I have used synthetic for as long as it has been on the market. Originally, for the fuel mileage, which I carefully tested and documented. As more syn long-chain polymiers were addeded to conventional, the mileage advantage largely disappeared. Now I use it mostly because an a non-carbon, I feel that it gives me better protection than conventional petroleum based products, and does not seem to break down into filter clogging sludge as bad as conventional oils. But, that's just my opinion, and I urge others to do as they feel best. I know lots of folks that will only use a particular brand or type, and will never even consider using anything else.
