[header] How to get free gas [title] Print out your receipts and check the pumps. [step] Some pumps don't give you what you pay for. If you want to get free gas, it's important to make sure that the gas you are paying for matches up with what is advertised. 
Sometimes the pumps can be miscalibrated, and if they are, you can get some extra gas for free. [substeps] Try filling up a container you're sure of the dimensions of, like a gas can, instead of your tank.