I there! I have a 2000 Grand Caravan, 21,000 miles on the 3.8-liter engine. The car has been with us since Sept. 2000. The warranty is over and I will not take it again for service to the dealer, as it is lousy and I'm not really sure that full service is given there. We have been putting regular dino oil, Exxon 15W-40 and changing it every 6,200 miles (that's 10,000km). Minivan is driven by my wife under heavy traffic conditions and steep grades going home. Would you recommend switching oils to Mobil 1 15W-50? I think Mobil 10W-30 is too low and this viscocity is not recommended in the manual anyway. I live in Mexico City and Mobil 1 is about the only synthetic available, with a constant supply. Shell and Penzoil also sell synthetic in department stores but supply is not constant, so there's a risk of not finding the oil for subsequent changes. Your comments will be very much appreciated.