Say you have a PP , M1 or Valvoline synthetic 5W30 D1/Gen 2 rated oil versus the same brand series synthetic 10W30 : What would I be giving up (if anything) in the way of protection or other key criteria if I use the 10W30 without the D1/Gen 2 approvals ? ... Is an oil company going to spend the money and time to make the 10W30 formulation that much different from the D1/Gen 2 rated 5W30 ?