Well guys I want to switch over to Pennzoil or Quaker State High Mileage...would it be safe? Truck has over 220k now on a chevy 5.3 l33! Right now I'm using maxlife 5w30 and a Bosch filter..is if safe to switch to Pennzoil? I want to give my motor a good clean out! I drive short trips averaged 10 miles a day, lots of stop and go traffic!