Hi.

I hope I'm not repeating any quetions that someone have already answered. I have searched the forum but didn't find anything.

My question is what grade engine oil should I use?

My car has 58k miles on it. In the summer time I use Mobil 1 10w-30 and winter 5w-30. Is that ok? The current temperature right now is ~10F and ~90F in summer.

The other question is some places say change your oil every 3k miles or 3 months. Why is it necessary to change the oil in 3 months if I only put 1k miles on the car?

I used to change it every 10k according to the FSS but since I find that unreliable I decided to change every 5k miles. Do I still have to change every 3 months?

Thanks for the help.