require xW-40 or xW-50 weights. Even in these cases, it's a good idea to avoid C [C for commercial {diesel} as in CJ-4 etc.] oils, which might have additives bad for gasoline engines.)
Realistically speaking, unless your engine was drinking oil like a drunken sailor would his beer, it's not going to poison a cat or foul a plug. I'm not saying it's use in a gas engine is either good or bad, just understand that in the overwhelming vast majority of cars, it's a non issue.
The problem with the diesel oils is that, even if they have the gasoline specification -- such as SM -- in addition to the diesel specification -- such as CJ-4 -- they are not required by API to meet all performance requirements of the gasoline category (SM). This means you have a much higher catalytic-converter poisoning and spark-plug fouling concentrations of additives.
Therefore, avoid diesel engine oils, even if they have the SM/SN certification, as the API requirements to meet these certifications are far more lax than for gasoline-engine oils.
The bottom line: Always use an oil with the API "Starburst" symbol in the front label on the bottle for best protection for gasoline engines. It's very simple.
(Exceptions would be 1970s or earlier cars or race engines, which might require xW-40 or xW-50 weights. Even in these cases, it's a good idea to avoid C [C for commercial {diesel} as in CJ-4 etc.] oils, which might have additives bad for gasoline engines.)
Realistically speaking, unless your engine was drinking oil like a drunken sailor would his beer, it's not going to poison a cat or foul a plug. I'm not saying it's use in a gas engine is either good or bad, just understand that in the overwhelming vast majority of cars, it's a non issue.
Originally Posted By: Gokhan
Therefore, avoid diesel engine oils, even if they have the SM/SN certification, as the API requirements to meet these certifications are far more lax than for gasoline-engine oils.
The bottom line: Always use an oil with the API "Starburst" symbol in the front label on the bottle for best protection for gasoline engines. It's very simple.
Don't confuse the GF-4/GF-5 versus SM/SN issue. The Starburst symbol isn't simply conferred by meeting SM or SN.
Technically speaking, one should see what the manual recommends. If the manual only requires SM and specifies a wide range of viscosities, any SM, including an HDEO appropriate for the ambient, would work.
Take for example, my Audi 200 Turbo. It requires SJ or better. It doesn't speak of energy conserving or anything else, just SJ or better and a list of viscosities. 15w-40 is recommended almost all temperatures, except extreme cold. Last time I checked, most 15w-40 grades were HDEOs. So, to follow my manufacturer's recommendation, I pretty much have to go the HDEO route.
Most vehicles, however, recommend a combination of SM and energy conserving, which means an SM/GL-4 or SN/GL-5 oil. It's not that an SM HDEO doesn't meet the same SM specs as PCMO, it's that SM HDEO doesn't meet the ILSAC specifications, and doesn't claim to.
If a car requires the combination of the current API and ILSAC certifications, it should be obvious that an HDEO won't meet those specifications, simply by reading the bottle, and because HDEOs don't tend to come in a 5w-30 or 5w-20, which are the most commonly recommended grades in North America.
Therefore, avoid diesel engine oils, even if they have the SM/SN certification, as the API requirements to meet these certifications are far more lax than for gasoline-engine oils.
The bottom line: Always use an oil with the API "Starburst" symbol in the front label on the bottle for best protection for gasoline engines. It's very simple.
Don't confuse the GF-4/GF-5 versus SM/SN issue. The Starburst symbol isn't simply conferred by meeting SM or SN.
Technically speaking, one should see what the manual recommends. If the manual only requires SM and specifies a wide range of viscosities, any SM, including an HDEO appropriate for the ambient, would work.
Take for example, my Audi 200 Turbo. It requires SJ or better. It doesn't speak of energy conserving or anything else, just SJ or better and a list of viscosities. 15w-40 is recommended almost all temperatures, except extreme cold. Last time I checked, most 15w-40 grades were HDEOs. So, to follow my manufacturer's recommendation, I pretty much have to go the HDEO route.
Most vehicles, however, recommend a combination of SM and energy conserving, which means an SM/GL-4 or SN/GL-5 oil. It's not that an SM HDEO doesn't meet the same SM specs as PCMO, it's that SM HDEO doesn't meet the ILSAC specifications, and doesn't claim to.
If a car requires the combination of the current API and ILSAC certifications, it should be obvious that an HDEO won't meet those specifications, simply by reading the bottle, and because HDEOs don't tend to come in a 5w-30 or 5w-20, which are the most commonly recommended grades in North America.
You missed the important point that I was trying to make. Even though the C oils (what you like to call "HDEO") claim to meet SM (not GF-4, SM only), in reality they do not. The claim that they meet SM is only for fleet-owner purposes. The SM requirements (again, not GF-4) are much more lax for C oils than for S oils. This means that Cx/Sy (such as CJ-4/SM) oils don't offer the same protection for the gasoline engines as the Sy (such as SM) oils.
See this reading on API's Web site, especially the footnotes on Page 62 (66 in PDF file).
So, if you need higher viscosity grades, stay away from the Cx/Sy oils and stick with Sy oils. Neither a CJ-4/SM 10W-40 nor an SM 10W-40 meet GF-4 but if an oil doesn't have the Cx prefix (such as an SM-only 10W-40), it's required to fully meet the Sx specifications, without the footnotes in the link above.
See this reading on API's Web site, especially the footnotes on Page 62 (66 in PDF file).
So, if you need higher viscosity grades, stay away from the Cx/Sy oils and stick with Sy oils. Neither a CJ-4/SM 10W-40 nor an SM 10W-40 meet GF-4 but if an oil doesn't have the Cx prefix (such as an SM-only 10W-40), it's required to fully meet the Sx specifications, without the footnotes in the link above.
However, Gokhan, that applies if the Sx is before the Cx and there is no API certification mark. Many of the HDEOs that I've used do have the certification mark. As for the positioning of the Sx in relation to the Cx, there is a surprising mix out there. I've seen bottles of 10w-40 PCMO with the C ahead of the S, and it still has the API certification mark. So, according to that footnote, the rules would still apply, had other conditions not applied - i.e exemption from P limits because it's 10w-40 and not 0w-20, 5w-20, 0w-30, 5w-30, or 10w-30, to which those limits apply.
An SM 10w-40 has a few different rules than would an SM 5w-20, and there are even certain differences for SM 10w-30. That's not the only issue. So, no, the SM only 10w-40 does have different requirements than SM 5w-20, from the document you linked. Also, I don't know of any new North American vehicle (or any for many years) that call for a 10w-40.
I haven't seen any newer car manual out there that simply recommended SM certified oil. There is always something else, like GF-4 or the call for the Starburst symbol, which is, actually a GF-4 or GF-5 ILSAC rating, along with a preferred or required viscosity. So, essentially, assuming there aren't proprietary specifications, a newer vehicle will require SM/GF-4 or better.
It's not going to just call for SM and ignore everything else. In the past, sure, but for the past several years, manuals have called for more than one specification, with the API and ILSAC markings both being required as a minimum.
Anyone who would buy the newest Esso XD-3 5w-30 HDEO and put it in a new engine when it doesn't meet the ILSAC specifications could do themselves a disservice if warranty ever became an issue. It simply isn't speced for the vehicle. However, my Audi gets HDEO in the summer, since that is essentially all that's available in the preferred weight.
Besides, the bigger issue is going way out of spec without a carefully researched reason. It's not appropriate to run an SB 5w-30 in a GM vehicle built say in the last 15 years, even though the viscosity would be correct. It's also not correct to run an SM 20w-50 in a the same vehicle, even though the SM might exceed the API standard contemporary to the manufacture.
In some ways, we're making a similar point. We're both saying not to look at one specification in isolation and choose based on that. If one follows the recommendations of one's manual, one will get the correct oil, and it very likely won't be an HDEO for a gasoline engine, particularly if the Starburst symbol is called for in the manual.
There is nothing wrong with HDEOs (and plenty that is right) for people with vehicles of a certain vintage and certain requirements. I'm not going to find a PCMO 15w-40 for my Audi. For my old F-150, I'm not going to find a higher content of ZDDP outside HDEOs, unless I opt for expensive additives or expensive high mileage oils or expensive boutique oils like RP.
An SM 10w-40 has a few different rules than would an SM 5w-20, and there are even certain differences for SM 10w-30. That's not the only issue. So, no, the SM only 10w-40 does have different requirements than SM 5w-20, from the document you linked. Also, I don't know of any new North American vehicle (or any for many years) that call for a 10w-40.
I haven't seen any newer car manual out there that simply recommended SM certified oil. There is always something else, like GF-4 or the call for the Starburst symbol, which is, actually a GF-4 or GF-5 ILSAC rating, along with a preferred or required viscosity. So, essentially, assuming there aren't proprietary specifications, a newer vehicle will require SM/GF-4 or better.
It's not going to just call for SM and ignore everything else. In the past, sure, but for the past several years, manuals have called for more than one specification, with the API and ILSAC markings both being required as a minimum.
Anyone who would buy the newest Esso XD-3 5w-30 HDEO and put it in a new engine when it doesn't meet the ILSAC specifications could do themselves a disservice if warranty ever became an issue. It simply isn't speced for the vehicle. However, my Audi gets HDEO in the summer, since that is essentially all that's available in the preferred weight.
Besides, the bigger issue is going way out of spec without a carefully researched reason. It's not appropriate to run an SB 5w-30 in a GM vehicle built say in the last 15 years, even though the viscosity would be correct. It's also not correct to run an SM 20w-50 in a the same vehicle, even though the SM might exceed the API standard contemporary to the manufacture.
In some ways, we're making a similar point. We're both saying not to look at one specification in isolation and choose based on that. If one follows the recommendations of one's manual, one will get the correct oil, and it very likely won't be an HDEO for a gasoline engine, particularly if the Starburst symbol is called for in the manual.
There is nothing wrong with HDEOs (and plenty that is right) for people with vehicles of a certain vintage and certain requirements. I'm not going to find a PCMO 15w-40 for my Audi. For my old F-150, I'm not going to find a higher content of ZDDP outside HDEOs, unless I opt for expensive additives or expensive high mileage oils or expensive boutique oils like RP.
I always ran 15-40 Delo in my BMWs, at least in the summer. They were never burned a drop and had fantastic performance, even at 250,000 miles. And, thanks to all the anti-soot additives, they were SPOTLESS. My m50 with 250,000+ miles was FAR cleaner under the VC than my current m54 with only 130,000 miles. And the m54 has always had syn!
Originally Posted By: JRed
I'll stop if it's proven to cause damage.
That's the best line I've ever read on this forum.
I'll stop if it's proven to cause damage.
That's the best line I've ever read on this forum.
Originally Posted By: Papa Bear
Where have you been seeing this ??.....
Perhaps he's referring to the comments of running "diesel oil" in known sludge monsters (or, neglected "used car" purchases even really), for a "short" OCI, to "clean up" the possibility of sludge/dirt/carbon that may be within the crankcase....?
That's one thought.
In fact, I was tempted to start a topic on this the other day, since every "flush" thread, "HDEO" oil use comes up somewhere lol.....but yea, I'm in the school of thought that, thicker can't be good......talking about possibility of blowing seals, or metal:metal contact for the couple seconds before the "thicker" oil can get to where it needs to go....correct?
Well, really, that's the only reason I can think of for running 'diesel' or "HDEO" oil in a gasoline engine.....
Where have you been seeing this ??.....
Perhaps he's referring to the comments of running "diesel oil" in known sludge monsters (or, neglected "used car" purchases even really), for a "short" OCI, to "clean up" the possibility of sludge/dirt/carbon that may be within the crankcase....?
That's one thought.
In fact, I was tempted to start a topic on this the other day, since every "flush" thread, "HDEO" oil use comes up somewhere lol.....but yea, I'm in the school of thought that, thicker can't be good......talking about possibility of blowing seals, or metal:metal contact for the couple seconds before the "thicker" oil can get to where it needs to go....correct?
Well, really, that's the only reason I can think of for running 'diesel' or "HDEO" oil in a gasoline engine.....
Originally Posted By: Garak
However, Gokhan, that applies if the Sx is before the Cx and there is no API certification mark. Many of the HDEOs that I've used do have the certification mark. As for the positioning of the Sx in relation to the Cx, there is a surprising mix out there. I've seen bottles of 10w-40 PCMO with the C ahead of the S, and it still has the API certification mark. So, according to that footnote, the rules would still apply, had other conditions not applied - i.e exemption from P limits because it's 10w-40 and not 0w-20, 5w-20, 0w-30, 5w-30, or 10w-30, to which those limits apply.
No, you are confusing the API Certification Mark "Starburst" with the API Service Symbol "Donut." See Page 16 and 17 (20 and 21 in the PDF file) in the API documentation for the proper naming of the API marks and symbols.
Footnotes (b) and (d) on Page 62 (PDF file page 66) say the following:
(b) If CI-4 and/or CJ-4 categories precede the “S” category and there is no API Certification Mark, the Sequence VG (ASTM D 6593), Ball Rust (ASTM D 6557), and Gelation Index (ASTM D 5133) tests are not required.
(d) For all viscosity grades: If CF-4, CG-4, CH-4 and/or CI-4 categories precede the "S" category and there is no API Certification Mark, the limits for phosphorus, sulfur, and the TEOST MHT do not apply. Note that these oils have been formulated primarily for diesel engines and may not provide all of the performance requirements consistent with vehicle manufacturers' recommendations for gasoline-fueled engines.
All this means is that for 15W-40 C-service (diesel) oils like Chevron Delo, Mobil Delvac, Shell Rotella, etc., some of the performance tests for gasoline engines are not required and these oils may have incorrect (typically excessive) amounts of additives, which may cause emission-systems-component poisoning (such as catalytic-converter or Ox-sensor poisoning [destruction by chemical reaction with the additives]) in gasoline engines, leading to high emissions, engine problems, and expensive repairs, as cautioned explicitly by API in Footnote (d).
However, Gokhan, that applies if the Sx is before the Cx and there is no API certification mark. Many of the HDEOs that I've used do have the certification mark. As for the positioning of the Sx in relation to the Cx, there is a surprising mix out there. I've seen bottles of 10w-40 PCMO with the C ahead of the S, and it still has the API certification mark. So, according to that footnote, the rules would still apply, had other conditions not applied - i.e exemption from P limits because it's 10w-40 and not 0w-20, 5w-20, 0w-30, 5w-30, or 10w-30, to which those limits apply.
No, you are confusing the API Certification Mark "Starburst" with the API Service Symbol "Donut." See Page 16 and 17 (20 and 21 in the PDF file) in the API documentation for the proper naming of the API marks and symbols.
Footnotes (b) and (d) on Page 62 (PDF file page 66) say the following:
(b) If CI-4 and/or CJ-4 categories precede the “S” category and there is no API Certification Mark, the Sequence VG (ASTM D 6593), Ball Rust (ASTM D 6557), and Gelation Index (ASTM D 5133) tests are not required.
(d) For all viscosity grades: If CF-4, CG-4, CH-4 and/or CI-4 categories precede the "S" category and there is no API Certification Mark, the limits for phosphorus, sulfur, and the TEOST MHT do not apply. Note that these oils have been formulated primarily for diesel engines and may not provide all of the performance requirements consistent with vehicle manufacturers' recommendations for gasoline-fueled engines.
All this means is that for 15W-40 C-service (diesel) oils like Chevron Delo, Mobil Delvac, Shell Rotella, etc., some of the performance tests for gasoline engines are not required and these oils may have incorrect (typically excessive) amounts of additives, which may cause emission-systems-component poisoning (such as catalytic-converter or Ox-sensor poisoning [destruction by chemical reaction with the additives]) in gasoline engines, leading to high emissions, engine problems, and expensive repairs, as cautioned explicitly by API in Footnote (d).
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Originally Posted By: eljefino
have done it in summer on troublesome saturns. For a while my stash was chock full of delo 15w40 and I had to use it sometime, so I figured why not have it in there doing a little cleaning.
I also have used Delo in my Saturn as a summer oil.
Ive used it in my Bonneville 3800v6 to flush out all the gunk after I did the intake work on it. No problems for me with either car for a warm weather oil.
have done it in summer on troublesome saturns. For a while my stash was chock full of delo 15w40 and I had to use it sometime, so I figured why not have it in there doing a little cleaning.
I also have used Delo in my Saturn as a summer oil.
Ive used it in my Bonneville 3800v6 to flush out all the gunk after I did the intake work on it. No problems for me with either car for a warm weather oil.
Originally Posted By: ahoier
Well, really, that's the only reason I can think of for running 'diesel' or "HDEO" oil in a gasoline engine.....
As I pointed out, there certainly are other reasons for running HDEO in a gas engine. My gasoline Audi specs 15w-40 for the widest range of temperatures. What 15w-40 do you know of that is commonly available that isn't HDEO? Also, on vehicles that specify a wide range of viscosities, particularly those before manuals started printing 5w-20 or 5w-30 only and the like, HDEOs often fit within what's called for. Also, you're forgetting mixed fleet usage, which is one of the primary intentions behind having a dual rating.
Originally Posted By: Gokhan
All this means is that for 15W-40 C-service (diesel) oils like Chevron Delo, Mobil Delvac, Shell Rotella, etc., some of the performance tests for gasoline engines are not required and these oils may have incorrect (typically excessive) amounts of additives, which may cause emission-systems-component poisoning (such as catalytic-converter or Ox-sensor poisoning [destruction by chemical reaction with the additives]) in gasoline engines, leading to high emissions, engine problems, and expensive repairs, as cautioned explicitly by API in Footnote (d).
I know perfectly well what API markings are. However, for the most part, you are correct. However, also read the tables to which the footnotes apply, rather than just the footnotes themselves. If you read the table itself, you'll see that "oddball" grades such as 10w-40 and 20w-50 are also exempted from those standards, the same as HDEO. 10w-30 also has a different set of standards than does 5w-20, 5w-30 and so forth.
As for damage, we are talking about potential. How much of this has been realized? We don't see cars needing new cats left and right, even those that operated on older oil standards. Further, if a car drinks oil like there's no tomorrow, I doubt that having the reduced ZDDP content of an SM/GF-4 or SN/GF-5 oil is going to help much. The cat will be fouled, and ZDDP will be the least of its problems.
Beyond that, you are missing my point to use properly specified lubricants for your application, whatever that application is. For example, the 2006 Chev pickup I service requires, of course, a viscosity of 5w-30, and by its year, would call for SM. It also calls for GM's proprietary standard.
So, let's say I had my heart set on an HDEO, but I wanted to follow the manual. All I can think of off the top of my head for a 5w-30 HDEO is Esso XD-3 5w-30. Viscosity is 5w-30, check. API rating is SH, so we have a problem. It's certainly not going to meet GM's proprietary standard, so that selection is out.
Everything else is the wrong viscosity, even those that meet SM, and none of them meet the GM numbered specification. When I change oil in that truck, I look for exactly what the manual calls for: a 5w-30 viscosity, SM/GF-4 certification, and GM's numbered specification.
I simply don't know of any HDEO that meets all three standards, so I don't use it. It's not that HDEO itself is harmful; it's not going to be any more harmful than any out of spec oil.
I'm not going to buy a new Vette and run HDEO in it. That being said, I have no problems with running HDEO in my 1984 F-150 or my Audi, since it meets all specifications for both vehicles. Neither vehicles are heavy burners by any stretch of the imagination, and the F-150 doesn't have a cat to "poison."
Well, really, that's the only reason I can think of for running 'diesel' or "HDEO" oil in a gasoline engine.....
As I pointed out, there certainly are other reasons for running HDEO in a gas engine. My gasoline Audi specs 15w-40 for the widest range of temperatures. What 15w-40 do you know of that is commonly available that isn't HDEO? Also, on vehicles that specify a wide range of viscosities, particularly those before manuals started printing 5w-20 or 5w-30 only and the like, HDEOs often fit within what's called for. Also, you're forgetting mixed fleet usage, which is one of the primary intentions behind having a dual rating.
Originally Posted By: Gokhan
All this means is that for 15W-40 C-service (diesel) oils like Chevron Delo, Mobil Delvac, Shell Rotella, etc., some of the performance tests for gasoline engines are not required and these oils may have incorrect (typically excessive) amounts of additives, which may cause emission-systems-component poisoning (such as catalytic-converter or Ox-sensor poisoning [destruction by chemical reaction with the additives]) in gasoline engines, leading to high emissions, engine problems, and expensive repairs, as cautioned explicitly by API in Footnote (d).
I know perfectly well what API markings are. However, for the most part, you are correct. However, also read the tables to which the footnotes apply, rather than just the footnotes themselves. If you read the table itself, you'll see that "oddball" grades such as 10w-40 and 20w-50 are also exempted from those standards, the same as HDEO. 10w-30 also has a different set of standards than does 5w-20, 5w-30 and so forth.
As for damage, we are talking about potential. How much of this has been realized? We don't see cars needing new cats left and right, even those that operated on older oil standards. Further, if a car drinks oil like there's no tomorrow, I doubt that having the reduced ZDDP content of an SM/GF-4 or SN/GF-5 oil is going to help much. The cat will be fouled, and ZDDP will be the least of its problems.
Beyond that, you are missing my point to use properly specified lubricants for your application, whatever that application is. For example, the 2006 Chev pickup I service requires, of course, a viscosity of 5w-30, and by its year, would call for SM. It also calls for GM's proprietary standard.
So, let's say I had my heart set on an HDEO, but I wanted to follow the manual. All I can think of off the top of my head for a 5w-30 HDEO is Esso XD-3 5w-30. Viscosity is 5w-30, check. API rating is SH, so we have a problem. It's certainly not going to meet GM's proprietary standard, so that selection is out.
Everything else is the wrong viscosity, even those that meet SM, and none of them meet the GM numbered specification. When I change oil in that truck, I look for exactly what the manual calls for: a 5w-30 viscosity, SM/GF-4 certification, and GM's numbered specification.
I simply don't know of any HDEO that meets all three standards, so I don't use it. It's not that HDEO itself is harmful; it's not going to be any more harmful than any out of spec oil.
I'm not going to buy a new Vette and run HDEO in it. That being said, I have no problems with running HDEO in my 1984 F-150 or my Audi, since it meets all specifications for both vehicles. Neither vehicles are heavy burners by any stretch of the imagination, and the F-150 doesn't have a cat to "poison."
I should admit that I was using Mobil Delvac 1300 Super LE 15W-40 for the last three years or so and switched to Pennzoil Platinum 5W-30 in the last oil change.
My impression of 15W-40 has been that it puts the engine in unnecessary high stress in highway speeds because of too high oil pressure, apparent from the way the engine sounds. Although, I should say that it could be a great choice for high-load, high-temperature driving such as on the inclines of Nevada highways because you're confident that viscosity breakdown won't be an issue, and I was enjoying flooring the pedal and climbing 6+% slopes at 75 MPH in 110 F weather, passing BMWs along the way.
On the other hand, the engine runs smoother and sounds better with 5W-30 because of the obvious benefits of more optimal viscosity and generous amount of friction modifiers (which greatly improve the efficiency of the antiwear additives but yet are absent in xxW-40 and xxW-50 oils).
Well, I will update on the fuel economy (which seems to have improved quite a bit) and oil consumption after a few hundred more miles. But I already do feel more comfortable with the Starburst SN 5W-30 than I felt with the CJ-4/SM 15W-40 for regular driving and temperatures. Being synthetic probably brings even more protection by extending the oil life.
My impression of 15W-40 has been that it puts the engine in unnecessary high stress in highway speeds because of too high oil pressure, apparent from the way the engine sounds. Although, I should say that it could be a great choice for high-load, high-temperature driving such as on the inclines of Nevada highways because you're confident that viscosity breakdown won't be an issue, and I was enjoying flooring the pedal and climbing 6+% slopes at 75 MPH in 110 F weather, passing BMWs along the way.
On the other hand, the engine runs smoother and sounds better with 5W-30 because of the obvious benefits of more optimal viscosity and generous amount of friction modifiers (which greatly improve the efficiency of the antiwear additives but yet are absent in xxW-40 and xxW-50 oils).
Well, I will update on the fuel economy (which seems to have improved quite a bit) and oil consumption after a few hundred more miles. But I already do feel more comfortable with the Starburst SN 5W-30 than I felt with the CJ-4/SM 15W-40 for regular driving and temperatures. Being synthetic probably brings even more protection by extending the oil life.
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I agree with most of what you're saying. There's absolutely no reason to run to run Delvac 1300 in, say, your Corolla, unless the manual specifies that particular viscosity. If I were driving it, I, too, would go to something in the way of a 10w-30 or 5w-30, or whatever was specified in the manual, and probably use the latest SM or SN Starburst oil. I'm certain it will be better on fuel that way and less sluggish. I don't know what viscosity your manual specifies, but in a 1985 Corolla, a 10w-30 or 5w-30 are reasonable assumptions.
Is the vehicle equipped with a cat? If it is, that engine has gone many, many miles with high ZDDP oils already. My view would be that any modern SM or SN oil (PCMO or HDEO) would be better than what it was fed from that factory, simply because of improved specifications and engineering. I simply wouldn't pick an oil for that vehicle based on trying to squeeze more miles out of a catalytic converter. On the other hand, considering its mileage and likely relatively low output, even if it were a flat tappet design, I wouldn't be all worried that I need a high ZDDP oil to enhance the engine's durability. With a vehicle that's proven its ability to go that many miles, I don't think worrying about the benefits of SM/GL-4 and SN/GL-5 over any harm or benefits from a high ZDDP oil is worth it. In any event, I think the viscosity and type (i.e. SN/GF-5) is a good choice for your vehicle, and I'd likely do the same. As for synthetic, I might not unless I extended the intervals.
For my F-150, a wide range of viscosities are recommended, so I don't worry about using a heavier oil in the summer, and prefer a lighter one in the winter. With a new cam, I would prefer something with a little extra ZDDP, and I'm not a big fan of expensive additives. I'm not going to run RP or Amsoil in the thing, either, so I can get Esso XD-3 HDEO in 5w-30 for winter and 10w-30 in summer, or run the 5w-30 all year. It meets all the specs I require, even the non-SM 5w-30. With no cat and no functioning emissions system, I don't care. Considering it burns no oil (and never did), plug fouling isn't an issue; the fuel dilution issue before caused way more oil and plug problems than did any oil choice.
As for the Audi, I tried Mobil 1 5w-30 a couple winters ago and did GC 0w-30 and QS GB 5w-30 this winter. It consumes all of those - not a lot, but enough to be annoying. With the 40 weight oils, it didn't. That vehicle, too, specifies a very wide range of viscosities, including even down to an xx-20 if the weather warrants it. The heavier grades are heavily favored in the recommendations, and we have all, I'm sure, seen warnings in manuals to monitor consumption when a lighter grade is used.
If there was no consumption issue with a 30 weight, I'd gladly stick to any SM or SN 30 weight dino year round, since such oils show no pressure or temperature anomalies, regardless of the weather. It was also greatly simplify my oil choices.
I just don't like feeding an engine oil for the sake of consumption. Burning a litre or so of SM/SN oil over an OCI is going to give the cat a lot more problems than burning virtually none of high ZDDP HDEO 15-w40 over the same interval.
Is the vehicle equipped with a cat? If it is, that engine has gone many, many miles with high ZDDP oils already. My view would be that any modern SM or SN oil (PCMO or HDEO) would be better than what it was fed from that factory, simply because of improved specifications and engineering. I simply wouldn't pick an oil for that vehicle based on trying to squeeze more miles out of a catalytic converter. On the other hand, considering its mileage and likely relatively low output, even if it were a flat tappet design, I wouldn't be all worried that I need a high ZDDP oil to enhance the engine's durability. With a vehicle that's proven its ability to go that many miles, I don't think worrying about the benefits of SM/GL-4 and SN/GL-5 over any harm or benefits from a high ZDDP oil is worth it. In any event, I think the viscosity and type (i.e. SN/GF-5) is a good choice for your vehicle, and I'd likely do the same. As for synthetic, I might not unless I extended the intervals.
For my F-150, a wide range of viscosities are recommended, so I don't worry about using a heavier oil in the summer, and prefer a lighter one in the winter. With a new cam, I would prefer something with a little extra ZDDP, and I'm not a big fan of expensive additives. I'm not going to run RP or Amsoil in the thing, either, so I can get Esso XD-3 HDEO in 5w-30 for winter and 10w-30 in summer, or run the 5w-30 all year. It meets all the specs I require, even the non-SM 5w-30. With no cat and no functioning emissions system, I don't care. Considering it burns no oil (and never did), plug fouling isn't an issue; the fuel dilution issue before caused way more oil and plug problems than did any oil choice.
As for the Audi, I tried Mobil 1 5w-30 a couple winters ago and did GC 0w-30 and QS GB 5w-30 this winter. It consumes all of those - not a lot, but enough to be annoying. With the 40 weight oils, it didn't. That vehicle, too, specifies a very wide range of viscosities, including even down to an xx-20 if the weather warrants it. The heavier grades are heavily favored in the recommendations, and we have all, I'm sure, seen warnings in manuals to monitor consumption when a lighter grade is used.
If there was no consumption issue with a 30 weight, I'd gladly stick to any SM or SN 30 weight dino year round, since such oils show no pressure or temperature anomalies, regardless of the weather. It was also greatly simplify my oil choices.
I just don't like feeding an engine oil for the sake of consumption. Burning a litre or so of SM/SN oil over an OCI is going to give the cat a lot more problems than burning virtually none of high ZDDP HDEO 15-w40 over the same interval.
It's flat-tappet. The 1985 owner's manual recommends 5W-30 for 50 F (10 C) and below, 10W-30, 10W-40, or 10W-50 for -10 F (-23 C) or above, and 15W-40, 20W-40, or 20W-50 for 10 F (-12 C) or above.
While 5W-30 is recommended for low and only low temperatures, I don't think with a modern synthetic oil and the latest SM or SN grades, 5W-30 vs. 10W-30 is an issue, and I chose 5W-30 over 10W-30 for more friction modifiers and better fuel economy.
With the 15W-40 the consumption would start low but then it would increase and stay steady at about 0.9 quarts per 1,000 miles. There is also some small leak and it's hard to say how much actually was being consumed. The fuel economy was around 27 MPG on the average. The response and horsepower is good.
The engine is running smoother with 5W-30. It will be interesting to see if the consumption will increase or decrease with the synthetic 5W-30. Fuel economy has certainly increased by several MPG. I will update on the numbers after a few hundred more miles.
It always passed the strict California emissions tests, which are performed on a dynamo at 15 MPH and 25 MPH.
By the way I also used the PureOne PL10241 oil filter with 99.9% efficiency in the previous oil change, but I switched back to the Toyota filter because I'm worried that the PureOne, thanks to its super high efficiency, will easily clog and restrict the oil flow or open the bypass valve.
While 5W-30 is recommended for low and only low temperatures, I don't think with a modern synthetic oil and the latest SM or SN grades, 5W-30 vs. 10W-30 is an issue, and I chose 5W-30 over 10W-30 for more friction modifiers and better fuel economy.
With the 15W-40 the consumption would start low but then it would increase and stay steady at about 0.9 quarts per 1,000 miles. There is also some small leak and it's hard to say how much actually was being consumed. The fuel economy was around 27 MPG on the average. The response and horsepower is good.
The engine is running smoother with 5W-30. It will be interesting to see if the consumption will increase or decrease with the synthetic 5W-30. Fuel economy has certainly increased by several MPG. I will update on the numbers after a few hundred more miles.
It always passed the strict California emissions tests, which are performed on a dynamo at 15 MPH and 25 MPH.
By the way I also used the PureOne PL10241 oil filter with 99.9% efficiency in the previous oil change, but I switched back to the Toyota filter because I'm worried that the PureOne, thanks to its super high efficiency, will easily clog and restrict the oil flow or open the bypass valve.
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