the1adman wrote:
We have a 2003 Dodge Ram 2500 quad cab 4x4 Hemi automatic 3.73. The truck only has 58k miles and well maintained but towing 5500 lbs the truck struggles, on hills it's in 2nd gear and on long steep hills will shift between 1st and 2nd and be down to 35 mph.. I am looking for advice on how to improve the towing performance. I am not looking for buy a diesel truck advice as I had a diesel and much larger trailer but down sized because of economy. I am not usually a fan of programmers or performance chips but do want better towing results. Any advice appreciated.
A few questions for you. First - how sure are you the trailer is 5500? Could it possibly be heavier? Second - did it at one time tow better? Third - how aggressive is the tread on your tires?
Obviously if the trailer is heavier, that is part of the problem. Another, which has been identified, is that by going to a larger diameter tire, you have effectively gone to a higher final drive ratio (numerically smaller), which will hurt towing performance. If you have an aggressive tread pattern such as a Mud Terrain, that will also hinder towing performance as they have a higher rolling resistance.
If it towed better at one time, have you changed the spark plugs recently and cleaned the throttle body? Plugs should be changed at 30,000. I started to notice a decrease in performance starting around 55,000 miles. I cleaned the throttle body at 59,000 and it made a big improvement.
The other thing is you have to be willing to let the Hemi rev. It makes max torque at 4200 and max horsepower at 5400. I find that on grades (I am also in AZ) it pulls really strong between 4200 and 4800 RPMs. When it downshifts, don't be afraid to manually shift to hold it in 2nd or 1st if necessary and then use the throttle to control the RPMs so they don't go to high and let the speed be what it is. The PCM won't let you over rev the engine for damage (about 5900-6000 RPMs), but once above 4800, the torque will start to fall off.
The next thing is don't be afraid to hold it to the floor when necessary. This isn't like the old carburetor engines, where holding the peddle to the floor could dump in too much fuel. With the 5.7L the throttle only tells the PCM what you want to do. If it isn't to the floor, the PCM will not tell the Hemi to give everything.
My Power Wagon is heavier than a standard 2500 and my fifth wheel is heavier than 5500, but it gets the job done.... but, I do have 4.56 gears. :) If everything is mechanically sound, gears will be the best bang for the buck. They give the Hemi what it loves - RPMs!!!
Good Luck!
