Well so much for trying Maxlife in my 11yo Grand Cherokee. Many of you know by now that I retired it as a daily driver and was considering a switch to a HM dino or blend like Maxlife changed every 6 months...but I was at wally world and I could not help myself but to buy a jug of M1 HM 10w30 again...After 8yrs of nothing but M1, I could not betray my old Jeep...I will be doing M1 HM once per year or 3k (whichever comes 1st)...I am just gonna use up the Maxlife & Pennzoil HM in my other daily-driven Jeep w/ 4.0L motor...that way good oil doesn't go to waste...Although I do not have what I consider HM yet on that one, I would love to see if the Maxlife or Pennzoil HM helps the famous 4.0 rear main leak...