Hi. I was wondering what is a really good oil to run. I currently use Valvoline for no apparent reason and was wondering what others have been running. The only reason I am asking is because my brother tried the Valvoline 10W30 Extra Mileage oil and his engine started to tick. He has a 1993 Jeep Grand Cherokee. When he switched to Pennzoil 10W30 the tick went away. I don't use the high mileage oil and now am wondering if I should swicth brands. I don't like the color of Penzoil. It just looks funny to me. Thanks for any input on this. (I won't switch to Synthetic because of the price. It is about 2.5 times more expensive wher I live)