How does the lie-o-meter compute?
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Freshman User
Joined: Aug 2005
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How does the lie-o-meter compute?
Odd question...how does the lie-o-meter (that's what i have commonly heard it referred to as) compute the mpg? Is it a direct relation to wheel travel?
I ask this becuase my mileage is showing low, and i'm trying to figure out if it is due to the reduction in power with the tire install, or if it is due to the computer being thrown off by tire size. Becuase i guess my mph will show lower now too, which i guess means my mpg will show lower. I'm just not sure if that how it computes it or not.
I am hoping so. Hate to think that i have really dropped 2 mpg with the install of my new tires. I can lived with an innacurate computer.
Is ther a way to fix it if this is the problem. Ilove to monitor the mpg, but not as fun if it's not accurate.
thanks!
I ask this becuase my mileage is showing low, and i'm trying to figure out if it is due to the reduction in power with the tire install, or if it is due to the computer being thrown off by tire size. Becuase i guess my mph will show lower now too, which i guess means my mpg will show lower. I'm just not sure if that how it computes it or not.
I am hoping so. Hate to think that i have really dropped 2 mpg with the install of my new tires. I can lived with an innacurate computer.
Is ther a way to fix it if this is the problem. Ilove to monitor the mpg, but not as fun if it's not accurate.
thanks!
Posting Guru
Joined: Jul 2003
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It uses the reading from the same sensor that the odometer and speedometer use. So if you changed tires sizes without telling the computer about it, your trip computer won't be accurate. The computer can bbe reprogrammed with the new tires size so that everything reads correctly. Ask your dealer.
Larger tires can reduce fuel economy.
Larger tires can reduce fuel economy.
Senior User
Joined: Jan 2005
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From: Monterey Park, California
I thought of this too, and came to this conclusion.
It must use throttle position, speed and rpms to figure the mpg. And the miles to empty is figured by the fuel gauge reading and existing mpg calculated.
When you put in a tuner or chip, your throttle position is less, so you get more mpg.
It must use throttle position, speed and rpms to figure the mpg. And the miles to empty is figured by the fuel gauge reading and existing mpg calculated.
When you put in a tuner or chip, your throttle position is less, so you get more mpg.
Senior User
Joined: Jan 2005
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From: Monterey Park, California
That's why it's called the lie-o-meter.
When you put in the tuner and your throttle position is less, the engine doesn't get less fuel at that throttle position. It actually gets more as if you were pressing the throttle more. The computer only knows the throttle position, and NOT the amount of fuel actually consumed. Thus you get the false readings. The computer is not lieing but just telling us what it sees. The computer is being fooled. It's not a fool just tricked, but whoever believes that they are getting more mph after a tuner install is. Fool-o-meter is more like it!
When you put in the tuner and your throttle position is less, the engine doesn't get less fuel at that throttle position. It actually gets more as if you were pressing the throttle more. The computer only knows the throttle position, and NOT the amount of fuel actually consumed. Thus you get the false readings. The computer is not lieing but just telling us what it sees. The computer is being fooled. It's not a fool just tricked, but whoever believes that they are getting more mph after a tuner install is. Fool-o-meter is more like it!
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Posting Guru
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Originally Posted by Hello
It must use throttle position, speed and rpms to figure the mpg.
Originally Posted by Hello
And the miles to empty is figured by the fuel gauge reading and existing mpg calculated.
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Joined: Jan 2002
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From: La La Land
Casey,
The flow rate must be based on what AD's will flow (on average) with the HPOP regulated to factory specs. Since the flow rate of the injectors will change with the HPOP pressure, can we then also fool the calculation with something like a 10K mod?
Pop
The flow rate must be based on what AD's will flow (on average) with the HPOP regulated to factory specs. Since the flow rate of the injectors will change with the HPOP pressure, can we then also fool the calculation with something like a 10K mod?
Pop
Senior User
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From: Monterey Park, California
Originally Posted by Casey
Nope. It uses vehicle speed and time to calculate distance, and uses the injector pulsewidth and the flow rate of the injectors to calculate how much fuel is used. Throttle position and RPM don't make a difference, other than both of those will change to pulsewidth of the injectors.
Posting Guru
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Originally Posted by Hello
If this is true, then why doesn't the lie-o-meter show a higher mpg after a chip of tuner install.
From many reports I've heard the computer DOES show a higher MPG after installing a chip or tuner.
Posting Guru
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Originally Posted by SpringerPop
The flow rate must be based on what AD's will flow (on average) with the HPOP regulated to factory specs. Since the flow rate of the injectors will change with the HPOP pressure, can we then also fool the calculation with something like a 10K mod?
Senior User
Joined: Jan 2005
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From: Monterey Park, California
Originally Posted by Casey
Because a chip or tuner fools the computer into thinking the flow rate is different that it really is. That's how they make more power, they inject more fuel. The computer doesn't know this, it thinks the flow rate is still stock.
From many reports I've heard the computer DOES show a higher MPG after installing a chip or tuner.
From many reports I've heard the computer DOES show a higher MPG after installing a chip or tuner.
My mpg after the Predator 100hp tune is hugh. I could get up to 25mpg on the lie-o-meter, and I actually hand calculate it to 15mpg.
Posting Guru
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It doesn't use throttle position in the calculation. It calculates the amount of fuel that is being injected. It's that easy.
The engine computer calculates how much fuel, partially based on throttle position. With a tuner or other power enhancing mod you get more fuel than the computer knows about. The engine computer tells the trip computer about the fuel it knows was used, but in reality more fuel was used. Now the trip computer calculates the wrong mileage.
The display will go higher because with a tuner you only get more fuel when you stomp on it. With or without a tuner it takes exactly the same amount of fuel to cruise down the highway at 70 MPH. The difference is that you press the pedal down a bit less with the tuner so that the computer thinks you are using less fuel than you really are.
And I'm not guessing, I know how this works.
The engine computer calculates how much fuel, partially based on throttle position. With a tuner or other power enhancing mod you get more fuel than the computer knows about. The engine computer tells the trip computer about the fuel it knows was used, but in reality more fuel was used. Now the trip computer calculates the wrong mileage.
The display will go higher because with a tuner you only get more fuel when you stomp on it. With or without a tuner it takes exactly the same amount of fuel to cruise down the highway at 70 MPH. The difference is that you press the pedal down a bit less with the tuner so that the computer thinks you are using less fuel than you really are.
And I'm not guessing, I know how this works.
Tuned
Joined: Dec 2001
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From: Saskatoon sk
I can believe it calculates the mpg from the amount of fuel injected. As I have a 100 gallon tank auxilary tank with a remote controlled transfer pump that moves the fuel into the fill pipe. I can drive all day without shutting down and usually fill when gauge gets to 1/4 tank. I can fill a few times in a day and the fuel gauge gets confused. but still remembers miles to empty.