mpg L/100km gauge

[jtanguay]

Anyone know where to buy a gauge for this?  I'm guessing best place to put it would be on the hose going to the pump.   Doesn't have to be digital either, in fact I would rather mechanical

thanks

[vwmike]

Anyone know where to buy a gauge for this?  I'm guessing best place to put it would be on the hose going to the pump.   Doesn't have to be digital either, in fact I would rather mechanical

thanks

I don't think that would really work. The amount of fuel going through the feed line is not only what is consumed by the engine, but a large amount is also returned to the tank. So, you'd have to use 2 gauges and then calculate the difference to find the quantity consumed.

Why not just fill up, drive for a while, then fill up again and calculate how much you used during that time?

[Mark(The Miser)UK]

Anyone know where to buy a gauge for this?  I'm guessing best place to put it would be on the hose going to the pump.   Doesn't have to be digital either, in fact I would rather mechanical

thanks

I don't think that would really work. The amount of fuel going through the feed line is not only what is consumed by the engine, but a large amount is also returned to the tank. So, you'd have to use 2 gauges and then calculate the difference to find the quantity consumed.

Why not just fill up, drive for a while, then fill up again and calculate how much you used during that time?

There's probably a proprietary thingy already out there ... But if I wanted to invent something I'd probably put some sort of vane meter in the uptake to the filter. I'd also have a 2 way valve to redirect the return back to the pump. Have this  remote switchable and coupled with a relay powered indicator on yer dash [instrument area ?]  Probably run backwards for a while as pumped  return fuel 'grows' then as steady state approaches you'd get a reading. Perhaps get clever and add a time delay to the display start-up to avoid seeing -ve fuel consumption :shock: ...
 :wink: But I'm not about to invent this  :wink:
I use Mikes Method which I work out in my head as I leave the pump; miles divided by litres  multiplied by 4.54 gives mpg UK  For 'Stan's wine gallons  x by 5/6....  Any deviation from the 'norm' ( poor that is) is lodged somewhere up stairs incase next fill repeats and tells me something has changed with my engine or mechanics . In fact I lodge good scores too; like 60.24mpg [imp] going North to Yorkshire last year :mrgreen:

[VWRacer]

Hey, I usually get a week per gallon of wine! :mrgreen:  :mrgreen:  :mrgreen:

[srivett]

I asked my friend this and he told me to buy a PD TDI and order a dash from Europe.  NASCAR had the mechanical fuel meter briefly so it has been done.  

Steve

[QuickTD]

I can build a meter, for a price. All the hardware that you need is available from industrial instrument companies. You need two digital flowmeters, one in the inlet to the pump and a second one in the return. Then you just need a triple input scaleable up/down counter/ratemeter with simultaneous anti-coincidence add/subtract counting capability. I priced this scheme out once, I stopped adding at about $3000.

 A more realistic approach would be to use a marine diesel fuel flow meter, they are relatively cheap (some are less than $1000) and are designed to perform the task. They use 2 flowmeters and are equipped with the proper add/subtract counting hardware. I'm not sure if they have a speed/distance reference though. Most of them read in GPH or LPH. You might have to do some quick math to get MPG on the fly...

 My lincoln mark VII turbodiesel had a trip computer that was able to calculate MPG in real time. It used a pintle lift sensor on one of the fuel injectors. It calculated injected quantity based pintle lift, duration and frequency (RPM) and got its distance input from the vehicle speed sensor. The thing was deadly accurate, though I don't fully understand why...

[fspGTD]

There is (was) a readily available product that was aftermarket... I'm think it was a mid-80's thing... that tapped into the fuel supply line and also measured vehicle speed and could calculate fuel mileage exceptionally well.  I recall know there was an option available for it to add a second fuel flow sensor so it would be compatible with cars that had fuel return lines (like a VW diesel.)  I wish I could remember what it was called...

[jackbombay]

I read here somewhere about a set up that used to flow meters and GPS input for speed to get the MPG. I can't remember what he used to do the math and display the number though.

[VWRacer]

Here's what you are looking for: http://www.porcine.com/gps/mpg/mpg.html

Here's another: http://www.floscan.com/html/marine/models/multifunction/series9000.html

And for a stand-alone system designed for cars, try the OZMeter[/u].

[jtanguay]

hmmmm so basically I need one of those flow meters on the line going to the pump, and the return, and then calculate that with the amount of KM I went.  (don't need anything fancy, hell I'm driving a diesel lol)

[Mark(The Miser)UK]

hmmmm so basically I need one of those flow meters on the line going to the pump, and the return, and then calculate that with the amount of KM I went.  (don't need anything fancy, hell I'm driving a diesel lol)

 :shock: Your heart is set on it but not your wallet; :twisted:  so use a flowmeter on the supply and that 3 port valve I mentioned before.
Isn't there a fuel filter that recycles? Peugeot or something? :?:  
:mrgreen: Maybe it can be pilfered from a Greasel setup :mrgreen:

 :twisted: Just get your teeth stuck in and the problems will all disappear;  :shock:   especially when lots of clever heads ar all furiously being scratched at once :lol: