I just purchased a used 2003 boat with a Yamaha 200 HP HPDI motor. I was looking at different types of 2 stroke oils and found a very wide range of prices, anywhere from $21 per gallon to $40+ and higher per gallon. My question is what do most boaters use for oil and where is the best place to buy it? So far Walmart's $27 per gallon of Quicksilver oil seems to be the logical choice but they also sell Penzoil and Walmart's own brand for even less. Thanks for any advise a head of time.