Isn't rotella made by shell? I was under the impression it was all diesel oil

 

Yes and yes it is.

 

Previous owner ran Mobil1 5w30, I ran that for one changed and switched to Rotella T6 5w40. No issues aside from the normal lifter noise and valve cover gasket on my 1999 with 336k KM.

Rotella comes in a lot of grades, weights, and blends. The T6 5W40 is a full synthetic and comes very highly regarded in many communities (from severe duty diesels to wet-clutch racing). It also bears the following certifications:

API Diesel Specification:
CJ-4, CI-4 PLUS, CI-4, CH-4, C4

API Gasoline Specification:
SM, SL, SH

Misc Specifications:
ACEA E9; Caterpillar ECF-3, ECF-2; Cummins CES 20081; DDC 93K218; Ford WSS M2C171-E; JASO DH2, MA; Mack EO-0 Premium Plus; MAN 3275; MB Approval 228.31; Volvo VDS-4

The other Rotella grades have their own certs too. Note that the 4.0 is an API SL oil. SN is the latest badge and requires a reduction in ZDDP.

Sorry to sound like a sales pitch but there's some actual facts up there for ya. It's diesel-oriented but certified for use in many gasoline engines.

As for the usual reasons for running synthetic, I don't practice really extended oil changes, certainly nothing longer than what you can do with a modern conventional and the larger-size oil filter. Most 4.0s at this point probably need a whole new set of O-rings and valve seals before playing with the long oil change intervals... contamination from combustion byproducts is the usual issue but you can't filter out fuel that's dilluting the oil. I like synthetic for the lower startup viscosity and strength, but I specifically went for the Rotella for the additive package and on sale it beats any other synthetic I'd pour in lol

 

One more ? Is the t6 the full syn rotella? What filter do you run?
We have similar mileage..just curious.

 

Yea it's full syn. I run the m1-301 oversize filter

 

Is that a mopar filter? I just bought a 090 (iirc) just havent got around to changing the filter.

 

M1-301 is a Mobil1 unit.

Cross-reference for oversized filters:

FRAM PH8A
AC Delco PF2 (same OEM as FRAM)
Mobil1 M1-301
K&N Gold HP-3001 (M1-301 with a nut welded on)
Motorcraft FL1A
WIX 51515
NAPA Gold 1515 (rebrand WIX 51515)
Purolator L30001
PureOne PL30001

 

It comes in 15W-40 here its labeled HD Diesel.

 

There are three different rotella oils. Not just one.

 

I switched to good ol Walmart syntech 5-30 full syn with mopar 090 filters, available at walmart also. No drips ,leaks or low oil pressure. That was at 191,000. It gets good and cold here, I would hate to do a cold start up at 19 below with a 40 or 50 weight oil. Most engine wear is caused from poor lubrication at start up. I change mine at 3000 mile intervals. Flame on for the syntech,lol

 

The Super-Tech oil used to be made by Castrol but is now made by BP. Good stuff regaurdless.

 

I truly believe changing your oil and filters regularly is more important than what brand or dino or synth. And thanks, I meant Super-Tech. Not Syntech.

 

I agree! Very important to change regularly for a smoother, cleaner running engine.
I was just throwing the brand for people who turn down "store brands" thinking theyre lesser quality.

 

I use Castrol semi synthetic and I'm at 130,600. I haven't had any issues with the oil.