Fuel Totalizer Accuracy

[Flying68]

Has anyone noticed that that their fuel totalizer in city driving is off by 0.5 to 1.0 gallon over the course of a tank? When I took trips with a lot of constant highway driving, the total fuel used matched pretty close with the gallons added, especially over the course of a 1200 mile round trip. The last three fill ups that I have had doing city driving have all been off from 0.5 to 0.9 gallons. This affects the computed gas mileage as well.

I have a theory that at idle, the fuel flow measurement is off a lot, which is why city driving would make the system read low due to the extended periods of idling. I also noticed it gets real bad if I do a remote start warm-up.

Thoughts.

 

[chaneya]

I also noticed it gets real bad if I do a remote start warm-up.

Thoughts.

That's a pretty good summation right there. I noticed on an H2 that if I did a warm up (sometimes I'd jump the gun and run it for 30 minutes before driving), that my mileage would total out to less than zero. I think if you want to have a more accurate picture of fuel consumption, you need to shut it off and start it back if you've done a warm up.

 

[cmdrivan]

I've seen (and been following) a few threads about this. Most of my driving is 40% city, 60% light highway. My difference in fuel fill-up and fuel consumption reported by the computer is slightly larger than yours--about 1 to 1.5 gallons. In a recent trip that was mostly highway and interstate with little idling and no remote starts, the difference was smaller--about 0.5 gallons.

My posts are here and here.

_______________________________________________________________________________
2012 Ford Explorer Limited 4WD | 302A | Moonroof | Crossbars | Tow Package | Splash Guards
2007 Ford Focus SES ZX4

 

[peterk9]

I noticed on an H2 that if I did a warm up (sometimes I'd jump the gun and run it for 30 minutes before driving), that my mileage would total out to less than zero. QUOTE]WHY 30 minutes? A complete waste of fuel and completely uneccessary, not to mention an extended idling period does an engine more harm than good. When I was still going to work, even on Winter mornings, I never let the engine run more than a minute or so before driving off.
Many cities/towns in the province of Ontario actually have passed Idling Bylaws to help reduce emissons. While there are a few that limit it to 5 or 10 minutes, the majority have a limit of 2 or 3 minutes.

Peter

 

[jonredcorn]

I noticed on an H2 that if I did a warm up (sometimes I'd jump the gun and run it for 30 minutes before driving), that my mileage would total out to less than zero. QUOTE]WHY 30 minutes? A complete waste of fuel and completely uneccessary, not to mention an extended idling period does an engine more harm than good. When I was still going to work, even on Winter mornings, I never let the engine run more than a minute or so before driving off.
Many cities/towns in the province of Ontario actually have passed Idling Bylaws to help reduce emissons. While there are a few that limit it to 5 or 10 minutes, the majority have a limit of 2 or 3 minutes.

Peter

I wake up every morning and let it warm up for 15 minutes because

:exporange :JP: MURRRRRICA!! :JP: :exporange

Murrica. Emissions are no concern in :rangergreen: Murrica :rangerred:

In all serious though, I didn't know that. Thanks for the info.

 

[dco43054]

look back a couple weeks. Someone started pretty much the same thread.

 

[chaneya]

I noticed on an H2 that if I did a warm up (sometimes I'd jump the gun and run it for 30 minutes before driving), that my mileage would total out to less than zero. QUOTE]WHY 30 minutes? A complete waste of fuel and completely uneccessary, not to mention an extended idling period does an engine more harm than good. When I was still going to work, even on Winter mornings, I never let the engine run more than a minute or so before driving off.
Many cities/towns in the province of Ontario actually have passed Idling Bylaws to help reduce emissons. While there are a few that limit it to 5 or 10 minutes, the majority have a limit of 2 or 3 minutes.

Peter

Peter, relax. You didn't notice the part where I said I "jumped the gun"? Usually that indicates a mistake, in other words - unintentional. Oh wait, you did notice it because you put you parenthesis in front of it - so clearly you're just being rude. Besides, off topic. The point is, with idle time included, clearly fuel consumption is misrepresented. You sort of just changed my entire opinion of Canada with your high and mighty rant. And now, I want to drive to Canada and let my car idle in your driveway until it has burned a full tank of gas.

 

[Joe Dirt]

look back a couple weeks. Someone started pretty much the same thread.

That pretty much summarizes the whole subfor... er, nevermind.

 

[peterk9]

Peter, relax. You didn't notice the part where I said I "jumped the gun"? Usually that indicates a mistake, in other words - unintentional. Oh wait, you did notice it because you put you parenthesis in front of it - so clearly you're just being rude. Besides, off topic. The point is, with idle time included, clearly fuel consumption is misrepresented. You sort of just changed my entire opinion of Canada with your high and mighty rant. And now, I want to drive to Canada and let my car idle in your driveway until it has burned a full tank of gas.

It wasn't intended as a rant and I apologize in that I misinterpreted your wording, "jumped the gun". My bad.
I don't know how the electronics take idling into account in the overall estimates. I did find some interesting info though that members may be interested in.

http://www.consumerenergycenter.org/myths/idling.html

Peter

 

[chaneya]

It wasn't intended as a rant and I apologize in that I misinterpreted your wording, "jumped the gun". My bad.
I don't know how the electronics take idling into account in the overall estimates. I did find some interesting info though that members may be interested in.

http://www.consumerenergycenter.org/myths/idling.html

Peter

I apologize too. That response was out of line, I'm cranky.

 

[GWA1]

Glad you girls have made up!!
I, for one, feel a whole lot better now.

 

[Flying68]

I guess I should explain why I started this thread. My previous vehicle was a 2004 Lincoln LS. The trip computer was always withing 0.2 MPG of what I computed by hand. Our 2006 Murano though is always off by at least 1 MPG. The majority of my initial driving in the Explorer was all highway and the MPG readout was pretty close on each fill-up and over a whole trip was within a couple tenths on MPG and within 0.5 total gallons. For the life of me I can't figure out why it is so hard to monitor fuel flow.