5w 20 or 5w30

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WaRam2012

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I have just put a new engine in my 2012 Ram 5.7 I live in the North West and I have been debating on going to 5w 30 on my first oil change I have always ran Amsoil in my other vehicles I’m sure this oil debate has been ran to death but just would like some input
Thanks in advance
 

ramffml

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Always run 0/5w-30 in a hemi. You get far better protection. 20 weight is for CAFE reasons only.

The "engineers know best" comments you'll inevitably get are wrong because they assume engineers get the final say.

Redline 5w-30 is a great candidate, as is Mobil 1 FS 0w-40 with LG, and HP oil looks incredible as well.

Amsoil has been reported to make hemis clatter/noisy. I wouldn't run it.
 

Wild one

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I know this is a controversial topic; my response to this question is always "the manufacturer's recommendation". Personally, I don't ever think it's a good idea to try and outsmart the engineers who designed an engine.
The note at the bottom might interest you.
 

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1979PowerWagon360

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Always run 0/5w-30 in a hemi. You get far better protection. 20 weight is for CAFE reasons only.

The "engineers know best" comments you'll inevitably get are wrong because they assume engineers get the final say.

Redline 5w-30 is a great candidate, as is Mobil 1 FS 0w-40 with LG, and HP oil looks incredible as well.

Amsoil has been reported to make hemis clatter/noisy. I wouldn't run it.
I respectfully disagree that the engineers recommendation is for CAFE only. I'm basing my opinion on an entire fleet of cars over a long period. Again, I respect your opinion but don't share it.
 

Burla

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I have just put a new engine in my 2012 Ram 5.7 I live in the North West and I have been debating on going to 5w 30 on my first oil change I have always ran Amsoil in my other vehicles I’m sure this oil debate has been ran to death but just would like some input
Thanks in advance
Since you brought up amsoil, look at their sheets. 5w30 operates at 10.3 visc, 5w20 operates at 8.8 visc, now look at the next weight up which is 0w40 that operates at viscosity 14.8. The point is 5w20 and 5w30 are thin oils not much difference either way, the 5w30 will give you a little more film strength. You can see when you jump to 40 weight you have a real heavy duty oil, whereas 5w30/5w20 are just your basic passenger vehicle oil. For a 2012 no doubt you want to be thicker, as tolerances widen you don't want thin oil. If you get a used oil analysis sometime, post it in blackstone thread in 4 gen performance section for feedback on what your engine is doing.

EPA uses CAFE standards to force manu's to use thin oils. Since CAFE is impossible to make the goals of, manu's need to prove they tried everything. It has been posted ad naseum. FCA engineers made hemi specific oil 0w40 for a reason, but they literally cant use that oil in a 1500 non HD vejicle.




.
 

ramffml

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I respectfully disagree that the engineers recommendation is for CAFE only. I'm basing my opinion on an entire fleet of cars over a long period. Again, I respect your opinion but don't share it.

It becomes easier to accept when you ask your same question about other components, like the plastic oil cooler on the 3.6. Do you think engineers said "lets make this plastic, it will last longer than (say) aluminum", or, do you think it's more likely the bean counters walked in and said "aluminum costs too much, make it plastic".

All of engineering is a compromise one way or the other. 30 weights generally offer more protection (MOFT) but slightly less MPG (fractions of a percent). The industry trend towards thinner and thinner oils is stricktly for better fuel economy, not because it's better protection for the engine.
 
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Burla

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This was a long time ago a nice summary, the situation is far worse today, I mean damn they are trying to ban gas engines.

Motor Oils - Fuel Economy vs. Wear​

Blaine Ballentine, Central Petroleum Company
Conventional wisdom states that engine oils that increase fuel economy allow less friction and prolong engine life. The purpose of this article is to challenge conventional wisdom, particularly concerning modern (GF-3 ILSAC/API Starburst) engine oils.

Fuel Economy: Does Anyone Really Care?​

First, we should face the fact that the American consumer does not typically care about fuel economy except during difficult economic times. The No. 1 selling passenger vehicle is the Ford F-Series Pickup. Five of the top 10 best-selling vehicles are trucks, and trucks outsell cars.

Backup_200307_PractLub-Fig1.jpg
Figure 1. Bearing Wear
Additionally, consider how most vehicles are driven. Anyone accelerating slowly or driving at the speed limit to conserve energy is a danger to himself and other drivers who are in a much bigger hurry.
Auto manufacturers, on the other hand, are concerned about fuel economy. The manufacturer faces big fines if the fleet of cars it produces falls short of the Corporate Average Fuel Economy (CAFE) requirements imposed upon them by the federal government.

The March to Thinner Oils​

Thinner oils are being used these days for three reasons: They save fuel in test engines, the viscosity rules have changed, and manufacturers are recommending thinner grades.
The Sequence VI-B is the test used to evaluate fuel economy for the GF-3 specification. The VI-B test engine is fitted with a roller cam where the old Sequence VI test used a slider cam. The old Sequence VI test responded well to friction modifiers, but the Sequence VI-B responds to thinner oils.
The test oil’s fuel efficiency is compared to the fuel efficiency of a reference oil in the Sequence VI-B test. To pass, the test oil must improve fuel economy one to two percent, depending on viscosity grade. SAE 5W-20 must produce higher relative fuel efficiency than SAE 5W-30.
It is interesting to note that the reference oil is fully PAO synthetic SAE 5W-30. To qualify for the GF-3 Starburst, ordinary mineral oils had to beat the fuel economy of the full synthetic reference oil. (It seems there is more to fuel economy than a magic base oil.)
Another factor in fuel economy is temporary polymer shear. These polymers are additives known as viscosity index improvers (or modifiers). Polymers are plastics dissolved in oil to provide multiviscosity characteristics. Just as some plastics are tougher, more brittle or more heat-resistant than others, different polymers have different characteristics.
Polymers are huge molecules with many branches. As they are heated, they uncoil and spread out. The branches entangle with those of other polymer molecules and trap and control many tiny oil molecules. Therefore, a relatively small amount of polymer can have a huge effect on oil viscosity.
As oil is forced between a bearing and journal, many polymers have a tendency to align with each other, somewhat like nesting spoons. When this happens, viscosity drops. Then when the oil progresses through the bearing, the polymer molecules entangle again and viscosity returns to normal. This phenomenon is referred to as temporary shear.
Because the Sequence VI-B test responds to reductions in viscosity, oil formulators rely on polymer shear to pass the test. A shear stable polymer makes passing the GF-3 fuel economy test much more challenging.
New rules defining the cold-flow requirements of SAE viscosity grades (SAE J300) became effective in June 2001. The auto manufacturers were afraid that modern injection systems might allow the engine to start at temperatures lower than the oil could flow into the oil pump. Consequently, the new rules had a thinning effect on oil.
The auto manufacturers now recommend thinner oils for their vehicles than in the past. Years ago, SAE 10W-40 was the most commonly recommended viscosity grade, later migrating to SAE 10W-30. SAE 5W-30 is most popular now, but Ford and Honda recommend SAE 5W-20. It is likely that more widespread adoption of SAE 5W-20 and other thin oils may occur to help comply with CAFE requirements.
 

HEMIMANN

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Always run 0/5w-30 in a hemi. You get far better protection. 20 weight is for CAFE reasons only.

The "engineers know best" comments you'll inevitably get are wrong because they assume engineers get the final say.

Redline 5w-30 is a great candidate, as is Mobil 1 FS 0w-40 with LG, and HP oil looks incredible as well.

Amsoil has been reported to make hemis clatter/noisy. I wouldn't run it.

Some of the engineers I worked with were idiots. Or newbs that were over their head cause corporate fired experienced engineers, leaving newbs to flounder. All they could do was code software.

Don't make me break out the Elasto Hydrodynamic Lubrication Book.
 

Burla

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Lubrication fascists for sure, the state takes precedence over individual interests. If you want to best protect your engine, you are guilty of crimes against the state, lol.
 

HEMIMANN

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Also - for the same reasons and requirements @Burla notes above, 0W's came into existence. Along with API SP qualifications, GF-6, etc.

In moderate cold climates, 5W-30 still the optimal viscosity range for most Hemi applications. If you're towing 12,000 lbs up the Sierra Nevada for miles in 100F heat, then 5W-40 probably better.

If you're up in @Wild one land, then 0W-30 for cold starts.
 

Wild one

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Also - for the same reasons and requirements @Burla notes above, 0W's came into existence. Along with API SP qualifications, GF-6, etc.

In moderate cold climates, 5W-30 still the optimal viscosity range for most Hemi applications. If you're towing 12,000 lbs up the Sierra Nevada for miles in 100F heat, then 5W-40 probably better.

If you're up in @Wild one land, then 0W-30 for cold starts.
Hey we use Whale Oil up here, :Big Laugh: :cheers:
 

06 Dodge

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I have just put a new engine in my 2012 Ram 5.7 I live in the North West and I have been debating on going to 5w 30 on my first oil change I have always ran Amsoil in my other vehicles I’m sure this oil debate has been ran to death but just would like some input
Thanks in advance

You did not say if this was a crate engine or reman, if reman I would use a good 5w30 dino oil & filter, run it for a 1000 miles dump oil then do one more run for 2,000 miles again with dino oil 5w30 then switch to synthetic oil of your choice..., If crate engine then I would use a semi synthetic 5w30 oil for 3,000 then change to the synthetic oil of your choice...
 

MontanaHandyman

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Some of the engineers I worked with were idiots. Or newbs that were over their head cause corporate fired experienced engineers, leaving newbs to flounder. All they could do was code software.

Don't make me break out the Elasto Hydrodynamic Lubrication Book.
Please do!
 
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