Pump your gasoline slowly

[barryh]

For conversation only......

I have read and seen some info that claims in modern gas stations with equipment in good working order do not give you all the gas you are paying for...

The faster the pumps the less fuel you're getting.. many claim to take the extra 30 seconds and pump slower... Personally I can't stand those super slow pumps but......

There's some logic in principle but it may not result in significant differences in accuracy.

Petrol pumps have traditionally used a positive displacement type of flow meter. PD meters must have some small leakage (unmetered flow) so that at lower flow rates the leakage represents a larger percentage of the total. You would need to know the exact specifications of the meter to calculate whether pumping fuel at a slow rate had any meaningful benefit over pumping at a high rate.

For example the leakage rate through the meter might mean that it didn't record a flow rate of one drip per second but that flow rate is so low that it has no significant effect on overall accuracy at practical flow rates.

 

[north star]

This is my view \ opinion on the fuel pumping topic. Gasoline ( all grades )
are designed to release energy very quickly ( very high expansion rate of
the fuel ) when ignited in the engine cylinders. I believe that when gasoline
is pumped very quickly, that there is an amount of air being pumped right
along with the actual liquid ( i.e. - the pumps are designed to measure
volume and NOT weight ). If the pump handle is situated to pump the
gasoline liquid at a very slow rate, then there is less air being added in to
the mixture vs. the high flow rate otherwise. Slower pumping = less
expansion of the gasoline liquid, hence more liquid gasoline in my tank.

I always try to pump at the very slowest rate that I can. I have had customers
in line behind me become very irritated at my pumping method ( FWIW,
I ALWAYS carry a loaded & chambered pistol for anyone who wants to
present themselves as a very impatient jerk. ).

I am not an petroleum engineer or an expert of any kind. This is just my
opinion on the pumping.

I hope that there are some petroleum industry \ weights & measurements
experts who will chime in and provide some real, verifiable data \ information
rather than some questionable videos from YouBoob.

Thanks for reading!

 

[AZjeff]

Do you know my brother?

No but you talked about visiting him and you were thinking about moving here.

 

[DirtJunky]

that "free" ounce or two is yours, you paid for it. If others leave it in the hose, their loss.

 

[Mainia]

In Minnesota .5% of your pump purchase goes to Swiss Bank accounts. All 253 of them get % of the till. When you have a good thing going, you "step and repeat".

 

[Drifter]

Ours are, also. Once every 3 years!


My preferred (and closest) Shell station is associated with Rudy's Country Store & Bar-B-Que. Not only are they high volume, they are located very close to our city's police station. We don't have panhandling in my city, unlike the organized panhandling in Austin.

View attachment 329727

That looks to be the Round Rock location. At Old Settlers ?

 

[mk378]

New nozzles don't let you drain the hose after stopping the "pump". They only flow if there is pressure behind it.

Gas stations only have one pump. The thing next to each car is a "dispenser." It measures the gas going into the car from the central pump, it doesn't actually pump it.

"Accurate at any delivery or pressure" is the mantra. It used to be on a label on the dispenser.

If I could get gas for free at one drip per second yes I would stand there all day.

 

[CleanSump]

New nozzles don't let you drain the hose after stopping the "pump". They only flow if there is pressure behind it.

Gas stations only have one pump. The thing next to each car is a "dispenser." It measures the gas going into the car from the central pump, it doesn't actually pump it.

"Accurate at any delivery or pressure" is the mantra. It used to be on a label on the dispenser.

If I could get gas for free at one drip per second yes I would stand there all day.

Yes. Anyone filling a can on the ground should have noticed that when you release the lever, only a trickle comes out of the nozzle. And, when you pull the lever again, there's no split second wait because the hose it always full.

 

[y_p_w]

New nozzles don't let you drain the hose after stopping the "pump". They only flow if there is pressure behind it.

Gas stations only have one pump. The thing next to each car is a "dispenser." It measures the gas going into the car from the central pump, it doesn't actually pump it.

"Accurate at any delivery or pressure" is the mantra. It used to be on a label on the dispenser.

If I could get gas for free at one drip per second yes I would stand there all day.

Someone told my mother that water meters don’t turn if there’s a really slow drip. So for certain things she might just drip water in sink where it might take 60 minutes to fill up maybe a half gallon. I told her that it probably wasn’t happening like that, and what purpose would it serve?

 

[melk]

I always pump the gas slowly into my CRV because anything more than the lightest squeeze of the handle and it shuts off. Pretty sure it’s a saturated charcoal canister or collapsed vapor return hose

 

[tmorris1]

Only buy gas on cooler days that way you get more volume!!!

I don't think the ground temperature changes much. Even from winter to summer as deep as the tanks are

 

[tmorris1]

Someone told my mother that water meters don’t turn if there’s a really slow drip. So for certain things she might just drip water in sink where it might take 60 minutes to fill up maybe a half gallon. I told her that it probably wasn’t happening like that, and what purpose would it serve?

A gallon of water cost a small fraction of a cent...

 

[Zee09]

I filled up today and slow.....
No choice, I got one of those penny a second pumps

 

[headofthebored]

Who wants to stay at the gas station any longer than needed? Between the homeless bums asking for a handout,others willing to smear your windows for a couple of dollars,loud boom boom radios, people yelling and whatever else I'm in and out as fast as possible.

Hey now, homeless bum is a respectable, straight and narrow career compared to say... congressman.

 

[rstsco]

I filled up today and slow.....
No choice, I got one of those penny a second pumps

When I've encountered these, I stop filling as soon as I know I have enough to get to the next station.

 

[Zee09]

When I've encountered these, I stop filling as soon as I know I have enough to get to the next station.

Yeah I do that most of the time
But nowadays all we have are the constant top off folks jamming all the stations up.. it sucks

 

[rstsco]

Yeah I do that most of the time
But nowadays all we have are the constant top off folks jamming all the stations up.. it sucks

I've not seen that behavior, but then again, when we're not traveling, I can go many weeks before filling up.

 

[Zee09]

I've not seen that behavior, but then again, when we're not traveling, I can go many weeks before filling up.

Every station is that way here which is rural. I never had to wait for pumps and people are trying to skirt the increases like the 20 cent raise yesterday. They top off almost daily

 

[CleanSump]

Just used the fast Diesel pump and did it at medium because otherwise it clicks off all the time.
Lots of people doing the $20 of gas thing here. At least we have gas and aren't in lines.
Exxon Diesel was 30 cents cheaper than the Royal Farms and No-Name across the street. The other major names are 40 to 45 cents higher! I don't know how Exxon/Mobil is doing this. Maybe being nice and not raising just because they can or more likely doing the K-Mart lower markup to entice higher volume vice the Niemen Marcus high markup to make up for low volume for snob appeal.