After visiting this site for about a month, I have setup my strategy on doing an AutoRX cycle on all 3 cars over the summer. I have a 92 Cherokee 4.0L 155k (sludge monster getting a double dose of ARX), 04 Dodge Neon 2.0L 18k, and a 02 PT Cruiser 2.4L (non Turbo) 54k. I have ordered the AutoRX for all, and have stocked up on Havoline dino and PureOne's for each cycle. After the cycles, I plan to use MaxLife 5w30 in the Jeep, and put the two Mopars on Pennzoil Platinum 5w or 10w based on season (the PT did not like M1, hence the choice for PP). My question is, should I take the Mopars directly to the Full Synthetic right away, or run a Semi Synthetic to transition for one OCI? I plan to do an AutoRX maintenance for all 3 on each OCI after the rinse, but I didn't know if going from the dino directly to synthetic would affect the seals or "shock" the system in some way. Any advice would be appreciated....