I've been running Mobil 1 in mine (6000 mi. intervals) since I bought it with 48K on it. It now has 66K on it and I am in the middle of putting in a new cam and kit. I was amazed at how clean the inners were....no sludge, not even a thin coating. The parts I am replacing show almost no wear so, at least, the person that had it before must have changed the oil. I switched mine over directly, almost as soon as I bought it. The dumb Jeep dealer had put 10W-30 dino. oil in it and bragged to me about how they were doing me a big favor. I think I drove it maybe 200 miles and the MDS barely worked. I have another Hemi vehicle, so I knew how the MDS should work. After putting Mobil 1, 5W-20 in it, it started working much better. By the second change, the MDS was working as good, or even slightly better than my other vehicle. To answer your question though, many have reported that a good synthetic works better in the Hemi than a good dino. oil.
06 GCO, Dk Khaki, QDII, Flshing Hi 3rd Bk Lt, MDS "ON" Lt, Airtab Vortex Gens, Debadged, Fumoto Drain Valve, BT Catch Can, Chopped EGR Tube, SRT8 CAI, K&N Filter, Sonnax Trans Line Press Booster, SC Tuner W/Adv Trans Tune App, DS Tuner, Cust tubular hdrs w/3 in Magnaflow/Xlerator AP Exh Sys, Bilsteins, SRT Springs/Sways, Cust Eng Cvr, SRT8 frt/rear bumpers, FRI Sidewinder Cam/6.1 valvetrain, SLP 25% UD Pulley, BBK true 90mm T-Body, SOS Ign Coils w/.060 spark plug gaps, SRT Reps with 265/45&295/40X20's.