Aftermarket MPG Gauge?
 

My F250 6.0 Diesel did not come with a Lie-O-Meter so I was interested in an aftermarket MPG gauge. Does anyone have any recommendations?

I got a scangauge. It doesnt work worth s**t. I bought it for that purpose. For some reason it stops monitoring MPH so it cant calculate MPG. The GPH works good though and I use as an instantaineous indicator. Also monitors coolant temp which I think is useful and is a code reader too.

The only thing that really works is really expensive flow meters.

The NGS scan tool with give you a good camparative idea as to what conditions will give you the best mileage, but that's about it.

Does the scangauge display fuel pressure? I was thinking this would be an easier than plumbing in an actual gauge.

On my scangauge there was a setup screen where I had to choose between a few fuel options, something like gasoline, diesel A and diesel B. I didn't know which diesel setting so I tried one of them and it didn't work. By default the other works great. I don't think there is a readout for fuel pressure.

On the NGS there is a PID for "Instant Fuel Economy".

It displays in MPG (yeah, whatever), but is actually very good at finding the mileage sweet spots and troubleshooting low mileage areas while live tuning.

Of course, for the 6.0 you won't be able to live tune (unless you work for Ford MoCo), but you'll still be able to use it as a tool to help tune for improved mileage.

It is Gal per hour. It gets this reading from the OBD2 port so the computer is calculating this somehow. As Vic said it is a good reference tool to determine the efficient operating spots for this engine. The reason mine doesnt work is not because of the fuel side but because it displays 0 MPH about half the time so my average always gets screwed up. Maybe I got a bad scangage or my OBD2 port has a weak signal? Overall it was not a lot of money and I like the ability to monitor my coolant temp in the winter on it. 50C on the scan gage is where my dash gauge starts to move. A lot of people on here will tell you wait for the gauge to move as a warm up indicator. The are wasting time and fuel on that because 50C is plenty warm befor starting to dirve. Check out a cost of a OBD2 code reader, a very handy tool and this does that too, just download the codes off this site and take put them in the truck and you will always know what is wrong with your truck as soon as it happens.

Are you using an NGS+ ?

I got the Gen I version of this:

http://www.scangauge.com/

Unfortunately for me only about 3 months ago immediately before this came out. At least I paid less.

I just use the old fashion method for calculating mpg. There's a reason they call it "lie-o-meter"