is there any sensor that can measure fuel consumption/mileage in ml/sec or like ml/km then display it on a gauge meter in real time. they should already invent it by now but i cant find it anywhere on the web. its been frustrating searching for it.

i only found obdII monitor but it cannot specifically monitor fuel consumption rate. and if there is any way to calculate it from the availaible reading there is no way to measure it accurately enough.

 

You can calculate it if you know the injector duty cycle, injector size, and fuel pressure.

 

I've thought of this too, and unfortunately there's not a real simple way to directly measure the fuel flow rate. A pretty good way is to use a vacuum gauge calibrated to the fuel maps and use it to display miles per gallon, or kilometers per liter, in your case. I think this sounds familiar... oh yeah... BMW uses this.

 

practically i would be able to know the injector size from the manufacturer. duty cycle? is it same thing with injection duration. duty cycle is determine by ECU right. but the question is: is the duty cycle and duration monitored by OBD. And if it is possible to calculate is it accurate.

 

I guess there is no retail of that BMW mileage gauge and sensor in the market. How come no-one thought of selling a sensor and a gauge measuring fuel rate for any fuel-line of any car.

 

The duration is monitored and readable in OBD2. You can use it to find the duty cycle.