Initial experiences with a 5500 4x4

[ksss]

I finally have my 5500 set up and working. Here are some initial impressions

Positive: rock solid chassis. Handles fifth wheel loads very well. Great visibility, and the turning radius is also great. Great truck for a business because it looks so impressive. I tricked mine out with large decals etc. Gets a lot of looks.

Negative: I was worried about not enough power ( based on the 520/300 hp rating and unfortunately I was right. Pulling approx. 17K it really struggles. I have purchased a programmer from Pacific Performance Engineering. Should have it installed as soon as I get a install guide that is 5500 specific. I hope that I can fix the power problem. Next and equally upsetting is the fuel mileage. So far I am getting 7.5 MPG. The programmer claims 3-5 mpg increase. I guess we will see. The 7.5 mileage is pulling approximately 10K. I went on job yesterday that was approx. 120 miles round trip and I used 1/2 a 40 gal. tank. I have yet to refuel to check the mileage on that one. My 01 K3500 has more power and gets better mileage. There are a lot of rattles. The steering takes some getting used to.

If I can get the power increased and get to atleast 10 mpg I will be happy. Right now I can't say that I am all that excited about the truck. I will continue to post updates especially after I have spent some time with the programmer enhanced truck.

[HammerDown]

What did you find out on the progammer etc....

[ksss]

The programmer has helped the power issue. It has taken at least some of the turbo lag out. I have yet to check the mileage. I have not had a fair comparison yet. Or I am afraid I am still getting less than 10 mpg. I set the programmer on the first stage which is 60 hp. I intend to put gauges in the truck and then I will step it up to the next level.

[HammerDown]

Any idea why GM does not offer any other gearing in their 4 wheel drive models? I have driven one and the rpms are quite high when running 65 to 70.

[ksss]

I don't know. Running at 65 mph is about 2500 rpm which is why (I suspect) my mileage sucks. I read other guys getting mid teens with these trucks (2X4). I seem to be the only one that feels they are underpowered (gathered from other forums). Maybe mine is a dog or I am the only one who is really pulling with it. They certainly would really benefit from the 6 speed auto. At least when empty you could squeeze some mileage out of it.

[ksss]

I checked the mileage unloaded. Made a 30 mile round trip 55-65 mph and got 13.50 mpg. Loaded With a heavy weight of about 18K (trailer and equipment combined weight) with a light weight of 10K, some stop and go driving 7.5 mpg with 280 miles range on a 40 gal. tank. When I brought the truck home I got around 7 unloaded (actually it was bare back). So between the engine breaking in and the programmer that has improved. Still towing and getting 7.5 is mighty poor.

[William Lee Gingerich]

Give it some time the duramax is barely broke in at 10000 miles. Just my 2cts

[bounty hunter]

I know what you mean about a little slugish on power. Just picked up a 4500 4x4. I pull a 42ft gooseneck trailer. Put the same programmer with snow performance water/methanol kit on it and it has ALOT more power now. But I also really hate cruising at almost 3000rpm at 75-80mph!