I know this question gets asked alot, but I would appreciate the help. I've done some searching on the topic, but my eyes start to bleed after a while with all the info available, ha. I have a 2003 civic si which calls for 5w-20 oil. I am a little concerned that this is too thin of an oil to be using especially in the summer months. I live in NY so winter shouldn't be a problem, I think. I don't really drive my car hard, but it's still in the back of my head that 5w-30 would protect better in hot weather. Seing how the rsx-s with basically the same engine is recommending 5w-30 it makes me worry even more. Again I am a newbie as far as oil so I don't know if my presumtions are correct. Ok now for my next question. I'm wondering if synthetic would be worth it for me. So far I have 9,000 miles on the engine and I have been changing the oil every 3,000 with conventional oil. I don't mind spending the extra money on synthetic, but I would like to know the advantages and possible disadvantages if any. Thanks alot for any help.