any comments on royal purple 15-40 for diesels.
royal purple ?? any comments
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Royal Purple works great in diesel engines. I think there are other oils that are less costly that will do the job just as good. JMO
Royal Purple UOA
Royal Purple UOA
I used it one time and that will be my last. First let me say that it was one of my most necessary requirements of any oil that failed; that is breaking down when hot. My normal "hot" oil pressure is around 62#. With the RP it dropped as low as 55#. Hot idle is usually 27or so. It would drop to 19# with RP. This was in July pulling 25K# + up mountains and the like. I changed it back to PB Extreme and the pressure went back up. I did not change the filters when going back to valvoline PB. Just to eliminate the possibility that it was the filters. So after satisfying myself that it was the oil, the Oilguard and full flow as wlll at the oil was changed, and this time to Rotella T Syn 5w40. Have always used the PB but the local NAPA has stopped carrying it. So will stay with the Rotella. In addition to that my oil pressure at cold start would be over 100#. Made me think it was 50% Lucas.
My question is: did your wear metals increase with the 7 psi loss when the oil was hot? I had absolutely no increase of wear metals using Royal Purple. That is why I posted the link to my most recent Used Oil Analysis.
But as I originally stated: I think there are other oils that are less costly that will do the job just as good. JMO
But as I originally stated: I think there are other oils that are less costly that will do the job just as good. JMO
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Why is low oil pressure a concern? If pressure is the result of resistance.. and viscosity is the fluids resistance to flow, then a lower oil pressure would indicate that the oil had less resistance to flow. This means that more volume was likely being circulated in the engine.
As Vetteman asked, was there any indication that the RP provided inadequate lubrication? That is the only way to tell if the oil actually failed to perform its task.
All engines have a design parameter for oil pressure. The observed lower pressure of 7-8 PSI may have still been well within the design parameters of the lubrication system. Pump volume, lifter/plunger bore clearances, and orifice capacity have all been factored with regard to the amount of volume and resistance a circuit needs.
I'd love to see some analysis data with regard to the lower pressure engine. I have also wondered what the results were when pressure was at the border of the low pressure side.
As Vetteman asked, was there any indication that the RP provided inadequate lubrication? That is the only way to tell if the oil actually failed to perform its task.
All engines have a design parameter for oil pressure. The observed lower pressure of 7-8 PSI may have still been well within the design parameters of the lubrication system. Pump volume, lifter/plunger bore clearances, and orifice capacity have all been factored with regard to the amount of volume and resistance a circuit needs.
I'd love to see some analysis data with regard to the lower pressure engine. I have also wondered what the results were when pressure was at the border of the low pressure side.
I know my years worth of running Royal purple Long Rider 15w-40 in my Cummins N14 produced horrible UOA's. I personally would never touch that stuff again.
Hammer
Well I knew I'd get flamed over that
. No oil analysis. The pressure drop was important to me because it was sudden and directly related to changing brands of oil. T he same thing happened with the use of Amso 5w30. Got a quick, expensive flush! Another thing that bothered me was that the oil (RP) seemed to be thicker when pouring; and it was because the cold start pressure would be close to 95# in the summer. Today, and 30* cooler it is 70# cold start idle. So there was just too much difference from other oils for me to continue to use it. The Vavoline PB and Rotella T put it right back where it had been for 125K miles. The Royal Purple may be the best of all oils. However, my peace of mind does have some worth, and when dealing with a $12,000.00 engine replacement it was not too difficult to change oils again. And yes the pressures both high and low were within Cummins specs. They say that the min at hot idle should be no less than 11psi, and not less than 35 at 2000 rpm.
Not a problem, just hoping. We had a guy use Royal Purple and his Vis went down slightly, but his wear metals were great.
I agree, piece of mind is worth more to me than anything else on my vehicles.
Acilles
what about SCHAEFFERS..
ps: you know one person to ask would be the analysis lab guys! don't you think they would have a little insight??
what about SCHAEFFERS..
ps: you know one person to ask would be the analysis lab guys! don't you think they would have a little insight??
I think that you will find that Schaeffer's oils consistently turn out good oil analysis, even on extended OCI, and the price is decent if you keep it in the engine long enough. Can't say for RP- never tried it yet.
Achilles, you should become the new site sponsor for Royal Purple...er, maybe not since you are overseas.
I think what you are referring to is that Cummins a few years ago did not approve of any oil using powered moly in their oil. As we know, most all oils now use liquid moly and are no problem. Royal Purple is one oil that contains moly, but it is liquid. Also Royal Purple 15W40 is API Approved.
Use it if the price is right.
Use it if the price is right.
RP V. Schaeffer?
whom carries moly in the oil, and is that an issue at all?
Schaeffer gets really good press here on the board. Granted I have RP in my Volve D24, but we are operating at -35 F. right now, and as I resolve problems I have with my D24(its new to me), none of them seems traceable to the RP.
Nick
whom carries moly in the oil, and is that an issue at all?
Schaeffer gets really good press here on the board. Granted I have RP in my Volve D24, but we are operating at -35 F. right now, and as I resolve problems I have with my D24(its new to me), none of them seems traceable to the RP.
Nick
59 Vetteman wrote:
There, I said it for you. Somebody had to.
Will you please quit trying to be so unbiased towards Royle Purple! You know you think that RP is WAY over priced and is the primadonna of synthetic oils!
There, I said it for you. Somebody had to.
[ January 19, 2006, 12:06 PM: Message edited by: 59 Vetteman ]
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