Greetings!
I have a 2008 F250 Super Duty with the 6.4L diesel. I recently had a local shop do an upgrade to delete the egr, cat, and dpf, replace the exhaust with a new 4" stainless system, and upgraded the intake system. The shop also installed a H&S Mini Maxx tuner and downloaded what I believe to be a canned software version for the 4 modes of operation - stock, tow, street, and performance modes. Because of the the deletes, it is also running just fine in the high sulfur mode.

When I picked up the truck from the shop, they advised me to remain in stock mode when towing my 10,000 lb 5th wheel. I would have thought that a little extra power - such as tow mode - would be ideal. Does anyone have any idea why I should not use tow mode when towing a heavy load?

Thanks!

 

My understanding is they run too hot, and combined with high boost pressure equals lifted heads or stretched out head bolts


Then there are others who tow while in modes other than no power as well


I have looked up and seen all kinds of opinions on it.


I have been taking a tempered approach with my truck and mini maxx


I ran a dpf-r + for a few months with the plus 70 tune


I then switched to mini maxx, and have run a month on the HD Street tune, at plus 225, and just last night went whole hog with the HD Performance tune, and set low boost fuel to 2. If it smokes more than I want I will adjust accordingly, but sounds like I should be fine there.


My pressures and temps don't seem to be out the ordinary, but then again I'm not romping the **** out of it either.


In about a month or so I will send in for Gearhead tunes

 

the 6.4 engine cant handle being pushed to higher horse power under real work conditions. if you need real work power on a 6.4 the answer is higher rear gearing 4.11 or 4.33.

for heavy work trucks, ford actually reduces the power rating by 25hp to off set the engines inability to keep cool and low exhaust temps.


the 6.7 is a different story...more head bolts, bigger lifters, no turbo piping, etc.

if you run those fancy tunes while towing with a 6.4, your doing a crap shoot with your head gasket.

 

I run the tow tune all the time though I never tow more than a few thousand pounds, of my memory serves me 7000 pounds sticks out as the maximum for the tow tune. You would need to research.

 

I never had issues towing my 5th wheel on custom tunes at altitude or hills. I was running 4.10 gears, the BPD 1/2 kit oil cooler and quite a few other mods though. Just keep an eye on all your fluid temps.