PorKen

Got this off eBay for pennies. I didn't realize this was a ROW option only, M255, until after I bought it! (Is there an MPG version?) My US 86 glovebox manual doesn't mention it, although it is visible in one of the dash pics.

I think it's cool, and fills the empty space on the tach. Installation was easy as it is already wired for it.


I am having some trouble remembering the conversions, L/100KM-MPG, 5-47, 15-15.7, 25-9.4. Most of the time it's at 25, the way I drive.



I only had two extra bulbs left for the PRND32, so I replaced the P and D. Of course, after it was installed, the 2 doesn't work. I want to replace the foil, so it's coming out again, anyway.



The 'computer' has four inputs, injector pulses from the LH, speed, RPM, and coolant temp. The coolant temp surprised me. The gauge doesn't do anything until the speedo shows over 5 mph (which made me think it was broken, after I installed it), and on decel, the injector pulses drop out, so it goes to 0, too.

BTW, AFAIK, 85-88 can interchange instruments - the circuit foil is the same part number.

Schocki

There should be a MPG version. Roger's Weissach has this gauge with MPG.
When you stop does it still show something?

PorKen

I forgot to say, ROW after 85, AFAIK. The gauge was a US option 82-84.

When stopped, the gauge goes to zero in several jerky steps.

PorKen

Notice also, while I had the instruments out, I spent about an hour scraping off the [Unleaded Fuel Only] sticker - with my thumbnail - so as to not scratch the plastic. Torture! But, it looks so much better.

heinrich

SON OF A !@#$^%& I've been sitting on one of these for YEARS, I asked this question a billion times, what is needed and was told the brains would not power it so I never installed it.

Richard S

But how will you know what kind of fuel to use?





Rich

PorKen

Once the reactors are )(orcised, the point is moot.

D_Schultz

That's weird - the gauge in my euro '83 sits right around 14 when I am sitting at idle after the car has warmed up.

PorKen

Hmmm. I wonder there's a problem with my gauge (or circuit foil, etc. - I still have a wonky gas gauge), or if the 85- has different circuitry.

Schocki

The gauge turns to consumption per hour after you come to a complete stop. My guess would be 1.4 liters per hour....

Thought behind it was to keep the owner informed about the amount of gas used while at idle.

Jebjerg

Can you pull the data/input for the L/100KM gauge from a 928 S MY81 ROW model?

ramcram

I've just bought an '85 cluster with one of these fuel consumption gauges in it. The tacho is for a manual [no gear selector positions] and my 2 cars are both auto, so I don't know if I can be bothered with it.
Is there a wiring diagram for the consumption gauge circuit?

TM___

Probably long overdue, but I'm looking for a tacho with fuel consumption gauge for a manual car. The one shown above, going up to 25 liters without the l/h alternative (like in the older model years). Also without the automatic gear selection indicators. A new one from RosePassion is around €500, but I'm not willing to spend this much just to see how much fuel the car guzzles.

Anyone has something lying around?
@ramcram maybe?

part number would be 92864196510 if I'm correct. (928 641 965 10)

(My car is an '84 Euro, twin distributor, manual 5sp.)

olmann

I'm sure I have one. I can check later today

olmann

Hmmm. Well, it looks like the one I have is for an auto. I must have used the manual one sometime back.