In my 1998 Jeep Grand Cherokee 5.9L, I'm currently running a gallon of 15w40 Valvoline Maxlife HDEO and a quart of Mobil1 HM 10w40. That would be WAY too heavy for most, but since I've been learning here, I figure the 15w40 HDEO would be good for my Jeep considering the 5.9 variations run hot and I live in FL. Not to mention I have a leak free running setup at 280K miles.
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