mdsuperduty i will say that race wise the 5.4 is slow down low untill the 2500rpm range, but ive towed our john deer 3320 tractor with front bucket and backhoe attachment it weighed in at just about 6500lbsi believe plus the 1800lbs that our 7k utility trailer weighs. so at about 8k the 5.4 with mikes tow tune is awesome, the trucks pulls great down low has no problem staying ahead of traffic from a stop light. granted i live in new jersey where its at sealevel and no mountains so i really cant say what its like to tow that weight at crazy inclines or mountain passes. besides towing that much weight you shouldnt be worried about going 100mph in a quartermile you know.

 

i also towed my cousins new mud (1975 K30 4x4 with 12 inch lift and 44"tires and454 big block on a home built 10000lb trailer) truck last summer from upstate PA back to NJ and up some of the nice passes their the truck would drop out of OD and stay at about 4 to 4500rpm to stay with traffic at 65mph. i wasnt worried because ive read how they run good at that rpm pulling weight and i just let her rip. His truck felt WAY heavier than my backhoe and my gas gauge let me know it! but leaving a stop light or making a turn and driving the truck it didnt feel underpowered leaving and getting up to speed. again i was driving the proper way with that much weight behind me, there was no hot ******* it like i see guys with souped up diesels doing every day on the highway

 

Yea I wasn't worried about racing while towing and really never concerned with it. I just thought the truck had to work way too hard to at least remain at a good speed (50 in a 55). I'm sure my expectations were way too high and yea it did the job without a hiccup, it just dragged along at times. I defended the engine when I had it but like I said, for the minor drop in fuel economy I'll take the extra power. I mean this thing really pulls. The 5.4 no longer exists but the V10 lives on in the 650 line. But yea getting the load there safely is the first and really only concern. I'd say for local towing where speeds are not in excess of 45mph the 5.4 does a good job. Either engine works I just felt the 5.4 sounded like an angry bee hive in the higher rpms where the V10 feels and sounds different (more powerful). I agree about the diesels but my buddy has diesels and is probably the slowest tow around because he has a light foot, but that diesel moves the load with ease. Where a light footed 5.4 would probably take a while.

 

was your truck bone stock or did you have stuff done to it? yes the 5.4 has the weirdest sounding V8 i have ever heard but with a good exhaust added it sounds realgood. i never towed anything heavier than a duck boat the first year i owned my truck. after that i started adding everything and didnt tow with it till almost two years after. so by then i had everything but the gears and i was happy, but thats when i got gears and towing was allot better.

 

Yea mine was bone stock and like I said the 3.73's were a bad combo. I don't like modifying trucks much anymore and most of the stuff is just for show and sound. I posted in another thread where talk of exhaust, tuners, and intakes for improved mpgs. If you look at the true cost of the upgrades upfront vs minor improvements in mpg it could take years to pay off the upgrades before saving anything. Its like people who have a truck and then go buy a $10,000 motorcycle to save gas You just spent $10,000 and now more insurance, helmet, riding gear, more mods for the bike, etc..... I have a car that I lucked out getting for free so I acutally save money now commuting with it.

Now mods for pure performace enhancement...thats a different ball of wax.

Maybe when the warranty expires on this truck I'll think about one of the 5Star Tuners but it pulls just fine as it is and I would like to avoid the mishaps with the computer programming.

Also for all the modifications in gearing, tuners, exhaust, etc... if you purchased a new truck you could have checked the box for $600 for a stronger motor and used the extra money saved from a gear swap to make up the minor fuel mpg difference. Its all just one big pot of money in the end. Just a thought.

 

i think we got off topic now with the towing. but like mentioned earlier my truck too gets this flat spot right around 3k, like it builds power and then kinda dies at 3k for a while and then builds again? its weird

 

yea mpg wont go up after upgrades, the better power and pulling really keeps your foot on the go pedal longer. besides stock sucks! the factory settings on the tranny are just awful, if i had to driveone more mile on that jello pudding soft shift pressures i would have killed

 

Yea sorry for the off topic .

I did have that deadspot though too. Do you still have it after the tuner?

 

Did'nt mean to sound like a A.H, man but i know what you mean about the lower RPM lug i have 3.73 and 20" on my 2000 5.4 duty. Anyways hope you find a solution to you problem

 

everything ive done to my truck helped it out, mikes tunes are great but its still a 5.4 in a 4x4 super duty. whatever quirks it had stock are always going to be there, yes add on help with some and make it better but like i said there always gonna be there. its just the motor period, thats how she runs. only thing i guess you can do is either completely bore and stroke the motor, cams, intake but none of that is available for the 5.4 in the SD trucks. I was just curious to see if thats how all these 5.4 were and i got my answer, YES

 

One of my most significant memories of that deadspot was pulling out into traffic with the dump trailer, probably should have waited, and I hit the go pedal and it was pulling good and then at 3k rpms it just stopped accelerating and the all of a sudden it kicked in again. The feeling reminded me of the times when I would forget to shift out of 1st gear on that GSXR600 and the rev limited would kick in, at something like 12,500rpm!! Ha!!

 

yea i know that weird stop and then rising power again. i wonder why these motors do that? even when they are tuned?