How Does JK Calculate gas mileage?
Thread Starter
JK Jedi
Joined: Apr 2011
Posts: 4,482
Likes: 2
From: Neenah, Wisconsin
How Does JK Calculate gas mileage?
I have removed my evap and also the whole factory tank and sending unit. It appears to be calculating my gas mileage still though, does it go off a sensor or something by the fuel rail?
Also i have not searched so if this is a dumb question feel free to say way to search retard or whatever, i will not be offended and may be pumped if its a pretty original burn...
Also i have not searched so if this is a dumb question feel free to say way to search retard or whatever, i will not be offended and may be pumped if its a pretty original burn...
JK Super Freak
Joined: Mar 2014
Posts: 1,408
Likes: 6
From: Nashville, TN
I have removed my evap and also the whole factory tank and sending unit. It appears to be calculating my gas mileage still though, does it go off a sensor or something by the fuel rail?
Also i have not searched so if this is a dumb question feel free to say way to search retard or whatever, i will not be offended and may be pumped if its a pretty original burn...
Also i have not searched so if this is a dumb question feel free to say way to search retard or whatever, i will not be offended and may be pumped if its a pretty original burn...
JK Super Freak
Joined: Sep 2012
Posts: 1,564
Likes: 7
From: United States
I think it's a flow rate calculated over miles driven, all calculated by the PCM or ECM and nothing to do with the tank itself. It wouldn't use the sending unit, otherwise your gas mileage would fluctuate when you went around a corner.
Thread Starter
JK Jedi
Joined: Apr 2011
Posts: 4,482
Likes: 2
From: Neenah, Wisconsin
Gotcha, I have installed a hard wired fuel gauge to my fuel cell and that fluctuates around corners as you said, thats what made me wonder. My factory gauge is also wired together with a resistor to always show it as full, i figured it must be calculated some other way.
Last edited by Maertz; Jul 21, 2015 at 03:42 AM.
JK Junkie
Joined: Jun 2013
Posts: 3,697
Likes: 2
From: Grosse Pointe, MI
It's an algorithm that uses the tone rings for speed, engine rpm, etc. There is no actual flow meter. Hence the limited accuracy. Well, it's actually not too far off on stock jeeps. But in percentage terms I wouldn't define it as accurate.
JK Junkie
Joined: Feb 2011
Posts: 2,318
Likes: 12
From: New Hampshire
its put there to make us try to conserve
if it says 20 we try and get it to say 21 if its 16 we try for 17
drive it like you stole it
if its close to being accurate its surprising
( but it really is a good question) my guess would be speedo sensor /odometer
drive it like you stole it
if its close to being accurate its surprising ( but it really is a good question) my guess would be speedo sensor /odometer
Last edited by jeepmojo; Jul 21, 2015 at 05:55 PM.
Trending Topics
JK Junkie
Joined: Feb 2011
Posts: 2,318
Likes: 12
From: New Hampshire
just saw this on a thread
fuel consumption is measured from exhaust emissions not actual fuel usage
10 ??? yikes but 40s lol what could one expect
10 ??? yikes but 40s lol what could one expect
Last edited by jeepmojo; Jul 21, 2015 at 06:03 PM.
Thread Starter
JK Jedi
Joined: Apr 2011
Posts: 4,482
Likes: 2
From: Neenah, Wisconsin
Well this makes me ponder more. I have also removed 2 cats but left the sensors and have alot less back pressure im assuming. I also have no evap system at all. What are the odds its actually close? Its going to be alot easier to calculate from the pump when I can fill my tank full and i get my odometer dialed in a little more.