Walmart has the 5-quart bottle of Mobil 1 5W-30 Extended Performance Full Synthetic Motor Oil for $9.37 (27.47 – 4.10 instant savings – 15 MIR) for a limited time. Shipping is Free for Walmart+ Members or pad your order to $35 or more and score Free Shipping. The $15 mail-in-rebate ends September 30, 2021. Limit of 2 rebates per household.