I've noticed since I bought my 02 Duramax back in July that it just don't pull all that great. I don't tow very often so it wasn't that much of an issue to me. But I just want to know if its just the nature of a diesel. About all that I haul is a trailer load of ATV's, and I think that my 5.3 I had before did just as well. Could their be a problem somewhere? Maybe change the fuel filter? Its only got 20,500 miles on it. Should I be holding on to my hat with all that power, or do they feel that much doggier when pulling?

my power stock is pretty good, you will loose a little with the larger tires especially while towing. check all filters for restriction. if you have not changed fuel filters you are almost 2 changes behind, start there first. if you still feel you should have more, consider adding a mild power adder like the juice or predator. also check the air filter

Most would suggest changing the fuel filter as well as changing the transmission filter. I noticed that mine shifted better once that was done. Might want to check into that. Did mine and it only had 18K on it.

I would change filters for sure. When mine was 100% stock I pulled our 3 horse trailer with horses from Bellingham WA to Billings MT over all 5 mountain passes at the speed limit plus 5 mph, no problem! Lot's more power with the Duramax than with my one ton dually with a 454 gasser!

Change the filters! Mine pulls my boat so hard it is scarry! My truck has 150,000 miles on it!

):h

Ok, I'll change filters and see what happens their. The previous owner may not have done that. Hopefully thats the problem, thanks.

Most likely fuel filter. I change mine every 4-7K and can tell when it is clogged.

Kurt-

You should definatly notice a difference in power between the 5.3 and the duramax. My brother drives a 03 chev 5.3 super chip and exhaust and he can't even begin to tow with me or keep up on the hills. My truck is bone stock except for exhaust. It might be something as simple as a fuel filter, I know my sure doesn't run to well when it's plugged.:) You should be able to yank those quads around with out even knowing they are there. Good luck!!

J-HEFF

By running 38" tires instead of stock 245's you are effectively changing your axle ratio from a 373 to aprox. 299. You should notice a big diff in your towing power.
Dave

The 38's are on my 95, I run 285's on the Duramax. Even just tonight I pulled an 18' trailer with two ATV's on it and pulled hard. Haven't got a chance yet to put on a new fuel filter yet but I'll definatley try it yet.

Kurt-

Just to let you know I run the 285's also, and it looks like our rigs are the same size, and the same year. I'm very impressed with my power, even with the somewhat larger 285's. I'm thinking that fuel filter will give ya a little better performance. later-
J-HEFF

Mine towed like absolute sh*t with BFG 285 AT's so I went back to 265's. Then again my trailer weighs 15,300 lbs.

I had the same problem going from an 03 6.0L 2500HD CC to an 03 2500HD D/A. It seemed like the DMAX didn't want to pull the load fast at speed. 60 to 65 MPH max(6800lbs) on the hills. I changed the fuel filter and it gave me just a little more on top. The truck always grunted the load perfect from a dead stop. Then I followed many people's advice, and added the juice with attitude. WOW! WOW! WOW! Just in level 2 for towing the thing wanted to tear my trailer in half! Now I'm very satisfied!

I've always been pleased with how my truck tows our moderately heavy (10k) travel trailer, but wanted to bump performance a tad to deal with those situations where stock is just not quite enough to get over the hill w/o a downshift. I added the Juice (already had gauges). Huge difference, even in level 1. Everything I had hoped for and more. My EGTs are actually a bit lower, believe it or not, and my fuel mileage went up slightly.

TC

Change the filters and don't baby the truck. The trans needs to adapt to loads where more throttle is applied like towing a load. It take several miles to get the shift pattern to adapt to a load. If you baby the throttle from the start it will shift to 2nd gear real quick and the pulling power is not there. This truck runs much better and performs over all better if you a little heavy footed occassionally. The trans takes something like 5 cycles to readjust the shift pattern to a heavy throttle vs babying the truck. Someone once said "drive it like you stole it."

Tom

I'm leaning torward filter also, but wouldnt hurt to check and make sure your trailer brake isnt stuck or sticking...
Jason

If it has brakes....

I'm leaning torward filter also, but wouldnt hurt to check and make sure your trailer brake isnt stuck or sticking...
Jason
Funny you mention the brakes, I was pulling a rental trailer with surge brakes last year and the brakes got stuck. I started giving it more pedal until the back end was hopping and the smoke was rolling off of the tires. Had to look pretty impressive as I was trying to pull into the gas station, some of the other drivers were giving me the thumbs up. Finally snapped the surge brake loose and about jerked the hitch off the truck.

I would change filters for sure. When mine was 100% stock I pulled our 3 horse trailer with horses from Bellingham WA to Billings MT over all 5 mountain passes at the speed limit plus 5 mph, no problem! Lot's more power with the Duramax than with my one ton dually with a 454 gasser!
Same here, My stock Duramax will pull my 5th wheel trailer (12,000)Lb better then my 1 ton 454 gas truck ever did. Change your fuel filter 1st.
Rich.

mine rips when pulling 9000 pounds....however fast you want to go...uphill or not

My duramax was a gutless wonder when I bought it. The old 93 Dodge/cummins would out pull it. The problem was a bad ECM (computer). The turbo waste gate was being held open. No Boost.... Much better now...:)

Since I have been working late I haven't had a chance to get to the dealer to pick up a filter. I'll get one Friday and let you all know if that was the prob. What is a good price for a filter? Do most of you get them at the dealer? I stopped at a Auto Zone the other day and was surprised they didn't stock them. Since it was out of my way I didn't order one. They were $35 at AZ, and I seen one on Ebay for about $32 for an ACdelco. And when changing them is their anything special I need to do? Just twist off and twist on?

Napa for about $12. Gotta love the military discount. Parts and filters are at cost, fluids at 10% off.:ro)

Talk to Eric (dmaxallitech) or go to
http://www.gmdieseltech.com/
He should have the NEW GM filters that are supposed to be better than the first version.
Jason

Comparing my 03 D/A to my 97 454, the more weight, the bigger the difference. Light loads, the gasser made enough power to hang, but when I start towing heavy, 7000lb and up, the 454 couldn't come close. Most noticable on hills. Light loads don't take the power or grunt to move like heavy loads. Just a thought. Then, maybe this whole thought is a load.

Finally got the filter changed, had a hard time finding a wrench to fit it. Just drove it up and down the road and it does feel a bit snappier. I'll have to wait til I hook a trailer up to it. Could a dirty filter also be a cause of a drop in fuel mileage?

filter can account for lost mileage. run an additive for best results

Hope the new filter solves your problem. Like most here, the difference between my old 454 and the Dmax is just unreal. The 454 was constantly hunting between OD and 3rd to the point I didn't even bother running in OD when pulling my 6500 lb trailer. So far the Dmax has only downshifted twice out of OD on really long, steep hills and has never slowed down.

If you are comparing a half ton to an HD 3/4 ton, with a very light load like you are talking, you may not have much of an issue. Diesels are torque monsters but gas engines are snappy in lighter configurations. Can't quite get a complete picture from what you said. Maybe help us with this info for each truck:
Tire size
Model series
Engine
Transmission
Any Mods

RJ