from what ive read on various jeep forums, the 2007-2011 Jeep wrangler JK's with the 3.8 are notorious for burning oil, and my friends 2011 is no different. he has 19, 800 miles on it, and it was changed at 18,000 using RP 5W20 and a Bosch d+ filter. it never makes any short trips, he works a 14/14 schedule, its driven 550 miles one way every 2 weeks then 550 home. lets just say the oil always comes up to temp and viscosity, never sits up or gets short tripped. its burned half a quart in 1800 miles. Most of the guys on the forum say they see less consumption with a 5W30 or 10W30. Would anyone recommend using a 30wt oil while its under warranty?