One uoa good results 30 versus 20 weight

[burla]

I don't know if the guy will post it here and no I'm not cherry picking, this is the first multiple runs uoa with an engine that is broken in that I have seen over on another website, yes hemi's are high wear engines get that out of the way first. 4 uoa's, last one 30 weight then 2 20 weight runs and first looks like another 30 weight, wear dropped like a hot rock. Additive packages look very similar, last run PUP.

Milage Miles on oil cSt Wear Metals
60,864 11,250 10.16 A-4 I-24 C-21
49,804 12,818 8.84 A-6 I-40 C-31
35,786 14,000 8.93 A6 I-43 C-46
22,634 10,184 9.79 A6 I-28 C-78

It looks like he went 30,20,20 and then 30 as far as weights. I chalk the high copper to a young engine in the first uoa, that oil was put in with only 12k miles on the truck. But looking at the numbers one could easily say the 30 weight is producing less wear. I don't know if the guy is a member here or wants me to post the uoa, but this is the meat of the uoa. Last run was PUP, likely all the runs are PUP, bt I don't know for sure other then very similar additive packages. The first uoa's iron was amazing as well as the last, both 20 weight runs not so much.

 

[RazorsEdge]

I'm not sure what the point of this is but we've got a 1996 Crown Victoria that was purchased with 65,000 miles from an auction.

Today we've got 320,000 miles + on the engine and we've used 5w20,and 5w30 and the car is basically rusting apart so what difference does it make if your using a 20 vs a 30 weight? The car/truck is going to run forever if you take care of it!

 

[burla]

Looks like 30 weight is doing a little better in this 390 hp vehicle, that's all. hemi's are high wear engine and prone to have issues, and yes some go 390k miles on grand dads oil, but why ever have an oil forum, lol.

 

[JAG]

There is definitely a strong trend of higher viscosity and less iron detected.

 

[wemay]

As pointed out bellow and thanks to Doug Hillary's explanation, I thought samples were for monitoring oil life and contamination, not wear...

 

[JAG]

I agree, Wemay. That's why I said less iron detected. I can't say there is less true total mass of iron/steel wear.

 

[wemay]

 

[ka9mnx]

Isn't iron in UOI from rust (can't think of a better word)?

 

[JAG]

Iron in oil is from wear or rust from cast iron or steel. Almost no engines significantly rust on the inside. It would have to have a lot of condensation inside for a long time with a lame oil.

 

[ka9mnx]

Thanks JAG!

 

[WyrTwister]

Originally Posted by burla
Looks like 30 weight is doing a little better in this 390 hp vehicle, that's all. hemi's are high wear engine and prone to have issues, and yes some go 390k miles on grand dads oil, but why ever have an oil forum, lol.



Why are hemi's high wear ? Because people are prone to put their foot in them or is a basic design issue ?

 

[PimTac]

Not a good comparison. The 20 weights had a longer oci than the other two oils.

 

[burla]

Originally Posted by WyrTwister
Originally Posted by burla
Looks like 30 weight is doing a little better in this 390 hp vehicle, that's all. hemi's are high wear engine and prone to have issues, and yes some go 390k miles on grand dads oil, but why ever have an oil forum, lol.



Why are hemi's high wear ? Because people are prone to put their foot in them or is a basic design issue ?


Nah, poor quality parts. I am a an old truck driver, they call me grandpa or milk man since I was in my twenties because I drive so slow. My personal uoa's were way worse then those, but I was in a hemi tick condition as well. But every hemi uoa we have seen is way over most applications.

Those tests certainly aren't perfect as far as mileage, but that is when he changed the oil. If someone was going to consider running 30 weight in a 20 weight application like the hemi, I would suggest doing your own test.

 

[zorobabel]

Originally Posted by PimTac
Not a good comparison. The 20 weights had a longer oci than the other two oils.


I noticed that too.

 

[dave1251]

One the 20 grade tests the oil was used longer, the sample size is no where large enough, and ppm if wear metals in a UOA really does not mean much. More comformation bias IMO.

 

[OVERKILL]

Originally Posted by burla


Milage Miles on oil cSt Wear Metals
60,864 11,250 10.16 A-4 I-24 C-21
49,804 12,818 8.84 A-6 I-40 C-31
35,786 14,000 8.93 A6 I-43 C-46
22,634 10,184 9.79 A6 I-28 C-78

It looks like he went 30,20,20 and then 30 as far as weights. I chalk the high copper to a young engine in the first uoa, that oil was put in with only 12k miles on the truck. But looking at the numbers one could easily say the 30 weight is producing less wear.


(Reversed from above):

Run A: 2.75ppm/1K miles (Fe)
Run B: 3.07ppm/1K miles (Fe)
Run C: 3.12ppm/1K miles (Fe)
Run D: 2.13ppm/1K miles (Fe)

Copper seems to be trending down slowly as the miles rack up. Iron wear is 1ppm per 1K miles higher with the two middle oils, which is insignificant.

 

[OVERKILL]

Originally Posted by WyrTwister
Originally Posted by burla
Looks like 30 weight is doing a little better in this 390 hp vehicle, that's all. hemi's are high wear engine and prone to have issues, and yes some go 390k miles on grand dads oil, but why ever have an oil forum, lol.



Why are hemi's high wear ? Because people are prone to put their foot in them or is a basic design issue ?


Some UOA's indicate that they shed higher levels of metals than some OHC engines, but you can't just blindly compare wear metals between different engine families. GM's LS-family engines also shed higher ppm per 1k miles yet are well-known to be quite durable and long-lived.

 

[burla]

I'm not, I suggest this is exclusively something someone with hemi's might consider, testing 30 weight in that 390 hp engine rather then run 20 weight. Of course we have other uoa's that have shown very good wear numbers with long term use of 5w30. This one was a little different as he went 30,20,20,30.

 

[OVERKILL]

Originally Posted by burla
I'm not, I suggest this is exclusively something someone with hemi's might consider, testing 30 weight in that 390 hp engine rather then run 20 weight. Of course we have other uoa's that have shown very good wear numbers with long term use of 5w30. This one was a little different as he went 30,20,20,30.


I don't think it would be of detriment, but that doesn't imply that there is verified benefit either. We do of course know that the 6.4L spec's 0w-40, and that's about the closest thing to an eyebrow raiser in this that we can see IMHO.

 

[wemay]

Originally Posted by burla
I'm not, I suggest this is exclusively something someone with hemi's might consider, testing 30 weight in that 390 hp engine rather then run 20 weight. Of course we have other uoa's that have shown very good wear numbers with long term use of 5w30. This one was a little different as he went 30,20,20,30.


...and oci were different.

I've seen excellent UOA using both, 20 and 30.