Tips for fueling up

[Wild one]

TIPS ON PUMPING GAS
I don't know what you guys are paying for gasoline.... My line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every gallon:
Here at the Kinder Morgan Pipeline where I work in San Jose , CA we deliver about 4 million gallons in a 24-hour period thru the pipeline.. One day is diesel the next day is jet fuel, and gasoline, regular and premium grades. We have 34-storage tanks here with a total capacity of 16,800,000 gallons.
Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role.
A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.
When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.
One of the most important tips is to fill up when your gas tank is HALF FULL. The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.
Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

 

[Mb7640]

Great advice the only thing that I did know is not getting gas when the tanker is there. I will be using the low setting for now on. Here in the summer its still 90 degrees out in the morning. I normally get gas in the morning on the way to work anyways. Thanks again

 

[GTyankee]

Another reason to not fill your fuel tank while a tanker is pumping fuel into the tanks at a Service Station.....

Unfortunately, the truck drivers screw up sometimes

The wrong Product is pumped into the wrong Tank.
If you are lucky, the truck driver pumps Premium gas into the Regular Tank, that is what a truck driver friend of mine did, on his last day of hauling fuel. He went back to hauling Dry Goods.

What if his mistake was a diesel/gasoline mistake
They would likely discover the mistake as soon as he called in, before leaving for the next station.

There would be pandamonium & crying customers

 

[Tray Burge]

Great tips, makes terribly unarguably common sense too. I'll change my fueling habits.

 

[bm02tj]

Yes fill in morning but I will use high as my time is more valuable than the 5 or 10 cents I might loose

 

[mikeru]

I was already doing everything in that list except for filling on the lowest setting. I'll change that from now on too. Thanks for posting that, Rick!

 

[Wild one]

I was already doing everything in that list except for filling on the lowest setting. I'll change that from now on too. Thanks for posting that, Rick!

My Dad taught me to always put the trigger setting on the lowest setting,way back when i was a kid fueling up tractors,but i think it was to miniumize spillage,back then,lol.

 

[Dodge 1500 4X4]

Wow, Thanks Rick 3 things I didn't know about the morning cooler temp, using the lowest setting when filling, and not to fuel up when the tanker is there.

 

[Docwagon1776]

View attachment 545782 Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon.

Whoever you got that from doesn't understand thermal mass and ground temperature. Unless that tank is less than a foot from the surface, daily temperature variations are completely insignificant. Ground temperature is pretty constant once you get below the top 5-6 inches and takes *months* to change from ambient air temperature at 10 feet or so. You'd need a roughly 15 degree (F, I don't speak C) swing to change the volume of gasoline by 1%. The temperature the gas was dispensed at and how much time it's had to equalize with the surrounding ground is going to be the biggest driver of temperature, not time of day.

I suspect the evaporation thing is not really that influenced by how much air space you have, either. Maybe a touch more evaporation due to lower volume of liquid heating up easier, but surface area is going to be pretty constant and those are the two things that drive evaporation rates (temp and surface area). I suspect the difference in filling up at 1/2 vs 3/4 or 7/8 isn't going to overcome the extra start and idle from filling up more often. I don't remember the calculations any longer and they assumed an open container (the goal was for booby trap style demolitions, you wanted something to evaporate enough to fill an area between the Lower Explosive Limit and Upper Explosive Limit in a certain time), but do remember the overall theory.

Don't know enough about gas nozzles to comment there, it makes sense as a possibility as more turbulent flow will atomize more liquid, but again probably teaspoons a year. Maybe tablespoons.

 

[mtofell]

OP it's clear you know a lot about this and I don't so everyone take this with a grain of salt.... but, what are we talking here? Morning vs. afternoon fill? I feel like I could follow this advice my whole life and save $5.... maybe. Underground temps are VERY consistent with basements, water storage and other things I do know about and I just don't see how 6 hours makes any difference.

Not filling up when a truck's filling the station tanks? All stations have filters, alarms and all kinds of other things built in. This sounds like advice from the 1980s.... maybe I'm just rich and reckless but I just fill up when I need fuel and have never had a problem.... nor heard of anyone else having a problem.

 

[Wild one]

Whoever you got that from doesn't understand thermal mass and ground temperature. Unless that tank is less than a foot from the surface, daily temperature variations are completely insignificant. Ground temperature is pretty constant once you get below the top 5-6 inches and takes *months* to change from ambient air temperature at 10 feet or so. You'd need a roughly 15 degree (F, I don't speak C) swing to change the volume of gasoline by 1%. The temperature the gas was dispensed at and how much time it's had to equalize with the surrounding ground is going to be the biggest driver of temperature, not time of day.

I suspect the evaporation thing is not really that influenced by how much air space you have, either. Maybe a touch more evaporation due to lower volume of liquid heating up easier, but surface area is going to be pretty constant and those are the two things that drive evaporation rates (temp and surface area). I suspect the difference in filling up at 1/2 vs 3/4 or 7/8 isn't going to overcome the extra start and idle from filling up more often. I don't remember the calculations any longer and they assumed an open container (the goal was for booby trap style demolitions, you wanted something to evaporate enough to fill an area between the Lower Explosive Limit and Upper Explosive Limit in a certain time), but do remember the overall theory.

Don't know enough about gas nozzles to comment there, it makes sense as a possibility as more turbulent flow will atomize more liquid, but again probably teaspoons a year. Maybe tablespoons.

Admittedly on a day to day basis,there's not much saving,but practiced over a 40 year period,there's probably a noticable saving in fuel costs

 

[Wild one]

OP it's clear you know a lot about this and I don't so everyone take this with a grain of salt.... but, what are we talking here? Morning vs. afternoon fill? I feel like I could follow this advice my whole life and save $5.... maybe. Underground temps are VERY consistent with basements, water storage and other things I do know about and I just don't see how 6 hours makes any difference.

Not filling up when a truck's filling the station tanks? All stations have filters, alarms and all kinds of other things built in. This sounds like advice from the 1980s.... maybe I'm just rich and reckless but I just fill up when I need fuel and have never had a problem.... nor heard of anyone else having a problem.

A filter is only as good as it's maintence,and whens the last time you've seen a servicable filter on the gas pump being replaced. I know if the tanker is there filling the tanks,i try to wait at least 24 hours for the majority of contaments to settle out of suspension. When you figure the majority of vehicles on the road now a days don't employ a replacable fuel filter anymore,at most they might have a coarse sock on the bottom of the fuel pump,why risk the chance of pumping your tank full of dirty fuel

 

[BossHogg]

The volume coefficient of the expansion of gasoline is 0.00095 per degree Celsius. There are several volume calculators online but to make this simple, a 30-degree change from 45 to 75 degrees F on 12 gallons of gasoline equates to a volume increase of 0.352 gallons, fairly significant especially for those doing hand calculations to determine MPG, in this example, the MPG could change by 0.427 MPG. Calculated by using a vehicle with an average MPG of 18 MPG driven 180 miles.

The expansion and contraction of fuel is the reason why aircraft measure fuel by weight and not by volume (gallons), engines do not consume volume, they consume weight. Granted, our vehicles will not see the temperature deltas an aircraft sees but even at temperature swings of 30 degrees, the volume changes are noticeable.

 

[Sherman Bird]

TIPS ON PUMPING GAS
I don't know what you guys are paying for gasoline.... My line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every gallon:
Here at the Kinder Morgan Pipeline where I work in San Jose , CA we deliver about 4 million gallons in a 24-hour period thru the pipeline.. One day is diesel the next day is jet fuel, and gasoline, regular and premium grades. We have 34-storage tanks here with a total capacity of 16,800,000 gallons.
View attachment 545782 Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role.
A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.
View attachment 545783 When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.
View attachment 545784 One of the most important tips is to fill up when your gas tank is HALF FULL. The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.
View attachment 545785 Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

Similarly, when I handle A/C refrigerant on vehicles, e.g. I replace an engine in a car where I must discharge the A/C refrigerant during the mechanical work, if the ambient temperature is, say, 70 degrees, and I refill the system by weight, invariably, I have to revisit the system and add a small amount when our 100 degree days visit us.
Hydrocabons change properties due to temperature, and humidity.
I've always done as you advise, but I am in the business. Great post!

 

[Docwagon1776]

Admittedly on a day to day basis,there's not much saving,but practiced over a 40 year period,there's probably a noticable saving in fuel costs

What are you going to do if you're at 1/2 a tank and it's not one of the "cool times" to get gas?

 

[turkeybird56]

What are you going to do if you're at 1/2 a tank and it's not one of the "cool times" to get gas?

Ahhhhhhhhhhhhhhhhhhh, gas up??? lol...

ADDED: My wife ran a station in town here for years and I knew exactly which stations did MX on tanks and pumps and which ones did not, as there is only 1 company in this area that comes out rural. SO I always knew which ones to avoid. Knew to neva get fuel after and/or doing tanker drop. I ran a Hess Station for a few years. I also got the bejesus scared outta me by a driver: He was on top of truck, not dropped fuel yet and said: Watch this and he dropped a lit match into tank, no issue,. BUT he did caution U might not wanna do that trick once the tank starts emptying and/or on an empty tank. That guy was such a dude, lol.

CAVEAT: NE body remember the early 70's and the gas lines. In NJ, we had the odd/even days and the Flags that were put out: Green get all the gas U want, Yellow limited, Red no gas.

 

[Scottly]

A filter is only as good as it's maintence,and whens the last time you've seen a servicable filter on the gas pump being replaced.

Food for thought...If a filter clogs, it won't flow fuel. It will flow fuel if it's damaged, but it won't stop filtering if it clogs...It's just stop flowing.

 

[photoguynorth]

I'm not sure if this is the same outside of Canada, but most if not all pumps here are temperature compensating, so the temperature does not impact the actual amount of fuel you get (and they have a sticker indicating that volume is corrected to some temperature). On the other hand, if you fill right up on a hot day, it can expand in your tank and some will be forced out through the vent filter. Unless conditions are extreme though, and you completely top off your tank, I very much doubt a meaningful amount would ever be lost. Edit: I worded that poorly, technically the temperature could affect how much fuel you actually get, but the quantity and cost on the pump will be adjusted to compensate for any volume changes caused by temperature.

 

[photoguynorth]

The volume coefficient of the expansion of gasoline is 0.00095 per degree Celsius. There are several volume calculators online but to make this simple, a 30-degree change from 45 to 75 degrees F on 12 gallons of gasoline equates to a volume increase of 0.352 gallons, fairly significant especially for those doing hand calculations to determine MPG, in this example, the MPG could change by 0.427 MPG. Calculated by using a vehicle with an average MPG of 18 MPG driven 180 miles.

The expansion and contraction of fuel is the reason why aircraft measure fuel by weight and not by volume (gallons), engines do not consume volume, they consume weight. Granted, our vehicles will not see the temperature deltas an aircraft sees but even at temperature swings of 30 degrees, the volume changes are noticeable.

You switched from Celsius to Fahrenheit , the actual change in your example would be closer to 0.16 gallons. Driving at 75 degrees Celsius, mpg is the least of your worries

 

[Yardbird]

Gas stations have underground storage tanks (USTs) almost 100% of the time. Way back, there were places with above ground tanks, but I haven't seen one in years.

The tank farms, where the trucks are loaded, are above ground. That's the reason for temperature compensation at the loading rack.

If a pump is pumping slow, it probably has a clogged up filter.

I drove a gas tanker for a while, and also owned a gas station.

I changed my filters religiously, and also checked my dispensers regularly with a certified metered can that would show if 5 gallons was actually pumped when the pump said 5 gallons.

I also made a roll around pump from an old gas pump. I used this to pump out the very bottoms of my underground storage tanks. This ensured a clean tank and gas.

I had competition, and did all I could to insure the customers had a good experience with my gas, Including keeping the dispensers clean and freshly painted.

Most of the water and sludge in an underground tank will come from the truck delivering gas, which they get from the tank farm.

If a pipeline delivery doesn't settle in the large tank farm tanks long enough, the contamination from the pipeline will move to the truck and to the end user.

I've had it happen to me several times. I've opened the top hatches and seen almost black diesel fuel loaded onto my truck. This was years ago, so the process may have improved since then, hopefully.