synthetics are mroe for extended oil change intervals. whe ni first used synthetic in my 95 neon, had 60,000 miles onit, my engine laked bad! had a new real main seal put it, and the oil eventually came out the vlave cover gaksets and leaked past my oil pressure snder, all of which still kinda leak, and are all new and have been re-seald by mechanic. synthetics only clean so much too. plus, theirs no real hard evidence, showing synthetic made an enigne last longer, than an engine on dino. jsut select a good brand dino, havlline, mobile, motorcraft, pennzoil, stay with your change intervals, usually every 3 months or 3,000 miles adn you should do fine
however! stay away from fram oil filters, their junk.