I have been giving much thought to the driving range of our rig. One issue is fuel temperature when it comes out of the hose. Contrary to what most people think, fuel temperature is NOT compensated for (@ least in California). It is delivered temperature compensated but at the pump its at what ever the ground/meter temperature is. Most dealers get several hundred (extra) gallons that is pure profit on every tanker load due to this temperature spread. A recent offer by the main maker of Ca. fuel pumps to furnish free in new pumps, temperature compensation valves, was quietly shelved recently. I suspect that fuel temperature (density) is a major culprit (in milage variation) as it can vary by almost 20%. With fuel prices @ $4, a warm fuel temperature can cost you as much as 80 cents a gallon. Oddly enough, temperature compensation is by law in Canada. Does anyone have any information on this in other states?
While I have found that the DIC (combo fuel/milage indicator) is generally accurate, I also have seemed to note that the fuel temperature when pumped, and how much I coax all the foam out of the tank can make a large difference in both the calculated by hand and the DIC readings, sometimes more than several MPG. This also seems to affect the gallons used figures which would logically follow. While this may seem academic to some, we are out west where the fuel points, and the reasonable fuel costs, are often very far apart. We sometimes push our maximum range with the 56 gallons we carry and 1 or 2 mpg, and a warm fuel load can drastically reduce how far you are going to get. We have noted almost a 100 mile difference in supposedly "full" tanks. We drive fairly consistently and while the terrain varies and accounts for some of the variation, we suspect that temperature and topping off also affect fuel range.
Bill and Carole
2K8 Chevy LTZ Turbo Diesel
Transfer Flow Fuel
2K7 Komfort 241fs
Lots of minor mods
USAF Ret - Nam thru Desert Storm
According to an article in "Land Line" magazine hot fuel from Flying-J has been questioned for some time. Some drivers actually take the temperature of the fuel and avoid it if it's too hot.
So tell me how hot is the fuel that comes from the ground. I would say it is 55 deg. no matter how hot or cold it is. Remember that fuel is stored underground and though you may have a little in the hose to deal with, beyond that it is all the same. there is no way you are losing 80 cents per gallon or even .08 per gallon. Anothe conspiricy theory about how the oil companies are doing us in. It makes for a good read and a chuckle every couple of days.
93 Airstream 35' Dp
5.9 230 uprated to 300 HP
Allison MD 3060
Dutchess and Shadow (fur Bearing Children)
The only thing I have had any experience with is fueling my airplane.
If I filled the wing tanks and let the plane sit out in the sun the gas would expand and some would run out the vents.
I never tried to capture this gas I just let it hit the ground and kill the grass.
I doubt very much gas was lost due to expansion.
And I never ran out while flying.
when the fuel comes from the distributors to the stations it comes from above ground tank farms then put in the ground.most of the fuel oil distributors that deliver home heating fuel comes from above ground tanks.how much that makes a differance i dont know,try fueling up in the early morning while your traveling see if that makes a differance it should be cooler then.
1985 Class A Holiday Rambler Imperial 33 +1979 Class C Holiday Rambler Statesman 1000 = 24 ft
tom_kat wrote: when the fuel comes from the distributors to the stations it comes from above ground tank farms then put in the ground.most of the fuel oil distributors that deliver home heating fuel comes from above ground tanks.how much that makes a differance i dont know,try fueling up in the early morning while your traveling see if that makes a differance it should be cooler then.
Please explain how fuel can be cooler in the morning when it is stored in underground tanks, that has a constant temp. of 55 degrees. I agree that fuel delivered from tankers may have some additional thinking about the temp. But how can it effect fuel stored under ground.? That is what we the consumers are paying for.
While temperature certainly does make a difference the only thing a consumer can do is try to get your congressman to pass legislation requiring temperature compensating metering. Time of day makes no difference unless you only buy 1/2 gallon at a time. The pump and hoses contain a minimal amount of fuel that can warm during the time it sits. The fuel usually does not sit long enough in the underground tanks to drastically change the temperature. In conclusion you are buying fuel at whatever temperature it was delivered. The refinery/delivery service uses temperature compensating metering, USA pumps do not. Canada pumps do. In the summer we get cheated in the USA.
Tim
"Okay, I admit it, the only thing I'm really good at is being me."
Lets look. 300 gallons in a 5000 gallon load equals .06% That certainly does equate to a 20% expansion factor. If you fill your 50 gallon tank cool and let it sit and thermal expand, does 10 gallons of fuel run from the vent? or 5 gallons? Not gonna happen. Yes there is thermal expansion but no where near the numbers you are talking about.
Bill
2000 Hitchhiker II Rio Grande
2000 Dodge 3500 dually Cummins 5 speed Edge EZ and guages
This whole idea of "Hot Fuel" boggles my mind. You have a 10,000 to 20,000 underground fiberglass or maybe steel tank or tanks filled with a combustable product. Just how do you propose to heat this to make the fuel hot. And even if you did heat the tanks, would you be able to recoop the cost of heating the fuel? I don't think so. It takes a lot of energy to heat 10 to 20 thousands gallons of liquid, and a lot of insulation to maintain that heat. I have seen many tanks being installed at stations. I have never seen any type of heating devise being installed with the tanks. Maybe one could use a instant use type heater, but any type of electrical components require special considerations when installed in this type of system. I really doubt anyone is heating fuel.
I have hauled fuel during the winter months when it was hot because it had just been refined. 80 and 90 degrees was not unusual. But fuel is usually sold as Net Gallons or Gross Gallons. Gross gallons are what you pay at the station with the product going thru the meter and nothing else take in consideration. Net gallons is gross gallons which are adjusted by formula using temperature. You can see this from the following chart from the State of Texas Comptrollers Office:
"GALLONS ON GROSS OR NET BASIS
The fuels industry for many decades has generally sold, or accounted for fuel corrected to a temperature of 60 degrees Fahrenheit, commonly referred to as a net basis. Fuel at an actual volumetric quantity is referred to as gross gallons. The net gallons of fuel above 60 degrees will be less than the gross amount and the net gallons of fuel below 60 degrees will be greater than the gross amount.
The following table indicates the approximate difference between gross and net gallons of gasoline at a gravity of 62. There are several different tables that result in slightly different figures.
As you see, the chart takes the hot or cold fuel and adjusts the gallons to equalize between the above ground temperature and the 60 degree underground tank temperature.
I hauled petroleum products for over 20 years and I consider the Flying J Hot Fuel issue to be a figment of the over active mind of some truck driver who spent to much time playing Pac Man. In other words - Bunkum!
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