I used synthetic for a couple of changes a few years back, but found absolutely no difference in performance so I went back to dino juice. Dunno if I can say the brand here, but decent quality stuff, and I'm pretty good about getting the oil changed every 3K to 4K miles. Going on 130,000 miles and so far zero defects in the engine compartment.The 1.8 ZZ base engine really doesn't rise to the level where it will kill conventional oils unless you try to drive it like Parnelli Jones.Of course, this conversation has been beaten 60 feet into the ground in other threads here.