I am going to buy oil and I was wondering everybody's thoughts for oil for my truck. I have been having it changed at the Dodge dealer and they have been using 10w-30 I believe. What do think of me using 5w-30 for the 360cid engine? I will probably buy Penzoil or Mobile regular oil. It has been a good engine so far except it sucks gas like there is no tomorrow. I change oil about every 3000 miles. I am leaving soon to go buy oil so quick answers are great. Thanks for your ideas in advance, Wes