Walmart offers Mobil 1 Synthetic 5-Quart Motor Oil in 10 varieties for $23.88. Redeem this $12 rebate to cut the price to $11.88. Opt for in-store pickup to avoid the $4.97 shipping fee. That's $12 under our mention from two days ago and the lowest price we could find by at least $20. Rebate expires October 31.
Note: Although Walmart is not specified on the rebate, customer service states that this list is not all-inclusive, as it reads "some participating retailers".