I just bought a Manual 97 Mazda Lantis 323 1.8L DOHC 16 Valve BP which in the USA seems to be labeled a Protege. I'll try and provide as much info as I can as per the sticky oil post. The head and rings were done on the car a few years ago. Previous owner says it was using about 4 liters of oil in six months without any noticeable oil leaks ( although when I checked the oil it looked over full ). There's no noticeable oil stains under the car when it stands for extended periods. However, after putting it up on a lift we noticed an oil leak bottom passenger side of the engine which I'm assuming must only act up when the car is running. Also some weird idle issues, but I don't think that's relevant to this ( correct me if I'm wrong ). Previous owner was putting some generic 20W50 oil in it, don't know what the original owner did. I live in a generally hot arid country ( might get down to freezing two weeks a year ) and do mostly short city drives. Autozone site recommends various 10W30's, but after reading the Oil University stuff I was figuring why not a 5W30? What's worth putting in; mineral, blend or full syn? I've seen a Prestone 5W30 syn blend oil which isn't too expensive, a full syn German oil which is three times the price, and I'm pretty sure I can pick up Motorcraft at the local Ford / Mazda dealership, but don't know how much it costs. One more thing, what's the deal with High Millage oils for older cars? Anything special about them that I should go hunting for one?