доверять, но проверить

[Fifty150]

I see that some people are reporting great mileage.  Mileage which is displayed on the vehicle dashboard.  I have always used the old fashion method of miles driven, divided by amount of fuel consumed.  

 

No science here.  I went from full tank baseline to the next fuel refill.  I just decided to use my tablet computer to read the OBD II port to see what the vehicle's computer sees.  An Amazon Fire ($35) with Torque Lite (the free version).  So I'm reading the same display as what most of you are reading.  According to the car's computer, I'm getting great mileage.  The last tank was 28.5 MPG.  But in the real world, I drove 177.1 miles, which consumed 11.385 gallons of fuel.  15.555 MPG.

 

You guys can believe what you want.  Truth is, some people must be getting the great mileage estimated by the car's computer.  Just not me.  And apparently, I'm not alone.  Others have also reported poor mileage.  

 

Anyone else looking over the fuel purchases and comparing it to the odometer?

Edited December 14, 2018 by Fifty150

[Don Ridley]

Maybe this will work?

https://www.focusst.org/forum/focus-st-performance/28685-have-you-heard-turbo-transformer-tuning-device-5.html#/topics/152395?page=1

[Dandytc]

On 12/14/2018 at 3:30 PM, Fifty150 said:

Anyone else looking over the fuel purchases and comparing it to the odometer?

 

 

I did when I first got my wagon. The discrepancy was not too bad: 19.5 MPG real life vs 20.4 MPG computer reading.

Not nearly as good as the 28 MPG range reported by some on this forum, but I do a have a heavy foot, and do very little long distance highway travelling, which would substantially alter my readings, even without changing shoes.

[Dandytc]

Trust, but verify. Thank you Google. And thank you Fifty for the challenge.

[Fifty150]

Nobody remembers Reagan saying that all the time?

 

[Fifty150]

4 hours ago, Dandytc said:

 

even without changing shoes.

 

 

I could go up or down in height by 1/2" when I change shoes.  I remember Prince use to wear those high heel boots because he was so short.  I'll tell my "when I met Prince" stories some other time.

[WillMartin]

I don't believe much of anything, but I don't know how to prove the odometer reading one way or another.  Being a bit of a geek, I do the math in my head based upon a reset trip meter after every tank of fuel and whatever the pump tells me I put into the tank.  Both are probably a little off, but close enough for jazz.  Nowhere close to 28 MPG, but so far, more than 20 mpg.  I'm pretty happy after feeding a full size van.

[mrtn]

My dash display is accurate in the range of 0.1-0.2 liters/100 km compared to the fill-up method. Which is pretty good, IMHO.

[Eddy Kilowatt]

Here's what Fuelly.com reports, for about five thousand fillups of Ford Transit Connects with 2.5 liter four-cylinder gas engines.  So there's obviously a huge range, close to 2:1, in the actual fuel economy that folks are achieving.  They don't report what folks' trip computers are reading.

 

I've only had my van long enough for one fillup... so no real-world data from me, yet.

 

[WillMartin]

I have had mine for about three months and three tanks of fuel.  The best calculated mileage was almost 25.  The worst calculated mileage was just under 21.  It's a 2010, so it has no displays about anything.

[Fifty150]

It also depends on who is doing the reporting, and their driving styles.  I doubt if any fleet users have an employee posting their numbers for the entire fleet.  So anyone who drives 8 - 10 hours a day, low speed, engine idling, stop & go....is for the most part, not reported.  Guys like me who get very poor mileage, are not represented in those statistics.  

 

I see that someone reported 10 MPG.  

[WillMartin]

Last fill up - 21 mpg.  I was expecting a bit more, but then that tank included hauling PA gear and some other heavy stuff.  The van was stacked to the ceiling with equipment.  It did just fine, which made me happy.

[Fifty150]

Just interesting that the window sticker mileage is an "EPA" mileage estimate.  I suppose that's true with every vehicle.  Real world driving varies from person to person.  We all have different driving styles, and road conditions.  

 

I have never personally seen the window sticker mileage on any car I've owned or driven.  

 

Didn't MythBusters do a few episodes on mileage?

[Fifty150]

 

[foof]

21 hours ago, Fifty150 said:

Just interesting that the window sticker mileage is an "EPA" mileage estimate.  I suppose that's true with every vehicle.  Real world driving varies from person to person.  We all have different driving styles, and road conditions.  

 

I have never personally seen the window sticker mileage on any car I've owned or driven.  

 

Didn't MythBusters do a few episodes on mileage?

 

The EPA test is a standardized test route.  I forget the details of it, but it's changed several times over the decades.  Most of the changes were to make it more realistic, but it's still done on a stationary dyno.  Tailpipe analysis is done to measure fuel consumption (count the carbon atoms, basically, which tells you how much fuel when in.), they don't rely on the gauges or a refueling system. 

I've had cars that I routinely beat the EPA numbers on (at least on the highway), and cars that were much much worse. 

[mrtn]

EPA test figures are beatable as it’s a more real life scenario. You can never beat or match NEDC figures as it’s a lab test designed to get into The Guiness Book of Records.

[WillMartin]

I usually beat the EPA city estimate and don't beat the EPA highway estimate.  Combined is a crap shoot.

[WillMartin]

The latest tank was a 24 mpg (US gallons) tank even with the boneheaded driver turning off O/D for about 50 miles.  I can imagine it may have got closer to 25.  After a Chevy Express, I'm completely happy with the fuel economy it gets.