So I read a few posts about using rotella T6 oil in 4.0's. I live in Colorado where the winter is mostly cold (teens-twenties) in the morning with occasional negative temperature streaks. I also have a noisy lifter, just wondering what anyone would advise for or against

 

T6 and Wix filter. Don't look back.

Where in CO? Lived in Denver for 17 years. Really miss it.

 

Down in the springs, its changed quite a bit in my opinion, lots of out of staters

 

I run T6 all the time. I'd switch to 0W40 but its more dough. Mainly for that cold start up! Everything else seems fine.

 

T6 is currently what I'm running. Mostly for zddp additive. Might to switch to Mobil 1 next oil chance though. Still haven't decided. But as of right now I'm very happy with T6

 

Unless Mobil 1 has a diesel specific oil I wouldnt. I run delo 400 xle in mine personally.

 

I use t6, also. we frequently had sub zero temps the last 2 winters. even with 190k miles on it, my xj didn't make any funny noises on cold start up. it sat outside 12-14 hours a day while I was at work, it was nice and cold.

 

T6 and Wix go together like peas and carrots. Forrest Gump uses that combo in his 4.0.

 

Used T6 for over 1 year. It has good detergent and cleans well.
I switched back to Mobil 1 0-30 and picked up 1+ mpg and it has better load/wear characteristics.

 

T6 is the bomb.
For the lifter tick use Engine Restorer.

 

5w-40 or 15w-40?

 

Winter or summer?

 

I think t6 is only available 5w-40.
It's good for cold or hot weather.