Talked my dad into using Rotella at the next oil change in his 5.7L Chevy in hopes of cleaning it out and freeing up a sticky lifter. He's been using 5w30 Valvoline dino in it since he got it 2 years ago and the oil change records which were all in the owners manual showed regular 4000mi changes on Quaker State 5w30 dino. It currently has 72K mi. This truck is used to pull a 23ft 2500lbs camper in the summer and rarely driven in the winter (he has a 90 S10 4x4 that he drives most of the time). Prior to him owning it, the previous owner was an older gentleman who used it to pull a 25ft 5th wheel camper. I may even be able to convince him to leave the Rotella in year round and just change it twice a year (since he puts less than 8,000mi a year on it). I'm assuming that most on here would agree that the Rotella would be a good oil for this application. Particularly considering the towing he does with it.