Walmart has the Mobil 1 5W-30 Extended Performance Full Synthetic Motor Oil (5-Quart) for a low $9.37 after $15 mail-in rebate (Details Here, Exp 9/30). This normally retails for $27.97, so you're saving 66% off with this deal.
Helps to protect your engine from the five factors that can damage engines over time
Helps to protect critical engine parts for up to 20,000 miles between oil changes
Controlling oxidation to prevent oil breakdown and maintaining excellent viscosity
Meets ILSAC GF-6 standards to help provide low-speed pre-ignition
Provides excellent internal engine heat protection (up to 500 degrees F) and low temperatures (to -30 degrees F)