Yellow Pennz vs PP 5w30 06 Jeep GC 4.7l

[Scottydog]

Here is an interesting comparison. Same 4.7l engine 5w30 Yellow bottle vs PP.

PP held up better, despite more miles, esp viscosity. Blackstone suggested running 6500 miles on the synthetic.

Anyone still think PP is a waste for this vehicle?



JEEP 4.7l V8 24,000 total miles


Miles on Oil PP-5300 / Pennz Yel-4500

(first # is PP, 2nd is Pennz Yellow)
AL 2 2
CHROMIUM 1 1
IRON 13 9
COPPER 1 1
LEAD 1 0
TIN 0 0
MOLY 71 166
NICKEL 1 1
MANG 0 0
SILVER 0 0
TITANIUM 0 0
POTASSIUM 3 3
BORON 31 23
SILICON 9 7
SODIUM 8 6
CALCIUM 2944 1405
MAGNESIUM 14 3
PHOS 679 472
ZINC 829 554
BARIUM 0 0

SUS 60 56
CST VIS 10.2 9.18
FLASH 415 316
TBN 4.2 3.1

 

[glennc]

What were fuel numbers? Flash is much lower on the yellow-bottle sample. If it was fuel that would explain the viscosity difference and the idea that PP held up better would be out the window.

Also how many miles on each sample, and in what order were the oils run?

Without that info it is difficult to draw good conclusions.

 

[Scottydog]

Yellow was run first, then PP. 4500 on yellow, 5300 on PP.

Yellow did have trace fuel, PP <.5

 

[glennc]

With so few miles on the engine I'd expect wear metals to be trending down. The fact that yellow did better sooner on the break-in curve, even with a few less miles on the sample, makes it look like the better-performing oil, to me. Both are good, of course. I don't know how "trace" fuel compares to
The engine is obviously doing fine, though.

 

[Brett Miller]

I run PP 5W-30 for 6,000 mile intervals in my Parents Jeep 4.7L. I would stay will PP, it seems for work well in about any engine.

 

[badtlc]

I'd agree that PP is a waste for that mileage. Yellow bottle looked fine for not knowing about the fuel. I don't think you have a fair comparison, here. Unless you know for sure fuel dilution was the same for both, you are comparing apples to oranges.

 

[Scottydog]

well this may be as good a head to head comparison as one can get. Same engine, back to back changes, engine reasonably broken in.

Yellow looked fine except for the viscosity degradation. Could trace fuel really do that much? Running what amounts to 20w oil at the end of yellow interval made me nervous...

 

[Triple_Se7en]

This engine prefers the yellow bottle -- outside of contamination from fuel. With a fuel number of only <.5, I think your flashpoint number of 316 is an analysis mistake.

 

[glennc]

Originally Posted By: Scottydog
Yellow looked fine except for the viscosity degradation. Could trace fuel really do that much?


I don't think so, which is why it looks wrong. I read somewhere recently what the typical flashpoint change is for a given percentage of fuel, probably in a link JAG posted or something like that. I don't remember exactly but it was something like 20C change in flash for 2% fuel... I could be off on that. But your flashpoint is off 70F (39C) or more if I recall correctly. That's a bunch. Either the fuel was higher or the flash reading was wrong, and the fuel being higher would explain the viscosity change to some degree. So you have two data points implying that fuel was higher than stated.

Perhaps something else could explain it?

At best it is an uncertain result.

 

[badtlc]

Only someone like Terry could tell you for sure about your fuel dilution. Blackstone uses open cup testing, not very accurate at all.

IMO, the change in viscosity AND the really low flash point make me think fuel is more than just a trace.

 

[Scottydog]

Here is Backstone's take on this...

"It's hard to say for sure what caused it to drop like it did. The fuel could have been a factor, especially since we didn't find any this time. The viscosity was certainly better this time and that's where synthetics shine."

You know for $20-25 in cost for PP every 6000 miles I'm going to go with the silver bottles and not worry about thinning oil...

 

[dave1251]

The drop to an 20 WT oil is common. It did not affect wear. I would not worry about it.