This isn't a post to debate oil brands or usage. If you use Shell Rotella T6 synthetic 05/40 motor oil I've attached a link for a 5 dollar coupon. I bought a 4 quart jug of T6 at Walmart about two weeks ago for 21 dollars. I followed the directions at the link for a 5 dollar coupon and the check came in yesterday's mail.http://rotella.shell.com/coupons-reb...Rvci5jZm0=Bill