How much does 10w30 oil weigh?

The weight of 10W30 motor oil can vary slightly depending on the brand and formulation, but on average, it weighs about 7.5 to 8.5 pounds per gallon. Since there are 128 fluid ounces in a gallon, this translates to approximately 0.58 to 0.66 pounds per fluid ounce. For precise measurements, it's best to check the specific product's data sheet.