Mileage
Senior Member
Joined: Dec 2013
Posts: 14,975
Likes: 6,035
From: SE Michigan
I don't have the foggiest notion of what the "but you" statement means. If you're commenting on me personally then I take exception and place any value of your input lower. If my questions bother you then just don't read them when you see my name.
I like to know how things work. It would be pretty easy for the computer of the truck to observe the odometer mileage and the position of the gas gauge. That could give a mpg and a range indication. It would have to be a sophisticated gas gauge sensor to be as accurate as it is. I think all of the F-150s have some sort of instantaneous mpg indicator. Mine is a graph. It shows a distinct change when I move the gas pedal and also when I go over a hill. So there has to be a third factor in the calculations.
I still don't understand why not just read the odometer and a good flow indicator and be done with it, so far as mpg goes. Maybe they do and use the same flow indicator for every truck and do a poor job of calibrating it.
I like to know how things work. It would be pretty easy for the computer of the truck to observe the odometer mileage and the position of the gas gauge. That could give a mpg and a range indication. It would have to be a sophisticated gas gauge sensor to be as accurate as it is. I think all of the F-150s have some sort of instantaneous mpg indicator. Mine is a graph. It shows a distinct change when I move the gas pedal and also when I go over a hill. So there has to be a third factor in the calculations.
I still don't understand why not just read the odometer and a good flow indicator and be done with it, so far as mpg goes. Maybe they do and use the same flow indicator for every truck and do a poor job of calibrating it.
Old Fart
Joined: Aug 2013
Posts: 3,001
Likes: 1,264
From: Clinton TN
As I found out years ago from a state official that was checking a gas pump for a new set of official stickers from the department of weights and measurements, gas is measured coming out of the ground at a pretty constant temperature is basically going to be pretty close all the time, but like most liquids the measurement is off if there are changes in temperature. So something that reads correct at 65 degrees might not be the same at 90 degrees. My hundred gallon Fuel transfer tank in the say not to fill it to the top, it will expand when it gets warm. The flow rate will also be different at different temps and if your Truck had fuel that was going to be the same temp all the time they could set the fuel use and mile to empty a lot closer but alas we are stuck with different temps so it can be close. You could be like the old cars and trucks and just have a fuel gauge and you figure out the mileage and when to stop for gas all on your own.
Thread Starter
Senior Member
Joined: May 2019
Posts: 169
Likes: 16
From: Sulphur, Oklahoma
As I found out years ago from a state official that was checking a gas pump for a new set of official stickers from the department of weights and measurements, gas is measured coming out of the ground at a pretty constant temperature is basically going to be pretty close all the time, but like most liquids the measurement is off if there are changes in temperature. So something that reads correct at 65 degrees might not be the same at 90 degrees. My hundred gallon Fuel transfer tank in the say not to fill it to the top, it will expand when it gets warm. The flow rate will also be different at different temps and if your Truck had fuel that was going to be the same temp all the time they could set the fuel use and mile to empty a lot closer but alas we are stuck with different temps so it can be close. You could be like the old cars and trucks and just have a fuel gauge and you figure out the mileage and when to stop for gas all on your own.
Years ago some gasoline stations had above ground tanks. Those gasoline tanks are all underground now and the temperature just doesn't change more than a few degrees. Certainly not enough to expand the volume of the gasoline stored there. Your hundred-gallon fuel transfer tank is another story. It will change with the ambient temperature. The flow rate might chance when pumped from it. The gasoline pumped from an underground tank at a commercial filling station is metered correctly at all temperatures.
Even back in the day the idea that you should buy gasoline in the morning because it was cooler and you'd get more gasoline was an old wife's tale. Any expansion due to the above-ground tanks was insufficient to affect the gas mileage more than a few percent. Certainly in the low single digits. Your state official was full of malarky.
Thread Starter
Senior Member
Joined: May 2019
Posts: 169
Likes: 16
From: Sulphur, Oklahoma
At 60 degrees gasoline occupies 231 cubic inches. At 90 degrees it occupies 235.8 cubic inches. So the change is 4.8 cubic inches. Or 2 percent. The gasoline in an underground tank at a filling station is not going to change more than 5-10 degrees from delivery to dispensing. So basically no change in the volume of the gasoline pumped at the station.
Old Fart
Joined: Aug 2013
Posts: 3,001
Likes: 1,264
From: Clinton TN
Years ago some gasoline stations had above ground tanks. Those gasoline tanks are all underground now and the temperature just doesn't change more than a few degrees. Certainly not enough to expand the volume of the gasoline stored there. Your hundred-gallon fuel transfer tank is another story. It will change with the ambient temperature. The flow rate might chance when pumped from it. The gasoline pumped from an underground tank at a commercial filling station is metered correctly at all temperatures.
Even back in the day the idea that you should buy gasoline in the morning because it was cooler and you'd get more gasoline was an old wife's tale. Any expansion due to the above-ground tanks was insufficient to affect the gas mileage more than a few percent. Certainly in the low single digits. Your state official was full of malarky.
Even back in the day the idea that you should buy gasoline in the morning because it was cooler and you'd get more gasoline was an old wife's tale. Any expansion due to the above-ground tanks was insufficient to affect the gas mileage more than a few percent. Certainly in the low single digits. Your state official was full of malarky.
Thread Starter
Senior Member
Joined: May 2019
Posts: 169
Likes: 16
From: Sulphur, Oklahoma
And I just posted the gasoline in a vehicle tank also expands very little. The difference between nighttime and daytime temperatures is seldom more than 30 degrees anywhere in the US. So a maximum expansion of 2%. Insignificant when calculating mpg and range.
Old Fart
Joined: Aug 2013
Posts: 3,001
Likes: 1,264
From: Clinton TN
But the difference between summer and winter in some areas is over 100 degrees and you take a car getting sent to Needles California while the next in line goes to Prudhoe Bay Alaska you could have a 160 degree variation, so auto manufactures make the system to work everywhere and since they cannot make everyone happy they don't try to make anyone happy.
My 2002 Explorer was a vehicle that when you figured out MPG was within less than a tenth of a mile off and when it hit zero miles to Empty it quit running, so I do know Ford got it right once.
My 2002 Explorer was a vehicle that when you figured out MPG was within less than a tenth of a mile off and when it hit zero miles to Empty it quit running, so I do know Ford got it right once.
Thread Starter
Senior Member
Joined: May 2019
Posts: 169
Likes: 16
From: Sulphur, Oklahoma
But the difference between summer and winter in some areas is over 100 degrees and you take a car getting sent to Needles California while the next in line goes to Prudhoe Bay Alaska you could have a 160 degree variation, so auto manufactures make the system to work everywhere and since they cannot make everyone happy they don't try to make anyone happy.
My 2002 Explorer was a vehicle that when you figured out MPG was within less than a tenth of a mile off and when it hit zero miles to Empty it quit running, so I do know Ford got it right once.
My 2002 Explorer was a vehicle that when you figured out MPG was within less than a tenth of a mile off and when it hit zero miles to Empty it quit running, so I do know Ford got it right once.
It's not the difference in temperature that causes the manual calculations and the computer calculations to be different. It's how the computer does the calculation, whatever that is.
Old Fart
Joined: Aug 2013
Posts: 3,001
Likes: 1,264
From: Clinton TN
Thread Starter
Senior Member
Joined: May 2019
Posts: 169
Likes: 16
From: Sulphur, Oklahoma
That is what I am saying, the system is setup to measure all temperature ranges and get it somewhat close, like I said it has to be able to take a reading somewhat close in Needles and Prudhoe Bay as well as everywhere in between. Auto manufactures are not going to put extra sensors in to make the system more accurate sense it would be one more thing to break and need repair if it was not accurate. Can you imagine an auto manufacturer getting sued because the system said 2 miles to empty and they ran out of gas on the interstate and someone got rear ended and died. The way it is now is a CYA move on the auto manufactures part since it is not correct.