A troy pound is equal to 12 troy ounces and to 5,760 grains, that is exactly 373.241 7216 grams. Troy weights were used in England by jewellers. Apothecaries also used the troy pound and ounce, but added the drachms and scruples unit in the Apothecaries' system of weights.
Depends on the API gravity of the gasoline, which varies by grade and refinery. Usually, regular unleaded gasoline has a gravity of around 58 and a weight per gallon of 6.216 pounds per gallon. Premium gasoline may have a gravity of 54, or 6.350 pounds per gallon.
Therefore, to calculate the amount of CO2 produced from a gallon of gasoline, the weight of the carbon in the gasoline is multiplied by 44/12 or 3.7. Since gasoline is about 87% carbon and 13% hydrogen by weight, the carbon in a gallon of gasoline weighs 5.5 pounds (6.3 lbs. x .87). We can then multiply the weight of the carbon (5.5 pounds) by 3.7, which equals 20 pounds of CO2!