Royal Purple 20w50 or Rotella T5 15w40

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Curious to know if anyone has had prior experience using royal purple 20w50 (or RP in general)..OR..Rotella T5 15w40. Will pick one for my 87 SDL. On the front of both cans it says it can be used in diesel engines. Is there a better choice? Appreciate the info.


Cheers
 
Rotella T5 hands down! and we sell RP here, Overated indeed. Im in the Engine Building for endurance,and Engine Dyno Business. I study the results of the engine teardowns,of thousands of engines. Tip of the Day: You might just go buy some Mobil 1, 15w- 50, and sleep well.
 
Thanks for the feedback Gun. Funny you mention M1 15/50...that's what's being used now and the report from Blackstone mentioned that--albeit barely--the viscosity was a little low for a 15/50 grade. It also mentioned a significant amount of iron, so I wanted to look around at some different products. Another question, is there noticeable difference between the T5 & T6 grades?

Looking for something that will last. The car will sit from January to late June, then I'll be driving it out to Arizona and will be there for 4 months (all through that Arizona summer). Never lived there but I know it gets HOT!!
 
Rotella or M1 15w-50 - either would do fine. Both are good products.

You could maybe run the M1 a little further before change, but heat is nasty, so I'd do the Rotella and change it again mid-summer. Oil's cheap. Engines, not so much...
 
Thanks Broc

Great point on the engines!!
grin.gif
I'll wait and see what this next report says about the oil sample (not sure if you read my second reply about it being a little less viscous) but I'm leaning toward the Rotella. I'll change it out around Christmas and should be good till June.
 
Is RP just geared for other types of engines? I met a few guys at the shop that--while they didn't think negatively of RP--also recommended as a first choice Rotella,Delo,etc..

I'm just really curious about different oil types and why ppl recommend one over the other. Although I know when it comes to oil its pretty much a "tomato-tomatoe" discussion. Probably should've studied a type of mech engineering :-/

Cheers
 
Originally Posted By: HerrDiesel
Is RP just geared for other types of engines? I met a few guys at the shop that--while they didn't think negatively of RP--also recommended as a first choice Rotella,Delo,etc..

I'm just really curious about different oil types and why ppl recommend one over the other. Although I know when it comes to oil its pretty much a "tomato-tomatoe" discussion. Probably should've studied a type of mech engineering :-/

Cheers


RP has oils for all types of gasoline or diesel engines. It's just they are more known in the racing/performance arena than typical commuter/family, commercial/farm truck or tractors (both kinds).
 
Originally Posted By: HerrDiesel
Thanks for the feedback Gun. Funny you mention M1 15/50...that's what's being used now and the report from Blackstone mentioned that--albeit barely--the viscosity was a little low for a 15/50 grade. It also mentioned a significant amount of iron, so I wanted to look around at some different products. Another question, is there noticeable difference between the T5 & T6 grades?

Looking for something that will last. The car will sit from January to late June, then I'll be driving it out to Arizona and will be there for 4 months (all through that Arizona summer). Never lived there but I know it gets HOT!!


Post the uoa of the 15W50 in our uoa section here.
 
T5 is a semi-synthetic, and T6 is a full synthetic. I tried RP once in a car, and didn't think it was anything special. Not bad, but not a revelation. The Rotella products are designed for a diesel, and have proven themselves around the world. It's my vote.
 
Originally Posted By: BobFout
Originally Posted By: HerrDiesel
Is RP just geared for other types of engines? I met a few guys at the shop that--while they didn't think negatively of RP--also recommended as a first choice Rotella,Delo,etc..

I'm just really curious about different oil types and why ppl recommend one over the other. Although I know when it comes to oil its pretty much a "tomato-tomatoe" discussion. Probably should've studied a type of mech engineering :-/

Cheers


RP has oils for all types of gasoline or diesel engines. It's just they are more known in the racing/performance arena than typical commuter/family, commercial/farm truck or tractors (both kinds).


Got it..guess it just boils down to application.
 
Originally Posted By: Garak
You've probably seen how they now have a separate "commercial HDEO" line, which coincided nicely with them getting a CJ-4 lubricant on the market.


yea..looks like RP Duralec is really the only diesel rated oil in its lineup and is really intended more for big trucks and tractors. Although, I wonder if the application design could be used for my car. Meaning..Is there a difference in using oil that's labeled "Heavy Duty Diesel" vs. "Light Duty Diesel"


Originally Posted By: aquariuscsm
Originally Posted By: HerrDiesel
Thanks for the feedback Gun. Funny you mention M1 15/50...that's what's being used now and the report from Blackstone mentioned that--albeit barely--the viscosity was a little low for a 15/50 grade. It also mentioned a significant amount of iron, so I wanted to look around at some different products. Another question, is there noticeable difference between the T5 & T6 grades?

Looking for something that will last. The car will sit from January to late June, then I'll be driving it out to Arizona and will be there for 4 months (all through that Arizona summer). Never lived there but I know it gets HOT!!


Post the uoa of the 15W50 in our uoa section here.


Sure...i'll dig through my inbox and put it up.


Originally Posted By: 2cool
T5 is a semi-synthetic, and T6 is a full synthetic. I tried RP once in a car, and didn't think it was anything special. Not bad, but not a revelation. The Rotella products are designed for a diesel, and have proven themselves around the world. It's my vote.


Thanks 2cool...that seems to be the consensus. I'm leaning toward Rotella, the base had some on sale as well so even better! :)
 
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Originally Posted By: HerrDiesel
Although, I wonder if the application design could be used for my car. Meaning..Is there a difference in using oil that's labeled "Heavy Duty Diesel" vs. "Light Duty Diesel"

The short answer is that there is no difference. It gets complicated, though, if you're talking about a newer automotive diesel engine with emission protection, require something like a dexos2 ACEA C type oil versus a CJ-4 E7, E9 type lubricant. Take an old diesel like an early Powerstroke, and there would be a wide variety of lubricants one could use, even ones that would be far too expensive for the application.

For your Benz, any CJ-4 HDEO lubricant would be more than sufficient. Personally, I'd prefer the 15w-40 HDEO over any 20w-50, since the latter doesn't have a lot of approvals and has little guarantee of anti-wear levels, unless you are getting a boutique like RP.
 
Originally Posted By: Garak
Originally Posted By: HerrDiesel
Although, I wonder if the application design could be used for my car. Meaning..Is there a difference in using oil that's labeled "Heavy Duty Diesel" vs. "Light Duty Diesel"

The short answer is that there is no difference. It gets complicated, though, if you're talking about a newer automotive diesel engine with emission protection, require something like a dexos2 ACEA C type oil versus a CJ-4 E7, E9 type lubricant. Take an old diesel like an early Powerstroke, and there would be a wide variety of lubricants one could use, even ones that would be far too expensive for the application.

For your Benz, any CJ-4 HDEO lubricant would be more than sufficient. Personally, I'd prefer the 15w-40 HDEO over any 20w-50, since the latter doesn't have a lot of approvals and has little guarantee of anti-wear levels, unless you are getting a boutique like RP.


Hmm..interesting..

I also noticed your comments on a another thread in regards to Duralac Ultra & Super 15w40(CI-4/CJ-4)..so i kinda understand what you mean. I guess CI-4 is slowly being phased out?? I'm not that "old school" so i'll roll with the CJ-4
smile.gif
 
I'm surprised than any CI-4 or CI-4+ lubes are left in North America, honestly. Obviously, some have an interest in them, and boutiques do fulfill those interests quite often; that's what they do after all. CJ-4 is the current diesel category and does very well. Imperial Oil (our XOM) doesn't have any of their legacy products listed on their sell sheets. I even tried to get a CI-4+ 5w-30 from them only a couple months after the CJ-4 rollout some years back, and it was already long gone.
 
Originally Posted By: Garak
I'm surprised than any CI-4 or CI-4+ lubes are left in North America, honestly,,,


Im not into the CI vs CJ thing but I have noticed, the 20/50 C oils seem to be CI4 rather then CJ4.
I know not why, dont care since my motorcycle is happy with anything at Ch4 and higher.

Amsoils 20/50 is also CI4. Heck, Im just glad to find a 20/50 or 15/50 C rated oil. Kind of strange you can buy S rated oils in all flavors, but not C.
 
Im not sure why anyone would use Royal Purple, other then it comes in a purple container and to me, the only thing good about it. :eek:)
 
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Originally Posted By: alarmguy
Im not into the CI vs CJ thing but I have noticed, the 20/50 C oils seem to be CI4 rather then CJ4.

Perhaps if nothing is calling for a CJ-4 20w-50, there would be no reason to make such an oil. Heck, plenty of 20w-50 oils don't even claim a long obsolete C spec, like they used to.

Originally Posted By: alarmguy
Kind of strange you can buy S rated oils in all flavors, but not C.

Well, it's not surprising given what CJ-4 actually calls for. You need an oil with a minimum HTHS of 3.5, so anything that has an ILSAC rating is already disqualified, and that's not even getting into additive levels.
 
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