I don't really think the i6 is going to be burning that much oil. 15w40 is overkill if you ask me. You're leaking some where.

 

I use it year round.

 

Yup. Just went out into the garage and changed the oil in my Comanche. Rotella and Wix.

 

I also use Rotella and Wix. Though I use 10w30 Rotella. Maybe you can get away with thicker oil in hotter climates. Can't imagine how my start-up would sound using 15w40.

 

I use 15-40. I live up in the mountains of Arizona a mile high. We see single digits in the winter and triple digits in the summer. Ever see this?





Jeep Engine Oil Viscosity

This was taken from pages 82 and 83 of the 1989 Chrysler/Jeep owners manual.

Selecting Engine Oil Viscosity

When changing or adding engine oil select the proper grade by using the chart on the following page. Select the grade that corresponds to the ambient temperature range you expect to encounter before your next oil change.

30*F to 100*F+ 20W-40 or 20W-50

0*F to 100*F+ 10W-30 or 10W-40

-20*F to 60*F 5W-30

 

It gets as cold as -22F here from dec to feb, she turns over awfully slow with 15w40 in her lol. When the temps come up I switch back to rotella

 

Makes sense.

 

I don't use Casrtol 30W on drill-bits or my hack saw blade. Doesn't cut well.
Haven't had a problem with a rod or a piston in well over 10 years.
Not for new engines, not for sub-freezing temps, but I really like the stuff myself. Runnen strong and supper smooth at 272K. Straight weight holds up. I'd use "multy grade" and change more often if I was somewhere a little colder!

 

This thread went from an oil leak to oil weight discussion.

I run Rotella 10w30. Winters we can see -digits, summers we can get triples for a few days. 10w30 I think is a good medium to run year round. I've lived in AZ as well. I don't miss those summers. Though we hit 100* with 90% humidity. Showers are frequent.

 

In my defense, the title is "burning a quart a week" not "leaking a quart a week", and he claimed no leaks.

 

Good point, but hey, since we need to wait.......

 

And what do you run in the winter months?

 

10w30