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Could I place a Multimeter on the wires leading to the fuel guage and get an accurate fuel level. I wonder if getting resistance or voltage readings can tell me the reference points when I'm calculating MPG. I sometimes fillup the tank, reset my Odometer and drive 200 miles, then fillup and again noting the number of gallons at the pump. The question is how do I know, if the level of fuel in the tank is at the same level each time I fill up ?
I am a little confused here! If you fill it up then the only reason to note gallons is to check MPG not level. If you know your average MPG and approx. size of tank then you know about how far you can go. Your gas gauge does not really tell you anything that you can't figure out on your own.
Now back to your question. A mutlimeter might be able to tell you something if you are sure it is your gauge that is bad. If it is your sending unit in the tank then it won't help. I am presuming you want to use the multimeter as a fuel gauge?
Okay who is more confused now? You or me?
Gary
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Don't worry about what other people think....as most of them don't!
I doubt the reading from a multimeter can give you a better MPG calculation than the fuel gauge..
temperature and tank pressure can effect the reading. Also you need the coefficient to convert the voltage to the volume of fuel. In addition, the mechanism which detect the fuel level may or may not give you a linear reading.
you can do it, but there are a lot of uncertainties and error.
The multimeter will not be used to check level of fuel in tank. 1/2 tank shows the guage needle at 1/2 mark and the multimeter I think this should give me a reading .
Full tank should give me a different multimeter reading.
The multimeter will not be used to check level of fuel in tank. 1/2 tank shows the guage needle at 1/2 mark and the multimeter I think this should give me a reading .
Full tank should give me a different multimeter reading.
there is a real simple way to do this drive you car untill you have the gas light on, then drive 20 miles and fill up, at this point note what you put in and reset trip. drive your car untill the next fill up. fill up again and note. All you really need to know is the size of your tank, lets say it's 16 if you run the car till the light is on and fill up you should have to put in around 14 or so gal. This would tell you that your tank is getting filled to about 98% if not 100%. which would allow you to calculate your milage within 2 mpg+/-.
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The camry was designed as a car for the masses it is not fast or flashy and therefore I will not make it that way...................................damn I need a fast car.
I guess Im asking how to convert my Analog fuel guage into a Digital one. Im an accurate kind of person.
Wow. if that is what you are doing. I think it will be quite difficult or impossible. There is no way the car will know how many gallons/liters left in your tank, even if you change your gauge to digital. So you mean you want a digital reading to say, for example, 14.32 gallons left in tank.
Cars that have MPG reading gauges does it by knowing how many gallons of gas it uses and miles it has travelled. It doesnt car how many gallons are in the tank itself.
For example, if you have a car with MPG readings, it uses the mileage travelled and the gas used in this trip to calculate your MPG.
In short, cars can calculate how many miles you have travelled (obviously) and how much gas you have used for that trip. Having these two numbers, it can calculate your miles per gallon.
Hope this makes sense. I don't think there is car out there that knows exactly how many gallons you have left in your tank.. that level of accurancy is difficult measure for many reasons. Gas tank uses a pressure sensor to give a rough idea how much gas is left.
Could I place a Multimeter on the wires leading to the fuel guage and get an accurate fuel level. I wonder if getting resistance or voltage readings can tell me the reference points when I'm calculating MPG. I sometimes fillup the tank, reset my Odometer and drive 200 miles, then fillup and again noting the number of gallons at the pump. The question is how do I know, if the level of fuel in the tank is at the same level each time I fill up ?
Sorry to reply to an old post, but I felt sorry for q.
What he(?) wanted to know (I think) was how to determine how much gas he actually used during that 200 miles of driving, so he could calculate his fuel mileage. If he was able to, using a VOM, determine how full his gas tank was right after the first fill-up and before the 200 miles, AND, after the 200 miles, was able to determine how full his gas tank was after the second fill-up, he could accurately determine fuel mileage.
I'm not sure about the fuel quantity measurement system's ability to provide that data. What I DO know is that one should determine fuel mileage after at least three successive fill-ups. Then, any errors introduced by gas pump shut-off variances should be trivialized.
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Digger1
"If you don't understand the technology you depend upon, you will someday be a victim of that technology."
I just divide miles by gallons, thats good enough for me...but BTW my owner manual says my 2002 V6 has a gas tank of 18.5 gallons. If that helps some one.
Sorry to reply to an old post, but I felt sorry for q.
What he(?) wanted to know (I think) was how to determine how much gas he actually used during that 200 miles of driving, so he could calculate his fuel mileage. If he was able to, using a VOM, determine how full his gas tank was right after the first fill-up and before the 200 miles, AND, after the 200 miles, was able to determine how full his gas tank was after the second fill-up, he could accurately determine fuel mileage.
I'm not sure about the fuel quantity measurement system's ability to provide that data. What I DO know is that one should determine fuel mileage after at least three successive fill-ups. Then, any errors introduced by gas pump shut-off variances should be trivialized.
Ok, you guys are making this MPG calculation way more complicated than need be. Besides why would one need such a level of accuracy. The process to calculate MPG is very simple:
1. FILL up TANK
2. Reset odometer
3. Drive a few hundred miles/kilometers to get a decent average
4. Fill up tank again, note the gallons.
5. You have gallons used and miles travelled.
Repeat the above steps again for the about 5 to 6 times and that would give you a good average. Done.
Well jet aircraft use a capacitance resistance type of system for measuring fuel quanity and its measured in picofarads which is pretty small amount if I recall. And you will need a tank compensator to measure they density of fuel constantly as fuel density will change day to day week to week. So I don't think you will find a standard multi-meter that will measure that low nor be able to calculate the density of fuel constantly.
Maybe upgrading to a car with a trip calculator would be cheaper! lol
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Fuel Guage level
If you fill it up then the only reason to note gallons is to check MPG not level. If you know your average MPG and approx. size of tank then you know about how far you can go. Your gas gauge does not really tell you anything that you can't figure out on your own.
A mutlimeter might be able to tell you something if you are sure it is your gauge that is bad. If it is your sending unit in the tank then it won't help. I am presuming you want to use the multimeter as a fuel gauge?
Linear Mode
