I just purchased a 2003 E500 Sport. The owners manual does not stated the Oil weight or viscosity. It does state to use Mobil 1 synthetic, but not the weight, e.g., 0w-30, 10w-30, 15w-50, etc. Can any tell me what weight to use? I do live in the south where the coldest temp. would be 30 to 40 deg's. I will use the Mobil 1 or Redline synthetic oil.... any comments?