Hello forum, this has happened three times to our truck, the first time was an empty 2 axle 3500lb trailer. I was pulling this trailer for about 100miles and after I unhooked it felt as if it had alot more power, but thought nothing of it and maybe the perception change of no load vs load made the truck feel to me as if it was faster.

Then we picked up a 4000lb car and towed that about 30 miles, and after unhooking the same thing, it felt like it had more power. So conducting a little test Powerbraked the truck and sure enough it spun all four rear tires. Fastforward to today I took 5500lbs of scrap forklift to the scrap yard and after unhooking, same deal spun all four rears but for a longer distance than last time.

Now if I try to do this without previously towing, the truck does not spin the tires at all, so does that mean the ECM on 3rd gens changes the fuel settings when you tow? And it takes a few miles for it figure out that the truck is not towing anything and will go back to stock?

 

I'm prolly just as crazy as you are, but I noticed the same thing in my truck, not a 3rd gen but it seemed faster, I did try to take into account of the truck being unloaded, didn't try the power brake thing though.

 

All diesels are like this. It cleans the injectors. Like in the old days, when you were told to "blow the cobs out of it".
Don't loaf theses diesels around, keep them cleaned out.

 

I've noticed with mine that fuel milage will slowly degrade if I run short trips empty all the time, but milage will get better after a good tow.

I figured it was burning off carbon and cleaning out injectors...

 

But it goes back to normal after 8 miles or so. If it cleans the carbon off which gives it better power, then using biodiesel should clean everything up. I thought that since the truck only has 15000miles on it it shouldnt have that problem but I guess it does.

 

Yeah, it's like an Italian tune up.

MikeyB

 

I, too, noticed the same thing after making a 605 mile round-trip run to SC last Saturday. Traveling thru the hilly areas of I-40 & I-26 with a neat little 1966 Ford F-100 2wd truck on an 18 ft car hauler contributed to getting the cobwebs out of mine.
Greg

 

I think you guys are all on drugs!!!!! I tow with mine daily and hard towing at that and I can't spin the tires to save my life!! I can only spin em on gravel or sand no dry roasters here. That being said........ I was told by several people who own(ed) dodges that "the best thing I can do it hook a huge trailer behind it and tow like wild for a while" to help break in the engine and get better mileage. I was told by the dealer to "be nice" for the first 500 miles and absolutley NO TOWING OF ANY KIND for 500 miles. Then all bets were off. I told them that I tow for a living and monday morning it will be hooked up and probably never unhooked. They responded with drive it as much as possible over the weekend!

 

Our truck is almost a year old and 15,000 miles, that would have something to with it? Just recently for the past few months we have been towing with it but before that the occasional 1000-2500lb load of weights, tires, walnut trees, misc equipment and etc.

 

That 500mile headroom is not for the engine, but for the gears, tranny, and tc if so equipped. When you get gears installed, they tell you the same thing, you have to work harden them before loading them too much.

 

This is funny because i have been meaning to make a thread on this same question. i too notice i have more power after unhooking from a good tow. i never have tried the power brakeing but with my SO you can tell when any type of extra power appears... these SO trucks are dogs compared to the newer ones!

 

I think you guys are on drugs also. The SOP feeling you get is because there is not trailer behind you weighing things down. My work trailer is on my truck all week. Sure it seems faster on the weekend, but the trailer is off then. What I do notice is that my mileage really picks up with the warm weather. Was almost 90 here a few days ago and the fuel gauge hardly moved. Yesterday and today have been f___ing cold; 46 degrees for a high today. Anyhow, the fuel gauge is moving a lot faster yesterday and today. Just my .02.

 

Its not only the "feel" of more power but the fact that the dually cannot break its tires loose to save its life before towing compared to spinning them a good 50-80 feet after a good tow. On mechanical pump engines like the 1st gen 1989-1998 models wouldnt be able to do this because if computer setting is at play here, they wouldnt apply. 98.5+ might do this but since cummins changes the engine to common rail and a bunch of other things I dont know it could have also changed the computer to add a few here, change settings if engine got too hot, defueling, etc.

I have heard that on some semi trucks, class 8 trucks have engines where when they hit a hill, and they need more power the engine automatically adds a bit more power to pull the hill, then after that it comes back to standard settings. Also they are able to shut down the engine if any level, temp, rpm got too high or defuel or depower the engine b/c most likely non owner operators dont care 2 cents about the truck they drive and usually give it hell.

 

When I was a farm boy, we would mow with the diesel tractors all summer, then when it came time to plow ,the tractor would labor with it for about 4 hrs.
After that they ran great. It was not the plow shares shining up either , they were greased after last years work.

Diesels are not for light throttle work. Pull them they will thank you for it by lasting longer.

 

I too felt this power, but lileage as well. I have 50K miles on mine. Before a good tow a month ago, i gould meagre up 14-15 USMPG. But after towing 18K behind me, I got 14 with the trailer on, and now i can get 17-20 USMPG.

BTW, My dealer told me that if the truck is empty, drive it like you stole it. Dont accelerate like a little old women, let the engine hit 2500 before it shifts, and the engine will reward you with the slightly better mileage, getting there a little faster, but lasting 100K longer.