I am looking for a digital monitor system that reads fuel economy. I was looking at the quadzilla scout and have discovered that does not read fuel economy. Is there one available that does on a 2004 dodge.
Thanks

 

I'm not sure of any systems that read fuel economy, unless they pull it from the ECM/PCM like the overhead console does. At with that system, the economy reading is a scientific guess at best and loses all accuracy with any modifications.

 

I know I was amazed that my Jr. changed the overhead display from 10.5/11.0 when towing to 14.5/15.0 or so. Hand calculated...still around 11.0/11.5!!!

 

I would guess you best bet would be something for boats, that is a GHP meter, but you would have to calculate you MPH into that to get the reading your looking for...

 

Scangauge II connects to the OBDII port & like others have said it will not be accurate as far as MPG are concerned, but it you know how much they're off by it will be a good estimate.

 

Our trucks don't transmit accurate data thru the OBD port so no OBD reader with MPG's will be accurate.

 

Yeah... I have a ScanGaugeII also. I bought it back when I had my Tundra and also use it to check engine codes on our Honda. The instantaneous MPG reading is all over the place with my '05. I don't mean by 10%-20% either.... I mean one second it reads 235mpg, 105mpg, 33mpg, 45mpg, ect.... The only time I've seen it show something reasonable was when I was towing my camper and my boost is up say 25psi range. It did work great with my Tundra and my Honda minivan... I get reasonable numbers depending on my throttle load and can use it to find the 'sweet' spot. Not so with this Dodge.

I do use it in the Dodge though to show me intake temp, water temp, MAP (boost), and RPM's. I know the truck has a tack and a water temp gauge already, but it's nice to see exact small changes in these numbers that you can only see in a digital read out.

Other than that... I wouldn't buy it for those usages alone if you don't have another car/truck it would work in. I swap it out between mine and use it a lot as and OBDII code reader in mine and my friends cars.

 

The problem with a fuel economy number is that these engines do not have actualy flow meters on the engines of these trucks.

The ones that do show that data, they get it by doing a calculation as defined by the OBD2 standards.

Basically they take a bunch of other readings and do some math and then tell you how much fuel they think you should be burning.

It does not work at all.

 

The ECM knows more accuratly how much fuel is being burnt, but the ECM doesn't put that info thru the OBD2. The Diesel Liberty was the same way and they were getting faulty emissions readings so Jeep had to reprogram the ECM (since its a car not a truck).. so becuase we have trucks until the EPA mandates emissions readings there won't be an ECM fix..

I have had my Scan Gauge 2 (OBD2 reader) on several rigs that don't actually have a flow meter, and the mileage is very accurate.. its just these Diesel's it doesn't work in.. In fact it works fine on the 2nd gen CTD's.