Synthetic Oil

joshuaeb09 said:

Density plays a role in the viscosity of an oil at a given temperature outside of any modifiers like VII's, which increase viscosity on other principles than just fluid density as they are actually less dense when they expand. However the density change is not a 1:1 viscosity change as noted by the 2nd link's set of charts. A prime example of this is the chart for the straight 30 weight. Pretty much the only numbers you should be concerned with are the viscosity at a given temperature as the density will also either change differently or have a different impact depending on the nature of the base oil and any modifiers like VII's.

https://www.engineeringtoolbox.com/...cant-volume-correction-ASTM-D1250-d_1943.html
https://wiki.anton-paar.com/en/engine-oil/

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Burla said:

I don't want to open a bag of worms, oops too late, but what I wonder is if their HP line is actually dyed amber to look like oil. If so that would be funny, RP dyes their oil to look synthetic, and redline dyes their synthetic to look like oil. Ha, no I have zero info on this, I just wondered about it.

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U&A said:

If im understand the charts correctly. SAE30 (Straight weight) has slightly more density than their 2nd place contender 15w40.

Kinda figured that

This is exactly what most of us have been assuming all along is the closer together the numbers are to a straight weight the denser oil (relative to its counterpart in a multi viscosity)

The one thing most people don’t know is straight weight still act like multi weight oils.
For example. A lot of SAE30’s could almost pass as a 10w30. This makes me even more want to try 10W-40 again. Or even something more off the wall.

Im going to contact dave if nobody else hasn’t already and see if I can get density numbers on their blue label oil’s.
[emoji3595]Burla, did you do this already?

Iv often wondered if conventional oils are slightly more dense than full synthetics when they are of similar viscosity.

For example True synthetic oil molecules are extremely symmetrical like a sphere. Whereas conventional oil molecules are blockier. Though the sphere shaped molecules will provide better protection the blockier ones almost have more resistance to being pushed out of the way.... so that could make them more “dense” ....? Think of one of them ball pits that kids play in. The sphere’s move easy. Now make the same pit with plastic blocks of different size and shape. They Don’t move so easy now...

Density is definitely something to keep looking into IMO...




Sent while firmly grasping my redline lubed RAM [emoji231]

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HammerHead said:

I find that interesting; conventional oil (Group 2) having blocky molecules. Might be a denser oil per weight over a Group 3.
I’m thinking that’s why High mileage engines do better on conventional oils.
And less oil consumption?

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U&A said:

Explain you view on how conventional could lower consumption. Im interested in that though.

I was thinking the high milage oils get less consumption because they are always thicker


Sent while firmly grasping my redline lubed RAM [emoji231]

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joshuaeb09 said:

That depends on the oil and how its going to sheer as well as the engine it's going in. For my 5.7 with its 180 T-Stat it really likes the ~12 CST of Redline 5W30 or PUP 0W40 once it sheers down. The oil does run a bit colder at around 195 empty so it's going to be a touch thicker than the advertised hot visc at 212. The 6.4 being an SRT has higher compression (10.9:1) and gets hot once it's been worked so the ~15.5 CST of the RL 0W40/5W40 works well there since the oil is usually right around 210 with a 180 T-Stat and can get up to 240-250ish when it's being pushed for a while.

Since the 6.4 truck configuration has that 216 T-stat I would probably shoot for around the same, taking into account how much the oil will sheer during the OCI. If it's under high loads then the thicker rated oil, again in that 15 range, will thin out a bit at elevated oil temps and maintain better protection.

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U&A said:

My redline UOA as well as many others show literally zero loss in viscosity or close to non.

My last one was exactly the same as new oil.

I think Cory and Rons UOA also had very impressive viscosities that were basically like new and they both worked their trucks pretty good.

Redline holds it VERY well


Sent while firmly grasping my redline lubed RAM [emoji231]

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U&A said:

I called NGK and a really nice gentleman helped me out with understanding all of this. He said that you can use their copper, platinum, or some new fancy plug that is better than iridium.

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Zack02 said:

Interesting, thanks for running that down. Did you ask him about the coils? Are you going change out the coil packs to the ones for the coppers? Having a hotter sparker can lead to pre-ignition issues, or are you not worried about it?
I didn't have any pre-ignition issues, but they were definitely getting hot.

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joshuaeb09 said:

Yup. I love me that sheer stability. Don't have to dump it after 500 miles cause I've sheered it to hell staying in the power band during a single twisted sisters run.

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Zack02 said:

Interesting, thanks for running that down. Did you ask him about the coils? Are you going change out the coil packs to the ones for the coppers? Having a hotter sparker can lead to pre-ignition issues, or are you not worried about it?
I didn't have any pre-ignition issues, but they were definitely getting hot.

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Burla said:

We don't discuss that enough, especially guys with the 6.4 running 0w40, but when you loose a point of visc due to shear that is 10% of your protection, you loose 2 and that is 20%, but the oil pump does make up for some of that and it is likely figured into fca's desicision to run that oil along with the stoutness of 0w40's as mentioned, but still they most important specs are mercedes and porsche, so if your 0w40 has those specs as well you have done all you can within that weight.

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U&A said:

I just listened to the 5.0 in an F150 have terrible start up tic. It mostly went away within two seconds or so but then turned into a hot idle tic.

Good lord

It’s everywhere!!!


Sent while firmly grasping my redline lubed RAM [emoji231]

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crackerjack1957 said:

Never had an older adjustable valvetrain engine that had a tick issue only on the non-adjustable.

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OMW2SKI said:

Time for an oil change. I did 2 changes before getting a prepaid package (courtesy of Ramcares due to the OTA update fiasco). First 2 changes were Mobil 1 and PUP. IMHO, PUP did not run as quiet as the Mobil 1. Dealer was using Penzoil synthetic - but I doubt PUP. Truck is a little noisy when cold. Gonna give QSUD a shot. It's more readily available than Redline or PUP. Found it at Walmart for $18/5 quarts. Always used MOPAR filter and 5W20. Adding some Liqui Moly MOS2 this time around. Hopefully it will quiet down those cold starts a little.

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GottaBeKD said:

Do we know how the QSUD 5w30 fairs with shearing?

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