Gas pumps typically never provide the correct volume of fuel you have paid for due to a number of variable that most test methods are unable to correct for. The biggest one is vapour loss – which is why many governments around the world are beginning to outlaw open neck prover cans as a valid test measure. Another huge issue is temperature – specifically if you calibrate a gas pump on a hot day one time, and then on a cold day the next; your results will be very different.
Temperature correction at the gas pump to 15C, is mandatory in the UK, Canada and Australia. But in the USA it is a free-for-all, which is why “hotgas” is such a huge issue.
So if you are in America – BUY YOUR GAS ON COLD DAYS!! In the Summer months, buy in the early early morning when it is cold. Never buy your gas in the afternoon in the southern states unless you like paying extra for your fuels, a lot extra.
Dennis Oberdove says
Hi I am interested in purchasing a calibration system. Please call me at 440-773-4373. Thank you