Hey guys, I hope this is the place for this question, Looking for honest answers no matter what they be. I have a 08 job 3 6.4 with 174k on it. very healthy truck, not deleted, fully stock and very well maintained and runs like a kitten. My first diesel in a pickup. I have used this site extensivily to help further my knowlage on my Beast, and which has helped me to decide to leave things stock as well, Local epa laws as well as cost vs means.

My question is, whats diffrent between the 6.4 and 6.7? Power, dependability, did they go back to a single turbo, what problems has the 6.7 had compared to the 6.4, those that are the same and those that are diffrent.

Here is what I do know across the board, Using only Motorcraft oils, coolants, filters, etc you cant go wrong. Each to their own I know in regards to oil brands, deleting and tuning. I service mine every 3k and fuel filters every 6k, due to I dont drive 5-6k pr year. Call me maintance paranoid if you will.

From what I have read in these fourms, the 6.4 does wake up when deleted and tuned and provide great power and mpg, however the downside is the heat that is produced the 6.4 cannot get rid of therefore the piston cracking problems. It is also my understanding that yes the emission crap chokes these engines down, but that the powerstrokes, all of them, cannot really handle the tuning that is being installed, well maybe they can handle the "common sense mild tuning" but some of the high end HP tuning they cant handle like the Cummins can.

I am toying with the idea of upgrading in the near future to 6.7 but also the Cummins is very appealing as well. However my better half keeps telling me if its not broke, don't try to fix it. You know what you have. Besides a new Paint Job would be so much easier on the pocket than a new $60,000 rig.

So If you folk will, could you educate me on the diffrences, benifits, or pitfalls.

Thank you all in advance.

Jay

 

I had an 08 6.4 and now have the 13 6.7 (34,000 miles), I really like the power and mileage improvements of the 6.7. I average about 2 MPG better with the 6.7 over the 6.4 and the power increase in noticeable.

Both the 6.4 and 6.7 have had radiator problems, I had it replaced on the 6.4 but so far no issues with the 6.7.

There was some issues with the early build '11 6.7, the later '12-14 have been solid, and the '15 and up 6.7 have the exhaust brake, which I have not been able to see in use, but would like to have when I am pulling the trailer around. The '17 have more power again and a new body style, and a new price $$$.

After having my 6.7 I wouldn't want to go back to the 6.4. Just a simple view of my experience.

Leon

 

I had an early build 2008 6.4 and it ran trouble free for about 60Kmi. The Fuel consumption was not so good at around 13MPG unloaded. I traded it in on a new 2011 6.7 and immediately noticed a 3-4 MPG increase over the 6.4.
The 6.7 also has more Power. I had almost paid off the 2011, and would have kept it but was worried about the early 2011s eating Valves and destroying the engine. I ultimately traded the 2011 for a 2016 which I plan to keep.

 

When Ford got tired of the problem with the outsourced Navistar (I think) diesel engine they began making their own 6.7. There is no comparison in power between the 6.4 and 6.7.
After the first couple of years with 6.7 turbo issues, ie: some dummy thought it would be a good idea to use ceramic BB's in that turbo then they all turned to dust. Ford has corrected that problem. I have heard of random radiator problems but not rampant so far.

 

Ditto on jumping out of my early build (04/2010) 2011.

Ditto on the 6.7. 6 speed great.

The exhaust brake on the 15 up makes it a much better tow vehicle.

Every step a step up.

I would try for a left over 16. Leave the new model year hassle to others.

Good luck.

 

I had a 09 6.4 deleted, put 100k on it. I think I was running about 50hp more, can't remember but the 6.7 just tows better. But I really liked my tuned 6.4 and wish I'd have kept it for a farm truck.

 

Man all this info is great, I almost sprang for a 2015/16 Dodge dually a last year to the tune of about 50k, but found this one in the meantime, as i stated its a one owner with verifiable maintance records, I had it checked out by 3 diffrent sources and all say its very healthy which I am glad for, it has 175k on it now and runs like a dream. I have a 7000k 30ft camper i tow on occasion along with a 1000k golfcart in the bed when I do, It seems to like the challenge of it and runs so much better after a good workout. I dont drive much like i said before so when i do get to work it good I try to. Its perfect for what i do, and quite honestly I picked it up for 21k I couldn't complain. I am not a "hotdog driver" nor am i trying to pretend like i am at a tractor pull either, just want the muscle when I need it. I have heard about the 6.7 valve issue along with the turbo issues, and of course got the bug to look at the new ones which i must say are beautiful. But the sticker shock hurt. I know there are good ones and bad ones out there and maybe I got lucky. Just trying to get as much info on the 6.7 before i take that leap, and of course asking the question, " do i really need it and can justify spending that kind of money". What i know about the dodges is that most everyone says they cant put a tranny behind the cummins that will hold up to it, I know nothing about the duramax. What I have to admit though is even though I was brought up in a dodge family, the fords are just beautiful, confortable and easy to drive.

Thanks to all who have responded thus far and to any one else who would like to chime in. I am all ears.

 

The 6.4L used two turbochargers in a somewhat sequential arrangement. The 6.4L engine made roughly 350HP and 650lb-ft of torque. The early 6.7L engines featured a Honeywell / Garrett GT32 sequential turbocharger making 400HP and 800lb-ft of torque. Early versions of the engine suffered some valve issues and problems with premature turbocharger failures. Newer 6.7L engines (2015+) use a single Honeywell/Garrett GT37 VGT or variable geometry turbocharger. This version of the engine makes 440HP and 860lb-ft or torque. I'm much more well versed on the later 6.7L engine than the 6.4's. I know the 6.7's sometimes had EGT problems, glow plug issues and some other things. More than likely a 6.7L engine that's running now is in pretty good order provided the maintenance has been done on it. As usual I'd recommend an OASIS report from the local Ford dealer which shows what warranty work has been done on it.

 

I had basically the same truck in a '10 F350 4x4 dually and my '13 F350 4x4 dually. The transmission is MUCH better in the 6.7 as well as fuel mileage. I tow a 16k pound camper most everywhere the truck goes and noticed a two mpg increase over the 6.4. The '13 model year and up got a little bigger brakes and the '15 and up got a better turbo, exhaust brake and more power. I had a stumbling issue with my '13 but was just remedied by a new flash. The 6.7 is just so much more refined platform that is very easy to drive anywhere, pulling anything. The only thing I wish my truck had is the exhaust brake. Extremely happy with my 6.7 over the 6.4.

 

I would step up to a 6.7 from a 6.4 any day of the week and 1000 times on Sunday. No comparison between the 2.

Only thing a 6.4 will do better than a 6.7 is pull like a freight train on the big end tuned. Even then, you still run the risk of a 1000 different ways it will leave you needing a long block replacement.

If plans are to stay stock, the 6.7 is a no brainier. There are gonna be some killer deals on 2016s coming up very soon. Or step into the 2017 and have the toughest, smartest most capable Super Duty ever.