How are your cold starts going? 10F isnt super cold but under 25 and my 7.3 is pissed. The 6.7 only fired the glow plugs for about 3 seconds and started right up without a flinch.

I love the way the 6.7 sounds when it's cold. It needs to always sound like that.

 

It was about 4 here this morning and colder with the wind. I did not have her plugged in and also did not drive her for a few days. She fired right up!

 

We've been between 0 and 25 for the last couple of weeks and I am yet to remember to wait for the plugs and it starts the same as when it was summer. Just warms up slower.

 

I agree about the way it sounds cold!

The glow plugs were on for much longer than 3 seconds; the wait to start light operates independently of the glow plugs. PowerstrokeHD posted that they are capable of remaining on for up to 20 minutes! These glow plugs go from 0 to 2,200 degrees in less than 2 seconds!

I've done cold starts as cold as -5° so far without plugging it in, and it starts as easy as it does on a warm summer day. I've been plugging mine in with a timer set for 3 hours hopefully to save some fuel, this thing burns a LOT of fuel when it's cold!

 

I noticed the same thing. Until it finally starts warming up, it is very thirsty.

 

sooooo if you want really lousy mileage just leave it sit there sucking the juice, instead of driving it fairly soon after starting it.

 

Crazy - Do you verify the increase in fuel use by monitoring the average MPG? The reason for asking is that my instant MPG indicator has no bars if idling. Thanks.

 

I verified this through several different ways.

First of all I don't allow my truck to idle to warm up. It's -5° F out right now, and like I always do I will start it up, pull it out of the garage, get out, close the door, and start driving. I take it easy on the throttle until it warms up, but I do not spend much time idling.

I usually reset my MPG counter before I start the truck, so I have a good idea how I do on each specific trip. My commute is 43 miles each way on rural highways, so I normally do pretty well. When it's below 10° I seem to average in the mid 17s.

Now if I reset my MPG counter after I get up to speed following a cold start I usually see about 1 MPG better across the entire trip. This is because after the first few minutes I can look down and see between 6-10 MPG; this is as good as it gets when it's this cold until the engine warms up!

Once above ~100° EOT the engine seems to run as efficiently as it always does.

I'm tracking fuel consumption per tank as well, and the last two have been between 16.5-17.5, which is well below average. I just started using the block heater for three hours each morning to see if I see an increase in MPGs. So far so good, I'm at 18 right now!

On edit:

Here's every fill-up for the last 1,826 miles. I'm tracking every tank now:

 

Thanks for the clarification.

I read "somewhere" that "someone" said letting the 6.7 idle for 1 hour uses the same amount of fuel as driving 25 miles. Not sure how they came to that conclusion, if it varies by temp. or just an urban legend.

 

i have an 03 6.0 with 191,000 miles on her now and i get decent milage with the old girl,but starting it up and letting it warm up is an expensive thing to do.best to fire it up ,let her smooth out and drive her slow.

 

i used to commute 60 miles each way. it didn't matter what i drove 1 of the 2 intrepids or the F350 mileage kept improving til between 10-15 miles. first off we know at least in the older trucks its just an idiot gauge, so it my not really be fully hot when the needle first hits the normal spot. 2ndly all the other oils are still cold and stiffer than they will be at full operating temp. the motor oil prob heats the fastest and it alone can take twice as long as the coolant. now the trans,transfer case and the diffs, way long. and idling won't put any heat into the diff, and very little into the trans.

 

I believe engines with piston cooling jets and water-to-oil oil coolers heat up much faster.

My truck has an engine oil temp gauge on the info screen, and my EOT is always within 10° of the coolant temp.

It still takes forever to warm up from an idle though...

 

This morning it was -22*F and the truck started right up with out any issues. It was not plugged in either. It idled up to about 1100rpm on its own. I let it idle for about 3 or 4 mins before I drove a couple miles to get fuel. When I put it in park it idled at 1100rpm for the whole time I was filling up and then by the time I got to work the idle was normal again, but the temp gauge never completely reached normal temp on the 20 mile drive.

 

thats exactly what my early 03 has been doing for 190,000 miles with no problems .1 icp and 1 alternator. it's been bullet proof.

 

Well, you could start the truck with the Trip A screen on the display. Idle it for an hour and see how many gallons of fuel it tells you it used. Standard thing I have always heard is 1 gal/hour.

It does sound good when cold. I also agree that the cooler air equates to more fuel usage, even over long drives.