what did they do to our cars gas tanks

felecia187 with today's cars you can't fill them past the first click , you can't drive past the quarter tank before it is remanded that you put more gas in them , now with the older cars some have a vacuum gas tank , this mean you have a gas cap that does not let air into the gas tank or out , now on hot days you gas will expand and the vapors will help your car to get at least 30 extra miles to a tank of gas , in today's cars you don't have a vacuum tank and your gas cap dose let air into and out of the gas tank , the reason for this is in the new cars the gas pump which is in your gas tank is sitting upright , now in the older cars the gas pump is laying down in the gas tank , now gas in both new and old , use the gas in the tank to stay cool this helps to stop your gas pump from burning out , old gas pumps cost under $ 100 well gas pumps for your new car can cost way way over $ 100 , so which is the better the old vapor gas tank and cap , or the new ones , well when you use gas to drive you are not burning the liquid gas you are burning the vapors because the gas it self dose not burn , so a pressured tank has a big advantage over the new ones more fuel economy , the gas that comes out your tailpipe is the gas that has not turned to vapor yet yeah you just wasted some of your gas out the tailpipe , about % 40 worth , so which is better the old way of course , now if you could turn all the gas in your gas tank to vapor you would get about 200 miles to the gallon , and you would not wast anymore gas out your tailpipe and this would be a lot better for the environment , so as you see some things should be left the way they are . enjoy .