part of this is thanks to the deals section at bobistheoilguy.com

autozone is currently selling castrol tection 15w40 for $6.99/gallon, which isn't bad for any modern non-fleet diesel engine oil. castrol currently has a rebate for which, if you purchase 3 gallons of Tection, will get you a check for $6 in the mail, theoretically getting you 3 gallons of tection for $15 dollars. 11 quarts of motor oil for $15 is hard to beat these days. rebate expires 12/31, autozone deal probably ends soon.


rebate coupon here
http://www.castrol.com/castrol/promo...tentId=7011757