I’ve been running Rotella in all my RRC/D1/D2 for years and years and years, heck I even ran it in both my 05 Jeep Wranglers with the 4.0L. I never had a Cat or O2 failure due to the oil!!

I tried some Valvoline 10w40 Multi-Blend oil & I was not impressed at all.

The oil debate is like a political debate & to each their own, but in TX I swear by Shell Rotella 15w40 oil. I’d never run an oil any lower than 10w40 unless I lived up north where the extreme temps tip the other side of the scale.

 

Rotella T4 15w40 works all year in Seattle.

 

What I haven't seen mentioned yet is that a true "knock" will not be fixed by changing oil viscosity.

 

I mean I understand that... I’m just trying to get my compromised engine to last a bit longer.

 

15-40 Rotella in South West and South East.

 

Got 3 gallons of rotella T4 and a new genuine filter.... how many quarts do you all use. I’ve heard between 6-8 so just wanna make sure.

 

6 1/4 or 6 1/2qt depending on the filter used (long/short).

 

Okay just added about 7qts of rotella T4 minus what was lost in the mid change oil filter fill and swap. This is the result ...

 

Synthetic has smaller molecules and will leak in these old engines with sloppy tolerances. I've tried many different weights and types and IMHO, the best compromise is 15w40 dino. 20w50 Valvoline Racing if it's really worn and in warm climate but I noticed worse economy with that because I have a short commute and it doesn't get up to temp fast enough here in the northeast. Fine on trips tho.. of course it's all in your perception unless you do tear-downs and mic everything for wear after every oil change. And motor oil is, after all; motor oil

 

When did rotella shed its S rating? Its no longer on the container