Walmart continues to offer Mobil 1 Synthetic 5-Quart Motor Oil or Mobil Super 5-Quart Oil in several varieties from $5.98 after this mail-in rebate. (The starting price and rebate amount vary based on the type of oil you buy.) Opt for in-store pickup to avoid the $5.97 shipping fee. That's tied with our mention from a week ago as the lowest price we've seen for any Mobil 5-quart oil. Rebate ends 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". Also, Amazon offers many of these items for the same price for Prime members.