I finally find a perfect oil for my Jeep and it is essentially (for all practical purposes) discontinued. is there another oil that is as good and clean? Should I switch to Penn Platinum or is there a better oil that meets the Chrysler spec? I do go offroad and things get pretty hot at altitude, so I wanted a good synthetic. Crawling along steep slopes on hot days with little airflow heats up the engine and tranny pretty badly. Am really bummed that I cannot find PU...