I wouldn't even look at the average MPG reading until the truck is broken in. These engines are tight, you should see a good improvement after about 1,000 miles. Also, don't do all highway miles, as the rings will not seat as well due to the constant engine speed and low load. City miles with varying RPM is the best way to break it in. As far as towing, I would avoid that, just as the owner's manual says. However a few spirited accelerations won't hurt. You can also use the manual shift function to downshift and let the engine slow the truck down, that is very beneficial for ring sealing.
my new 6.7
- Thread starter 06-sixoh
- Start date
I wouldn't even look at the average MPG reading until the truck is broken in. These engines are tight, you should see a good improvement after about 1,000 miles. Also, don't do all highway miles, as the rings will not seat as well due to the constant engine speed and low load. City miles with varying RPM is the best way to break it in. As far as towing, I would avoid that, just as the owner's manual says. However a few spirited accelerations won't hurt. You can also use the manual shift function to downshift and let the engine slow the truck down, that is very beneficial for ring sealing.
TexAg56
New member
I can tell you that right now I am running the SCT tuner with the canned *** on tunes and Im not too happy. Didnt see any MPG increase and also my truck has thrown 1 code amd as of yesterday she did something weird. I was driving and noticed noooo power. She was in 6th gear and wouldnt downshift when I accerlerated hard! She wouldnt downshift untill I manually shifted down. I turned the truck on and off and she was good to go again. So if you're looking for a *** on tune I would still go custom and not the canned sct tunes. I have Ghead tuning on my tuner that I will be using as soon as I can do my ******s. That will be much better hopefully! Just goving you my experience with the canned *** on tunes
gnxtc2
Active member
Picked up my 2016 F350 DRW on 10/30/2015 and reset the mileage when I pulled off the lot. So far, I have 350 miles on it mostly all highway. I'm at 16.0 with the cruise set at 70.
I'm pretty sure the motor is already broken in at Ford. But anyway, I had the motor under constant boost to seat the rings to make sure. You baby the motor, the rings will never seat and they will glaze over hence the reason for the cross hatch in the cylinder walls. Putting the motor under high boost seats (pressure) the rings real quick. There is nothing to break in on a motor except for the rings. There is nothing to break in on a trans. The only thing that needs to be broken in are the gears in the axle(s).
Billy T.
[email protected]
I'm pretty sure the motor is already broken in at Ford. But anyway, I had the motor under constant boost to seat the rings to make sure. You baby the motor, the rings will never seat and they will glaze over hence the reason for the cross hatch in the cylinder walls. Putting the motor under high boost seats (pressure) the rings real quick. There is nothing to break in on a motor except for the rings. There is nothing to break in on a trans. The only thing that needs to be broken in are the gears in the axle(s).
Billy T.
[email protected]
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dsmracing1
Active member
Your going see an improvement in power within 15000 miles or so in my opinion. I noticed a great improvement in power and efficiency over when I first got my truck. With these trucks having such tight clearances they take a bit to break in. Best thing to do is hook up to a trailer right from the 1000 mile mark and heat soak it good to seat the rings and valves for good break in. Diesels love being worked so work it hard and it will work good for you...
HeavyAssault
Active member
My experiences have shown it takes 20-30k for these motors to be broke in.
Mikeyfitz
New member
Mine was ******d at 278 miles and no regrets lol. 13mpg is fine by me.
I say ****** it!
I say ****** it!
06-sixoh
New member
These are the responses I was looking for, so thank you very much!
Its starting to rise a little bit. Im trying to put as many miles on it as I can, for right now and as colorful as possible. I was a bit "spirited" last night. I ran Matt's files on my 06, and used the SRL+ as my DD. I ran great (when the truck ran), always had great mileage and power at any point. IF I do tune, I will most likely send Lars an email and get a file emailed. I would love to ****** and tune, and believe me, Ive already peeked at some kits. BUT, (Not to compare, because I know the difference) I had so many issues with my 6.0, that's its kind of nice right now having a quiet, dependable, luxurious truck with a premium warranty that will last longer than the loan. So a tuner with smog shtuff enabled will be the most I will do... #famouslastwords Mark 'em.
TEXAS:
Canned tunes are horrible, but I get what you were probably trying to accomplish. For the trans not wanting to downshift is a little weird though. I don't know much about these transmissions, unless they are similar to the 5R, but I put a lot of abuse on my 06's 5R before I had to rebuild it. So hopefully it was just a glich and not a tattle tale of something bigger.
Its starting to rise a little bit. Im trying to put as many miles on it as I can, for right now and as colorful as possible. I was a bit "spirited" last night. I ran Matt's files on my 06, and used the SRL+ as my DD. I ran great (when the truck ran), always had great mileage and power at any point. IF I do tune, I will most likely send Lars an email and get a file emailed. I would love to ****** and tune, and believe me, Ive already peeked at some kits. BUT, (Not to compare, because I know the difference) I had so many issues with my 6.0, that's its kind of nice right now having a quiet, dependable, luxurious truck with a premium warranty that will last longer than the loan. So a tuner with smog shtuff enabled will be the most I will do... #famouslastwords Mark 'em.
TEXAS:
Canned tunes are horrible, but I get what you were probably trying to accomplish. For the trans not wanting to downshift is a little weird though. I don't know much about these transmissions, unless they are similar to the 5R, but I put a lot of abuse on my 06's 5R before I had to rebuild it. So hopefully it was just a glich and not a tattle tale of something bigger.
TexAg56
New member
yup I cant wait to get off this tune and onto the Ghead tunes! I am also comming from a 6.0 and I know exactly what you are saying about having a nice quiet luxury truck lol! huge change and Im so happy with my new truck!
06-sixoh
New member
Im tickled pink. These AC seats have got me spoiled beyond belief. I had plans to mod this truck right when I got it, but Im so happy with the way it runs that Im just going to leave it.
tbsimmons
New member
I dont understand the idea of seating the rings and breaking in the engine in a new vehicle.
The rings are seated by the time the consumer drives the truck if not they wont seat. The only time the rings need to be seated is if you build a new engine. Which happens pretty quick. Let the engine torque break and they are seated.
The other, breaking in an engine, do it the way you are going to drive it.
The whole wait to tow for "X" amount of miles, what are you waiting for?
The trans, well if something is wrong with the trans it will show up instantly while shifting through the gears the first few times.
The engine, if it needs to be broken in before pulling then why only wait to 1000 miles why not wait till you get better mileage.
Diffs, you are not going to heat treat the ring and pinion at all while driving. If the gears are set up wrong then you will know instantly.
I was always told the above growing up in a mechanic shop. It really took hold when I was pitting for late models.
Break a new engine in, practice session seat the rings and then let her have it.
Gears no break in, swap the third member and go run the hell out of it.
Trans, well manual but the same as gears.
Just my thoughts. The 08 450 I towed way early when I first got it, as in first 300 miles or so. The 04 F350 I did gears and towed within the first 50 miles.
The rings are seated by the time the consumer drives the truck if not they wont seat. The only time the rings need to be seated is if you build a new engine. Which happens pretty quick. Let the engine torque break and they are seated.
The other, breaking in an engine, do it the way you are going to drive it.
The whole wait to tow for "X" amount of miles, what are you waiting for?
The trans, well if something is wrong with the trans it will show up instantly while shifting through the gears the first few times.
The engine, if it needs to be broken in before pulling then why only wait to 1000 miles why not wait till you get better mileage.
Diffs, you are not going to heat treat the ring and pinion at all while driving. If the gears are set up wrong then you will know instantly.
I was always told the above growing up in a mechanic shop. It really took hold when I was pitting for late models.
Break a new engine in, practice session seat the rings and then let her have it.
Gears no break in, swap the third member and go run the hell out of it.
Trans, well manual but the same as gears.
Just my thoughts. The 08 450 I towed way early when I first got it, as in first 300 miles or so. The 04 F350 I did gears and towed within the first 50 miles.
tbsimmons
New member
What are you heat cycling. Nothing is going to get as hot as it would when it is being manufactured.
tbsimmons
New member
Well can you? I have heard them all. Gears need to be heat cycled from people. Well how do you heat cycle them if you cant get them hot to temper the metal. The first few revolutions of the rear end will make the gear mesh shiney then if set up correct they are done. You cant get them that hot. If you do there are bearings that will not be too happy. Ever had a trans built before. Let it go through the gears a few times and if everything is good with the shifting then its fine. I have never been told with a built trans (Only thing I have not built) or the guys who taught me gears to wait to do anything.
For the engine if the rings are seated, or better be by the time we get new vehicles, then the engine needs no break in. The only ones I can remember needing break in was with non-roller cams (flat tappet lifters). With roller everything nothing is breaking in. Stuff might start to loosen up a little because of wear, but breaking in an engine no.
New engine....Start up, look for leaks, seat the rings, let her eat.
For the engine if the rings are seated, or better be by the time we get new vehicles, then the engine needs no break in. The only ones I can remember needing break in was with non-roller cams (flat tappet lifters). With roller everything nothing is breaking in. Stuff might start to loosen up a little because of wear, but breaking in an engine no.
New engine....Start up, look for leaks, seat the rings, let her eat.
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Like I said, this convo is just an argument now, and no one wins those 
I'm man enough to admit that this topic is so heavily debated that guys with more knowledge than either of us are on both sides of the fence. I'm in no way saying you're wrong, you're used to built engines, I'm used to heavy equipment, which honestly are sooooo far from each other that I can't throw all those facts down and say: see I'm right, nanner nanner!
TL/DR: Agree to disagree lol
I'm man enough to admit that this topic is so heavily debated that guys with more knowledge than either of us are on both sides of the fence. I'm in no way saying you're wrong, you're used to built engines, I'm used to heavy equipment, which honestly are sooooo far from each other that I can't throw all those facts down and say: see I'm right, nanner nanner!TL/DR: Agree to disagree lol
06-sixoh
New member
At any rate...
Fuel mileage is starting to creep a bit. With approx. 350 miles on the odometer, Im seeing about 14.8-9 on the lie-o-meter with mixed driving, spirited and mellow. So it IS creeping. If it ever gets to 17 mix driving, I will probably just keep it stock. That being said, I have hopes of 20 on the freeway.
Fuel mileage is starting to creep a bit. With approx. 350 miles on the odometer, Im seeing about 14.8-9 on the lie-o-meter with mixed driving, spirited and mellow. So it IS creeping. If it ever gets to 17 mix driving, I will probably just keep it stock. That being said, I have hopes of 20 on the freeway.
What is the instant showing? My instant will get over 20 if I am on a flat stretch of highway. It drops to 15ish when I have to accelerate or go up a hill.
When I brought mine home from the dealer it was an 80 mile drive. It averaged 19 mpg with a mix of speeds from 60-75. At about 250 miles it hit the first regen mileage dropped down to 16.5. It regens about every 250 miles for me. My lie-o-meter says 17.2 right now, but my last tank hand calculated was 15.9. I reset the meter when I left the dealer at 8 miles and not since. Truck is all stock and just rolled 1000 miles yesterday. I picked it up on Halloween. CC/LB lariat 4x4 3.55 rear end.
morepower02
New member
So if u reset what you call the lie a meter when it was new and your last tank hand calculated was lower than the average what's the point? All of my fords I reset every fill up and it's never lied?
Sterling6.7
Well-known member
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Like I said, this convo is just an argument now, and no one wins those
+1
Put a couple more zeros on there and you will be able to grandpa that thing to 20 on the highway. I ran from Portland to Seattle averaging 70 and put down a hand calculated 20.2.
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