What is the consensus on Chevron 10W-40 -- most people beat up on 10-40 weight oils here but Chevron is a good formulation and in the West Texas heat -- I am considering a little thicker oil than than the 10W-30 Chevron I am running now -- Checkers has it on sale again this week for .99/quart plus a rebate - I need to buy my oil for the summer soon. Thanks.