So if you asked me last week, I would tell you that I would be the last person to open up a MPG thread. The reality is that gas "costs what it costs" and I am still going to have a boatload of fun between "Point A" and "Point B" because whining about pump prices is seriously annoying (read: I drive it like a Porsche with too many wild ponies on a daily basis). So this is my M.O.

With that said, I once was curious to see what MPG I was getting and did some data logging with my Durametric on one round-trip to pickup my wife from work. I logged the starting liters registering in the gas tank, the ending liters, and divided that by the total miles (66 miles total according to Google). I was shocked to get 26.6 MPG considering a did a couple of WOT bursts on the highway!

I chocked it up to the ridiculously tall gearing in the 957 CTT (3.23, I believe) and power bolt-ons. At 60 mph, it barely turns at about 1500 rpms.


Fast forward to today and I see Cole's post here where he shows a picture of his PCM giving him his average MPGs. While being bored at a stoplight, I stumbled upon this PCM menu option (thanks Cole!) and was stumped by what I found (Average 33.8 MPG???):



What do you guys think? Am I missing something here?

 

I'm more shocked that the display shows a CD in use. Didn't realize anyone still used their CD changers . . .

 

Hahaha... good eye! That is actually my Dension GW 500 hooked up to my iPod. It uses the CD changer connection to talk to the PCM and control, charge, and give track information. So actually my CD changer is just a dead weight in the back- like it should be

 

I have my Dension unit sitting in my garage waiting to be installed (also planning to disable my CD changer). With a new to me CTTS, there's too many projects for it and not enough time to get them done as quickly as I'd like.

I'll be fantasizing about your displayed gas mileage, though.

 

NOWAY!! after that ride I took I cannot see you doing that MPG I call defect!

 

definitely hard to believe that is accurate, i checked mine also and it was 12.9 when i got the truck. Driving extremely conservative gets me ~20, any wot makes it plummet lol

 

What is the driving time part of that? Seems like something is messed up there?! The format is wrong.

Maybe the Denison is screwing with something else?

 

hadnt thought about trying math, the hours (that appear incorrect as cole noticed) and the avg speed with km traveled = 33.8 mpg is impossible. And i just noticed its a mix of Km and Miles, also making no sense

 

Something funky about the info on your display.

Here is mine again. (Sorry for the blurry, dusty picture. Took it on a road trip across Nebraska with a cell)

 

any idea why the lack of info for distance?

 

No idea. I'm guessing that it only had 3 digits available and I'd traveled farther than that?

 

possibly, i have only managed about 400 miles on mine so far lol

 

I am not sure to be honest. I never use the PCM navigation since it is difficult (thanks Google Navigation) and haven't reset my battery since I owned it.

I am wondering the PCM thought that the last 40,000 miles was a "continuous" trip? And starting looping back on itself for the mileage and time. FWIW, that average speed looks about right to me - many highway miles. I suppose I could just reset it and check back in after a month or so.

 

do it!

 

I'll have to reset mine too. It's currently got data in it from towing a 7700 trailer for 4k miles.