familytime

There's been other treads about oil usage in the 3.8 when using 5w-30 as the factory recommends.I've was losing about 1qt to 1-1/2 qt per 3000 mi.I've been running Shell,Rotella T 15w-40 for the last 50,000 miles.Yes its a diesel oil,but have not lost a qt.runs quieter than before.

JKlad

Ok, thought I'd post another update on my progress after switching to 15W40, as I just did another oil change yesterday (as I do them every 3500miles it would normally have been two in this timeframe since I made the switch however the Jeep was laid up for a few months while I was interstate for work). 6 quarts went in last time, & I drained 5.5 quarts out after 3500 miles, but in hindsight I didn't drain the filter & measure this as well so all up it appears the motor used little if any oil during this period. Also pulled the PCV tubing as well & it only had a light dusting of oil vapour in it, & wasn't dripping with oil as it was when I was running the 5W30.

Motor is still running smooth & stong and no longer pings noisily under load and is quiet and without the coarseness and ticks/rattles/knocks that it had when running on the thin oil specified by Chrysler. All in all I'm very happy with the results from running this motor with approximately the same weight of oil that it was originally designed for.

keithsfd7

Subscribed; definitely going to try the thicker oil, bought my 07 new with 11 miles on it, been using 1qt per 1000 miles since 1st oil change, Chrysler feels that this is allowable. Lol

XBlacky08X

I run 5w-30 winter, and 10w-30 summer. No issues and does not burn a drop of oil.

KDBinAZ

Any variation in mpg with the thicker oil?

fstopme

Ditto!

JKlad

I have seen no noticable long-term difference whatsoever. Chrysler specifies the thin oil as it achieves slightly better results (typically <1mpg difference) in the 36hr bench test that is used as part of Chysler's CAFE accreditation, as this tiny improvement helps them comply. Real world results involving every day driving typically show little if any measurable improvement in mileage using 5W20 over oils of slightly higher viscosities.

OH9JK

good reading...

h t t p://www.upmpg.com/tech_articles/motoroil_viscosity/

topher81

just bought an 07 with 75k on it and it's pretty smooth but still feels a bit sluggish even with a superchips flashpaq on it. oil might make a bit of a difference!!!



definately subscribing...

wralston89

Made this change to 15w40 shell feels great and definitely quieter ... Was tentative but so far it feels great did a little wheeling today and did well