Walmart continues to offer the Mobil 1 10W-40 High Mileage Full Synthetic Motor Oil 5-Quart Jug for $25.47. Opt for in-store pickup to dodge the $5.99 shipping fee. That's tied with last week's mention and the lowest price we could find by $11 today. It reduces deposits and sludge, conditions engine seals, and provides wear protection.