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Shell Rotella T

R

rockjockphatts

NAXJA Forum User
Location
Minneapolis, MN
I'm gonna get yelled at, buy aw hell here goes nothing...

I've read the 17 page thread on 'your oil recommendation'-very insightful, however, I'm having a difficult time breaking out of my owner's manual mentality. It recommends no heavier than a 10W 30 oil, I'm seriously considering shell's rotella t, in a mixture of the synthetic and dino which amounts to 5w40 in one part to 15w40 in four (giving my 5 quarts which is usually what the ol jeep takes, any more and I'll add the syn which is the 5w40), this will give me roughly a 12w40 mix (I'd imagine close enough to the 10 weight recommended for summer temps) however the 40 is part of my reason for pause. It's a 98 stock 4.0L, 145,000 turns, on a hot summer day I'm looking at 10-20 psi at hot idle, I'm sure the 40 weight would bump that up, however at cruise power oil seems right in the middle of the gauge.


My concerns are: I know it's also SM rated for gas, but the fact that it's a diesel oil-is this going to cause any problems?

40 weight-should I be concerned?

I know it's oil, easy to change, but I don't want to booger up the old baby...
 
Rotella Oil

Rotella is a Diesel oil and has an additive that attacks your catalytic converter. the same additive is present in DELO etc. These are excellent oils, but not for gas engines


I never heard of anyone having problems with their XJ 6 cyl. running 10-40
 
For what its worth.....
It dont get as cold down here as where your at, but...
Iam running Castrol GTX 20/50 in my '99 with 174,xxx miles on the clock.
(some of 'em hard miles, iam not scared of the skinny peddle)
No ill effects, 35 to 40 lbs at idle, runs just like the day I got it.
Dont worry about the "40" except MAYBE during the cold months up there.
 
Re: Rotella Oil

DeathValleyPaul said:
Rotella is a Diesel oil and has an additive that attacks your catalytic converter. the same additive is present in DELO etc. These are excellent oils, but not for gas engines


I never heard of anyone having problems with their XJ 6 cyl. running 10-40
Click to expand...

What exacltly is this additive that attacks the cat? Rotella has alot of zinc in it. This is what a flat tappet cam needs the most in order to stay alive for a long time. The EPA has chopped the zinc levels (among other additives) in all other oils but diesel oil because it is an "environmental hazard".
 
I believe Rotella works best in classic cars where zinc (and leaded gas) were needed. Also, a injected engine's computer deals with alot of other factors that a carb engine can't. People were having issues with "wiping cam lobes" with newer oils.

I can't say anything about cat problems, but might be true.
 
Re: Rotella Oil

DeathValleyPaul said:
Rotella is a Diesel oil and has an additive that attacks your catalytic converter. the same additive is present in DELO etc. These are excellent oils, but not for gas engines


I never heard of anyone having problems with their XJ 6 cyl. running 10-40
Click to expand...

So are you saying that diesel vehicles dont have a cat converter? :bs:
 
Re: Rotella Oil

Only the more recent diesel models do.
 
According to all the machine shops and cam grinders you either run the rotella or you run an additive. Lucas and comp cams both have good additives but it is expensive it is cheaper to run the rotella instead of buying regular oil and running the additive. Now this is of course for a flat tappet cam engine like what is in our XJ's if you have a roller or overhead it doesn't matter. Alot of people are going to be really pissed off because nobody said anything. As far as the rotella you can get it in 10-30 which is what I run in my beast.
 
The additive in the Rotella T will only damage the newer Cats .Since no new XJ ,s have been built since 2001 there is nothing in the cat that will be damaged by any ZPD(ZZPD) or whatever additive.

Wayne
 
My dad's 96 F250 diesel had a cat on it.

I say HAD because my brother and I cut it off and basically straight piped it. It was so obnoxiously loud....

But anyway....
 
The 10 weight is the physical part of the designation, the 40 is the high temp extreme additive property. If you get any 10 - xo oil, it's 10 weight as far as the oil pump and viscosity is concerned.

In an older Cherokee, I'd run 10-90 if it was cheaply available. 10-40 is incrementally superior to 10-30 in my opinion, and running Rotella/Delo at 15-40 in a 4.0 with more than 150k sounds like a good idea. I doubt the 5w difference would amount to as much mileage loss as running gasohol.

Running a 5-20 synthetic, I'd just add ZDDP and call it good.
 
Are you sure it was a catalytic converter, and not just a secondary resonant chamber?
 
Cats came in and out for diesels over the years as emissions laws changed.

cats are nothing new on diesels. for dodge, 2nd gen 12 valves built after 1/1/1994 had a cat, but lost it again with the 24 valve. I believe the 24 valve had to add one later, but lost it in '03 again with the common rail. common rail had to add one later on too (2004.5 I believe). don't feel like looking it up the gory details though, i figure this is enough
 
Last edited:
aplatz said:
I believe Rotella works best in classic cars where zinc (and leaded gas) were needed. Also, a injected engine's computer deals with alot of other factors that a carb engine can't. People were having issues with "wiping cam lobes" with newer oils.

I can't say anything about cat problems, but might be true.
Click to expand...

What does it matter if it's a classic car or not? Any car/truck with flat tappets needs the additives to keep them alive. Doesn't matter if it's 40 years old, or 20. Also, what does the computer have to do with the oil you use?
 
ok, so I'm not really going to screw anything up...I've read, in different posts here, that the increased levels of phosphorus and zinc accelerate the wear of the catalytic converter, however, I like the idea of 1) a thicker oil, 2) an oil that protects my engine better, unlike modern SM grade oil, and 3) I want an oil with some detergent to help clean the engine (I know diesel oil has more detergent in it)

Bad idea?
 
rockjockphatts said:
ok, so I'm not really going to screw anything up...I've read, in different posts here, that the increased levels of phosphorus and zinc accelerate the wear of the catalytic converter, however, I like the idea of 1) a thicker oil, 2) an oil that protects my engine better, unlike modern SM grade oil, and 3) I want an oil with some detergent to help clean the engine (I know diesel oil has more detergent in it)

Bad idea?
Click to expand...

I just put the 15W40 Rotella in about 4000 miles ago after reading the thread many times. No issues. Purrs like a kitten.
 
I switched to Rotella at the same time I replaced my OEM Cat 20K(140K) miles ago. It has passed strict GA tests for 2 years with no indication of degradation of the Cat.
 
yea I looked around locally the last time I was doing an oil change and the only weights I seen were synthetic 5w40 and 15w40.I went with the 5w40 because my gut told me the 15w would be on the thick side for these Ohio winters.....
 
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