Question: how to calculate how much gas you have used?
Answer: To work out how much fuel you will use in total, divide your distance by 100 (because we are looking at the fuel use every 100 km), so: 295 / 100 = 2.95 and then multiply it by you combustion, so by 8: 2.95 * 8 = 23.6 . Now you know that you will use 23.6 liters of fuel.