My youngest daughter just acquired a Wranger w/the 3.6L Pentastar engine. While under warranty, I'll use 0w-20 oil. (Not a fan, but from what I've read this newest motor version was recommended to use this oil not just for the us market but globally.) So...I'll do an oil/filter change @ 1k using Pennzoil Full Synthetic. (Non-Natural gas to oil conversion.) The reason is this oil has the lowest pour point (-51) and higher viscosity numbers @ 40/100 degree C than the "Platinum" Pennzoil 0w-20. Also, the MRV is the lowest of all the Pennzoil 0w-20 oils. Sounds like a very decent oil all things considered. I may exclusively use this oil while under warranty and then later on use my clearance Castrol Extended 0w-20 oils. Anyone have experience w/this oil so should I just go w/the Ultra? Thanks for your thoughts!