Originally Posted by Rick Miley

3. Oil is a touchy subject on this board, and most people will tell you to do a search for information. But for this car in your climate I have no problem recommending Mobil-1 Truck and SUV oil (5W40) or Amsoil heavy duty marine and diesel oil (15W40). Do NOT use 0W anything. The regular Mobil-1 15W50 is a possibility, but does not carry the CG-4 or higher rating that is specified for this engine. I think the M-1 Truck and SUV has a yellow cap and can be found at Wal-Mart. If the Shell oil you mentioned is Rotella synthetic, it is not a "true" synthetic.