A "gallon" is a unit of measurement that is used to measure liquids, especially in the United States. It is equal to 128 fluid ounces or about 3.785 liters. Full definition
Millions of gallons of water mixed with sand and up to 300 tons of chemicals are then pumped into the well at high pressure to create breaks in the rock and release the gas. (mindbodygreen.com)
I have long advocated a big increase in gas taxes — add 50 cents per gallon per year for the next ten years. (bikeportland.org)
We must mention that in some test the Hybrid could achieve up to 34 miles per gallon fuel economy through city travel. (carannouncements.com)