Why are newer cars using thinner motor oils?
- Thread starter AdrienneOwens
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I was one who for years believed that, "thicker was better". I no longer do. If you look at the overall picture, engines are lasting longer... Much longer than they used to, when most ran heavy weight oils. In the 60's you bragged at the bar if your engine went 100,000 miles without having to remove the heads for a "valve job". Now you don't change spark plugs or coolant until then. 100,000 miles on today's new cars is nothing. Many are easily going 200,000 or even 300,000 miles or more. That isn't because, "thin oils wear more".
Also, there are many other reasons new engines require the thinner oils. And why it's very important NOT to substitute them with higher viscosity versions of the same oil. For example, my 2015 Jeep Grand Cherokee is equipped with the 5.7 HEMI V-8. It has both MDS, (Multi Displacement System), and VVT, (Variable Valve Timing). Both require 5W-20 oil that meets or exceeds Chrysler Spec MS-6395 in order to operate properly. If you substitute a heavier weight oil, these systems won't function correctly. And you will have serious warranty issues if something gets damaged, and they can trace the failure to the wrong oil. There is a lot more going on here than phantom wear that really isn't happening. I put, "engines need thicker oil to last longer", into the same category that these same engines, "need leaded fuel to properly lubricate the valves". All nonsense.
Also, there are many other reasons new engines require the thinner oils. And why it's very important NOT to substitute them with higher viscosity versions of the same oil. For example, my 2015 Jeep Grand Cherokee is equipped with the 5.7 HEMI V-8. It has both MDS, (Multi Displacement System), and VVT, (Variable Valve Timing). Both require 5W-20 oil that meets or exceeds Chrysler Spec MS-6395 in order to operate properly. If you substitute a heavier weight oil, these systems won't function correctly. And you will have serious warranty issues if something gets damaged, and they can trace the failure to the wrong oil. There is a lot more going on here than phantom wear that really isn't happening. I put, "engines need thicker oil to last longer", into the same category that these same engines, "need leaded fuel to properly lubricate the valves". All nonsense.
And let's not forget the oil itself. Does anyone really want to compare, "Arco Graphite" and "Cam 2" dinosaur oil, that was considered top of the line back in those days. To today's ultra refined, high mileage modern synthetics? It's like comparing an incandescent light bulb to a modern high output LED. So while running a heavier oil back then, in an attempt to save wear might have had some merit. It doesn't offer todays modern engines any benefit. And may in fact cause problems that running the proper weight oil would avoid.
Originally Posted By: Shannow
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
Unless there is a simple if>then logic built into the system to keep it from operating until a certain temperature is reached.
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
Unless there is a simple if>then logic built into the system to keep it from operating until a certain temperature is reached.
What's the typical operating temperature, and hence typical oil operating pressure of a VVT in action , that a one grade thicker engine oil would not 'function correctly' ?
.... if a VVT not 'function correctly' was established to be 'solely' caused by thicker oil (in oil operating pressure ) ?
.... if a VVT not 'function correctly' was established to be 'solely' caused by thicker oil (in oil operating pressure ) ?
Originally Posted By: rooflessVW
Originally Posted By: Shannow
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
Unless there is a simple if>then logic built into the system to keep it from operating until a certain temperature is reached.
Apparently 120F (50C)...so if viscosity is the limiting factor, then 40cst is it...IF it was designed to be damaged on anything other than 5W20.
Originally Posted By: Shannow
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
Unless there is a simple if>then logic built into the system to keep it from operating until a certain temperature is reached.
Apparently 120F (50C)...so if viscosity is the limiting factor, then 40cst is it...IF it was designed to be damaged on anything other than 5W20.
Originally Posted By: Shannow
Originally Posted By: rooflessVW
Originally Posted By: Shannow
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
Unless there is a simple if>then logic built into the system to keep it from operating until a certain temperature is reached.
Apparently 120F (50C)...so if viscosity is the limiting factor, then 40cst is it...IF it was designed to be damaged on anything other than 5W20.
Has anyone claimed damage? I could see the system not working correctly with an oil that's too thick. It is a hydraulic system, after all. A weird idle or CEL wouldn't be outside the realm of possibility.
Part of Porsche A40 approval is Variocam function... Too thick and you'll get a weird idle and timing errors. Mobil 1 FS X2 5W-50 has Porsche A40 approval, 15W-50 does not.
Originally Posted By: rooflessVW
Originally Posted By: Shannow
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
Unless there is a simple if>then logic built into the system to keep it from operating until a certain temperature is reached.
Apparently 120F (50C)...so if viscosity is the limiting factor, then 40cst is it...IF it was designed to be damaged on anything other than 5W20.
Has anyone claimed damage? I could see the system not working correctly with an oil that's too thick. It is a hydraulic system, after all. A weird idle or CEL wouldn't be outside the realm of possibility.
Part of Porsche A40 approval is Variocam function... Too thick and you'll get a weird idle and timing errors. Mobil 1 FS X2 5W-50 has Porsche A40 approval, 15W-50 does not.
Quote:
.....about 80% of engine wear occurs at start....
Everything I've read (including on here) points to the vast majority of engine wear occuring during the actual oil warmup period from ambient to 170-180 degF hot oil temps, where corrosion is the main culprit. That takes 10-20 minutes typically for most cars, in normal environments. The initial turning over the engine (1-5 seconds), before full oil flow is established, is protected by the viscosity of the oil. As long as you're at an ambient temp where a 0w/5w/10w-30 oil will crank and flow, those should protect as well or better than a 0w-20.
Because I am concerned about engine failure and max longevity, I'd gladly hand over a $300 check in fuel savings at time of purchase if I'm guaranteed my engine lasts as long as I own it. I consider $300 to be a minor tax rather than spending $3500-$4500 for a new engine. And since even "routine" maintenance jobs on engines can cost $1,000+ (head gaskets, timing chains + guides, etc.) I want the optimum oil to ensure I don't fork over those $1,000 bills along the way.
.....about 80% of engine wear occurs at start....
Everything I've read (including on here) points to the vast majority of engine wear occuring during the actual oil warmup period from ambient to 170-180 degF hot oil temps, where corrosion is the main culprit. That takes 10-20 minutes typically for most cars, in normal environments. The initial turning over the engine (1-5 seconds), before full oil flow is established, is protected by the viscosity of the oil. As long as you're at an ambient temp where a 0w/5w/10w-30 oil will crank and flow, those should protect as well or better than a 0w-20.
Because I am concerned about engine failure and max longevity, I'd gladly hand over a $300 check in fuel savings at time of purchase if I'm guaranteed my engine lasts as long as I own it. I consider $300 to be a minor tax rather than spending $3500-$4500 for a new engine. And since even "routine" maintenance jobs on engines can cost $1,000+ (head gaskets, timing chains + guides, etc.) I want the optimum oil to ensure I don't fork over those $1,000 bills along the way.
Originally Posted By: tig1
(about 80% of engine wear occurs at start)
As pointed out, it's as much wear occurs in the first 20 minutes as the next half dozen hours. The wear occurs DURING the warmup phase, while the components aren't at operating temperature.
The industry standard warmup wear test - Sequence IVA holds the engine at lower than normal operational temperature, any colder and the wear is less due to viscosity. Any hotter, and the additives are more active. Formulator BobbyDavro states that he's demonstrated this effect in the lab, the chosen mid point is the "perfect storm" with rese[ect to WARMUP wear.
But, we've been over it before, and it still gets trotted out that it's the seconds before oil pressure is established...
Which, as I've also pointed out, including excerpts from papers, with positive displacement pumps and the oil in it's reasonably pumpable range is no different between 0W anything and SAE 30.
(about 80% of engine wear occurs at start)
As pointed out, it's as much wear occurs in the first 20 minutes as the next half dozen hours. The wear occurs DURING the warmup phase, while the components aren't at operating temperature.
The industry standard warmup wear test - Sequence IVA holds the engine at lower than normal operational temperature, any colder and the wear is less due to viscosity. Any hotter, and the additives are more active. Formulator BobbyDavro states that he's demonstrated this effect in the lab, the chosen mid point is the "perfect storm" with rese[ect to WARMUP wear.
But, we've been over it before, and it still gets trotted out that it's the seconds before oil pressure is established...
Which, as I've also pointed out, including excerpts from papers, with positive displacement pumps and the oil in it's reasonably pumpable range is no different between 0W anything and SAE 30.
I believe 20wt in somewhat lower in calories
Gosh, so, my car spends 100% of it's time wearing out ! Except when it starts up. Maybe I just shouldn't use it.
Originally Posted By: 69GTX
Quote:
.....about 80% of engine wear occurs at start....
Everything I've read (including on here) points to the vast majority of engine wear occuring during the actual oil warmup period from ambient to 170-180 degF hot oil temps, where corrosion is the main culprit.
Spot on.
Quote:
Because I am concerned about engine failure and max longevity, I'd gladly hand over a $300 check in fuel savings at time of purchase if I'm guaranteed my engine lasts as long as I own it. I consider $300 to be a minor tax rather than spending $3500-$4500 for a new engine. And since even "routine" maintenance jobs on engines can cost $1,000+ (head gaskets, timing chains + guides, etc.) I want the optimum oil to ensure I don't fork over those $1,000 bills along the way.
This is perceived .... and it may not be true at times.
By over-pressure 20-30% higher than OEM's, I possibly get back 2-3 times of $300 check ... IDK.
Quote:
.....about 80% of engine wear occurs at start....
Everything I've read (including on here) points to the vast majority of engine wear occuring during the actual oil warmup period from ambient to 170-180 degF hot oil temps, where corrosion is the main culprit.
Spot on.
Quote:
Because I am concerned about engine failure and max longevity, I'd gladly hand over a $300 check in fuel savings at time of purchase if I'm guaranteed my engine lasts as long as I own it. I consider $300 to be a minor tax rather than spending $3500-$4500 for a new engine. And since even "routine" maintenance jobs on engines can cost $1,000+ (head gaskets, timing chains + guides, etc.) I want the optimum oil to ensure I don't fork over those $1,000 bills along the way.
This is perceived .... and it may not be true at times.
By over-pressure 20-30% higher than OEM's, I possibly get back 2-3 times of $300 check ... IDK.
Originally Posted By: Shannow
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
I didn't say it "disables it". It causes problems that using the proper weight motor oil avoids. Go on any Jeep forum and there are countless threads from guys who think they know more than the engineers at Chrysler do. And have both MDS and VVT issues because they try running heavier weight oils. After they realize they weren't so smart and switch back, their issues disappear.
Does your MDS system function at anything less than operating temperature ?
Does MDS work in Canada in winter ?
If so, then this "thick oil disables the MDS" is baseless drivel.
I didn't say it "disables it". It causes problems that using the proper weight motor oil avoids. Go on any Jeep forum and there are countless threads from guys who think they know more than the engineers at Chrysler do. And have both MDS and VVT issues because they try running heavier weight oils. After they realize they weren't so smart and switch back, their issues disappear.
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