Why is it that if you are pumping yourself you can stop whenever you want with no problem, but if you pay first the pump slows down about twenty cents before what you paid for. What is the point of slowing down if you can’t go over the amount you paid for in the first place, who is this helping?
it slows down because it is easier for the flow of gas to come to a complete stop.
the gas station gives you exactly the amount of gas you paid for, to the penny. so the amount of gas flowing must stop on whatever penny that is. it cannot stop instantly, so it has to slow to a stop.
Why not?
Inertia???
-Dragwyr
“If God had meant for man to eat waffles,
he would have given him lips like snowshoes”
-Rev. Billy C. Wirtz
Um…No.
You ever notice when your tank is full? The pump stops instantly. So I don’t buy the inertia bit.
Or do you patronize only full-service gas stations?
Criminy.
The pump shuts off instantly because the fluid level backs up to the tip of the nozzle and creates a partial vacuum, triggering an auto-shutoff mechanism.
If you are fast approaching the $20 pre-paid limit and your tank is not going to top off to trigger the auto shutoff, the pump makes a decision to slow down as the last 10¢ dribble into your tank. It does this simply to avoid the posibility that a few extra ounces of gasoline might continue to spill out if the pump tries to slam the brakes on without slowing down first.
You might think it trivial for a station to go through all of that fuss to avoid giving you $20.01 in gas when you’ve only paid for $20 worth, but remember we’re talking about an industry that prices its commodity to the consumer down to the tenth of a cent.
When will all the rhetorical questions end?
Opus
I tend to agree on the shut off. I have seen some that don’t slow down, go over the prepaid amount. An yes, I go in and pay for the extra.
The pricing to the tenth of a cent is a maketing ploy, not a serious attempt at pricing. It always ends in .99, which is in small print when the price is advertized. I have never seen the price change a fraction of a cent.
But it can stop instantly, if you are planning to pump 7 dollars and can time it right you can stop Exactly on 7 dollars.
It stops instantly when your tank is full due to a nifty trick of physics, not because the pump itself electronically slams something shut.
I refer you to How does a gas pump know to shut itself off?
Essentially, when your tank is full, a vacuum is created in one portion of the miraculous pump handle that yanks the feed line shut abruptly. Thus, the instant cut-off. When your tank is not full, this doesn’t happen, so the pump slows down early (thanks to electronics, not physics) so that it can make a casual cut-off right at the moment your cash runs out.
OK, but is it absurd to assume that they could use electronics to invoke the shut-off that is normally brought on by physics?
It ain’t no pump, folks. Hasn’t been for something like 50 years. It’s a dispenser. The pump is way down there in the tank, underground.
Peace,
mangeorge
Teach your kids to bungee jump.
One them might have to cross a bridge someday.
Jeez people! The answer is yes, the pumps could stop right on the exact amount at least 95% of the time. But the gas stations err on the side of caution and always give them 10 or 15 cents leyway. Gas stations very often make little (sometimes no) profit off of gasoline sales. Just a few pennies per gallon.
I for one welcome our new insect overlords… - K. Brockman