The inventor of the Scangauge II says the OBD II port delivers injector pulse width data. I agree it's tougher to measure low fuel flow than high fuel flow, but I was surprised the SC II was only 3.5% high on fuel usage straight out the box against a hand calculated fill and refill to the brim from the same pump. The tank of fuel measured was 70% slow speed city driving and about 15 minutes of SEIC high idle.

You are correct (my mistake - just wasn't thinking it through) for our four cycle engines. Seems that this supports the lower numbers of close to 1/4 gph. That seems low for what I see on the lie-ometer and what the scangauge reports!

I'm very pleased with the trip features of SC2.
I took 41.6 gallons and it estimated I needed 41.4 gallons at the
last fill-up 2 days ago.

I sure hope all the doombsday predictions about letting it idle are wrong. I let mine idle for up to 10 hrs a day depending on the weather. Sometimes I wont hit the road for 3-4 days to clear it out. I hooked up the high idle a month or so back and use it several times during the day. I usually have fill up after the 3rd day of sitting. I guess I can be the long term test dummy to see if if things start to go horribly wrong. Only time will tell.

BTW I drive the snot out of it after sitting for a few days, just in case

Mud

Why is that?

The service guys at my local Ford dealer see a lot of high idle time Wyoming oil field work trucks and have replaced tons of EGR valves.

My truck was the first they had ever seen with the Stationary Elevated Idle Control (SEIC) circuit hooked up. That was five years ago and they started mentioning the up idle feature to their service customers.

To stay warm, cool. I have a small heater that I can plug into a generator when I have a chance. My truck is my MOBILE COMMAND CENTER. :-D

Mud

My XL doesn't have a trip computer, so I set up an X-Gauge to show me the real time tank average MPG. It's more accurate than the Ford Lie-O-Meter I've experienced in other trucks.

Check out Displaying a Trip Value as an XGAUGE on page 28 of your ScanGauge manual: TXD = 04

The name I selected was TAv for Tank Average (in MPG). I'm running it with oil, water and transmission temps. Seeing that moving MPG average helps me save fuel.

I resemble that remark, just in Oklahoma

Mud

I am an ex long haul truck driver. I have found that the big engines run about 1/2 gallon or less an hour. Another driver in here mentioned the old rule of thumb being 1 gallon an hour. I have never found a truck that used that much and I ran Cats. If it is extremely cold and you would like to use the truck the next day. I suggest letting it run. Block heaters will not warm fuel, but leaving it run will circulate fuel into the pump and out the return. I have been out of trucking and my Powerstroke is "seasoned" enough, I have never had to deal with an EGR valve. I do know that emergency vehicles run all the time. Some ambulance services just switch crews and the trucks run 24 hours a day. In the cold, even if I do plug my truck in. I either let it warm up, or take it real easy until it does. Cold thick oil and high RPMs will break things.

I also would rather buy a high mileage truck VS a low mileage truck with lots of idle hours though. Everything in moderation.

One of the best post on the rather emotional and religious issue on idling.

IMHO, idling often do a lot less harm than the alternatives.

Or, it is just needed to run accessories.

Key point you make: warming fuel --- very important in extreme cold.

Another thing on the idling is that it will help to warm the transmission (slushbox) and the accessories on the front of the engine. Two things that the block heater wont do.

I have a 7.3 but found this thread interesting. My Diesel Mechanic told me to always plug in at anything below -10C which is about +14f, and idle for at least half an hour before I drive. If the oil is sludge you will harm your injectors.

I have the high idle, it idles at about 1200rpm when cold, now I wonder about my idling practices? I don't have EGR. I own an Excursion so even with the heat on front and rear it takes a long time to heat up all that space lol and for me its about getting into a warm truck with warm fluids (Oil & tranny).

Of course my idle in -15c to -20c is about 10 to 15 minutes but when it gets down to -55c that's -67f I get closer to 20 min of idle time, my command start is set to 24 min. The Diesel setting actually gives it a longer run time then having it set to gas mode.

My other thoughts. Ever driven through a truck stop in the north in the middle of the night. Every rig is running and idling all night long.

personally extended idling unless you actually are in the truck on a jobsite is a waste of money. not only will you pay at the pump, you will have other maintenance issues sooner or later. Anything over 1-5 minutes in the morning is STUPID unless you are putting a newborn child in the vehicle. at -10f i don't usually plug in. fire up the engine with the fast switch on(5 seconds after startup its at 1200) sweep of any snow,scrape windshield and just accelerate slowly and gently. most of California does not have the first clue what cold is. if you do have to get on it soon after start up plug it in for that 1-2 hours before, and you can safely get on it much more so.