I've been reading a lot of threads about guys using 15w-50 oil in SC's. I read an old thread today about only doing this in higher mileage SC's. My car has less than 30,000 miles on it. What weight oil do you guys recommend I use? Stick with 5-30, go to 15-50 or something in between? What about 0-40 Mobile 1? The car gets parked in the winter, but it may get driven on some colder days because I live in PA. I'd appreciate any advice.