Walmart continues to offer Mobil 1 Synthetic 5-Quart Motor Oil or Mobil Super 5-Quart Oil in several varieties from $6.98 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 charge. That's tied with our mention from two weeks 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.

Update: Prices now start from $10.61 after the above rebate.