With the 2.7l motor the best advice i recieved from a Dodge/Chrysler shop foreman was to change the oil and filter EVERY 3,000mi. I now have 216,000k on my '98 Chryler Intrepid running on conventional oil..5w30 with Fram oil filter..and this motor still purrs like the day i bought it!

 

Guys check out auto rx that is the best solution and will be the most cost effective over the long run. I used auto rx in my 2.7 and it did make a big difference and now I'm using it in my 3.5. Just look at all the testimonials and before and after pics, you'll be shocked.