5 Quarts G Oil Free After Mail In Rebate! This post may contain affiliate links. Please see my full disclosure policy for details. August 23, 2011 23 Aug Pin0Share0TweetGoogle+0shares Buy 5 quarts of G Oil from Walmart and send in this mail in rebate to get the 5 quarts of G Oil free! (Up at $26) To mail in this rebate you will need to buy the oil by 9/17/2011 and postmark the envelope by 10/1/2011. Thanks, The Thrifty Couple!