2500 Hemi Seems Slow

[bwalker]

Howdy,

I recently bought a 2003 Ram 2500 5.7 Hemi 4x4 with 3.73 gears. Only had 60,000 miles so I replaced my 2004 Ram 1500 5.7 4x4 with 3.92 gears CAI and Flowmaster exhaust with 173,000. My issue with the new (to me) truck is that it has a hard time holding a speed even towing a small trailer empty on the highway. This wasn't much of an issue with the 1500. Another issue is my avg mpg is around 9. 60/40 city/ highway. I really don't care if I have poor mileage as long as I get more power. Wondering what improvements everyone has made that attributed most to better torque with these trucks. Any help is appreciated. Thanks much

Ben

 

[MADDOG]

Same engine + heavier truck = slower truck. You can do the three basic mods of intake, exhaust and programmer to improve things a bit. Add a custom program to that list for even better results.

Last thing that comes to mind to improve torque and low end power is going to a taller (numerically) differential gear set. So if your 2500 has 3.73:1 gears, go to 3.92:1 or 4.10:1 gears.

 

[HemiLonestar]

Same engine + heavier truck = slower truck. You can do the three basic mods of intake, exhaust and programmer to improve things a bit. Add a custom program to that list for even better results.

Last thing that comes to mind to improve torque and low end power is going to a taller (numerically) differential gear set. So if your 2500 has 3.73:1 gears, go to 3.92:1 or 4.10:1 gears.

Same engine + heavier truck + less gearing = slower truck
Dunno if anyone actually makes those ratios for that axle, next step may actually be 4.56's

Gears will make the most noticeable difference in your towing ability and giddy up; more mechanical advantage. After that, you're gonna have to up the power, and I mean crack open the engine for improvements not just a canned tune. Here's the problem with that part of the plan; beyond a comp 260 or similar (which would be a good cam for that application) you can't properly tune with an 03 PCM. If it were my 03 2500 and I didn't wanna convert the harness & PCM over, I'd regear it and throw a 260 in with a Superchips 91 tune.

 

[SavedByGrace]

Same engine + heavier truck + less gearing = slower truck
Dunno if anyone actually makes those ratios for that axle, next step may actually be 4.56's

Gears will make the most noticeable difference in your towing ability and giddy up; more mechanical advantage. After that, you're gonna have to up the power, and I mean crack open the engine for improvements not just a canned tune. Here's the problem with that part of the plan; beyond a comp 260 or similar (which would be a good cam for that application) you can't properly tune with an 03 PCM. If it were my 03 2500 and I didn't wanna convert the harness & PCM over, I'd regear it and throw a 260 in with a Superchips 91 tune.

When i was accelerating i was in 2nd on a medium incline.. couldnt get past 43mph. it was a joke - this was a 28ft boat on a triple axle.

Here - watch how pathetic it is:

2003 ram 5.7 what is wrong with this thing

Terrible mileage. No towing power. New cat, new HD TC. Reman shortblock 10k miles back. Engine was 100% in spec. Not a single issue. Verified fuel pressure, ...

www.youtube.com

 

[HemiLonestar]

When i was accelerating i was in 2nd on a medium incline.. couldnt get past 43mph. it was a joke - this was a 28ft boat on a triple axle.

Here - watch how pathetic it is:

2003 ram 5.7 what is wrong with this thing

Terrible mileage. No towing power. New cat, new HD TC. Reman shortblock 10k miles back. Engine was 100% in spec. Not a single issue. Verified fuel pressure, ...

www.youtube.com

Why would you quote something 4 yrs after the fact LMAO? Sounds like operator error to me
I don't have this problem with a 2003 1500. I towed 7000 lbs of SUV + trailer from TX to CT through the TN mountains; didn't have this issue. Granted, going up those steep uphill grades with the stock 3.92 gears I was only getting to about 45-50 mph.