i was in my girlfriend's jetta yesterday and i was looking at her dash and there is a little display that gives the fuel mileage and outside temp (among other things). my question is this...is it possible, or has it been done, where someone has put something like this in their car? i know there would need to be sensors installed and all that. but i was wondering if it had been done and if so what kind of work it took.

 

SS122,

Yes, it's been done mant times - on newer cars. My wife's Astro has the same thing, as do many other vehicles. They've been around since about '93 or '94 IIRC. The display gets data from the PCM to calculate the predicted range, instantaneous mileage, total fuel used, overall fuel economy, outdoor air temperature, and approximate direction (compass). The older ECMs in our cars cannot pass through data like that to the factory displays, but I'm guessing there is an aftermarket device that can (other than TunerCat or laptop software).

 

I'm sure it could be done, it's just a matter of how much work you would be willing to put into it. Also, I wouldn't say that it is a new thing, my 82 t-bird has that option, but it wants a new fuel gauge sending unit, and it doesn't like to work, it says that I'm getting 255 miles per gallon (I wish).