Amazon offers the Pennzoil 5W-20 or 5W-30 Ultra Platinum Full Synthetic Motor Oil 5-Quart Jug for $12.47, via the steps below. Plus, Prime members bag free shipping. That's $3 less than what you'd expect to pay for these at a local retail store. Deal ends June 30. To get this:
  1. View the 5W-20 or 5W-30 jug for $24.97
  2. clip the $2.50 coupon on the product page
  3. redeem this $10 mail-in rebate for a final price of $12.47
Note: It may take up to two months to ship.

Update: This is now available for Prime members only.