First, I would like to say that anyone that says you can't even tell it's back there is full of it because damn the truck just rides so much smoother. The trailer weighs between 7500-8000lbs, so not a lot of weight. The whole trip we were between 63 & 65mph with the cc on in t/h mode. I sold my 1/2 ton z-71 for this so I was pretty excited to see the difference. All I can say is night and day. It is so nice not to have to worry about every little hill and just let the truck do the work. The one problem, or concern I have is one particular hill we climbed. For those of you familiar with the area, it is the 101 north about 20 miles north of Santa Barbara, just past a tunnel, and then a 2 or 3 mile hill that starts out not too steep, but towards the end it seems to steepen towards maybe 4-6 %. I took the truck out of cc and it down shifted to 4th and would not go any faster that 60. Even when I gave it full throttle nothing changed. It wouldn't even drop to 3rd. I may be out of line here, but I thought with the pulling power these trucks had, 8000lbs would be nothing at all. I only had 1000miles on it at the time, so that may be part of it. Is this normal, or is the hill steeper than I thought? Fuel mileage was only 10.4 heading there, and 10.5 heading home. Hope that gets better too. My wife thinks I expect too much. Is she right?

The engine is still not broken in at 1,000 miles. My mileage and power went up till around 5,000+ miles and then leveled off. I now have over 115k miles and MPG is the same.

Pulling my 11k pound 5th wheel, I've gotten from 10.5 to 13, depending on terrain and head wind. I typically drive around 65 to 70...speed will cause the engine to really suck the fuel.

Give it some time and the engine will come around.

Good luck and Happy Camping!!!

MaxRock

what had this truck down to 60, would have had your z71 down to 45 and you would have had about 6mpg. it will get better, but you were still giving it a workout. if you want to tow the hills with no problem at all, get a chip and stick in it. that will fix about any hill you will pull.

Jerry01, Something is wrong here if you have to ask if your wife is right! Isn't she always right? Or is that just mine? I don't remember for sure but I don't think the grade you are talking about is steeper than Cuesta grade and I can pull it faster than I would want to. Maybe it is the breakin that will fix it(hopefully).

I put husky floor liners in my 2004.5 and somethin seemed funny when i floored it. I took a closer look and the accelerator pedal arm was hitting in the mat and not going to full travel. Not sure what to do aboutit yet.--FYI

Jerry01, lots of variables affect how these trucks tow. Out of curiosity did you change tires? Towing with cruise control, while great on flat surfaces and minimal grades, likely isn't the best choice for towing long steep grades like you described. :o:

By chance were you watching your engine and tranny temps during this climb? The PCM has built-in protections for the engine and tranny and will pretty much "back er' down" when needed. You were in tow/haul mode, right? :o:

If you haven't installed an EGT gauge already it should be pretty high up on your list if you are going to tow like this. Several mentioned programmers to provide some additional umph when towing. Good idea, the additional hp/tq is welcome when towing and you'll find grades easier to climb and mpg's up a bit. There's plenty of intel on the DP about them and no lack of opinions either. An exhaust upgrade is a must with any programmer when towing, or water injection might do the trick. :grd:

Looks like you have some reading to do. Glad to see you posting on the DP forum, there are many very knowledgable people out here to gain intel from. JJ :)

I put husky floor liners in my 2004.5 and somethin seemed funny when i floored it. I took a closer look and the accelerator pedal arm was hitting in the mat and not going to full travel. Not sure what to do aboutit yet.--FYIhad the same trouble in my truck for a while, if you pull it closer toward the seat it won't do it, but it will often work its way back toward the firewall.

Thanks to all for the input. The truck is stock, as for the tires. When I started the hill, I took it out of cc, but kept it in t/h. I was watching the temps and the engine temp didn't move a bit. The tranny temp might have climbed a bit, but not much. Maybe thats what these trucks do up steep hills. I did notice that after cresting the hill, it sounded like a really loud fan turning on. Is this normal, or is it the computer doing some kind of protection thing? By the way, as far as EGT'S are concerned, if I keep my truck stock, do I still need an EGT gauge?

Jerry01,

The loud noise you heard is probably the engine fan. When it comes on it make one heck of a racket. My engine is stock, but I do have an EGT and boost gauge installed with Kennedy's 4-5" exhaust. When towing my 5er, I haven't gotten into the yellow on my EGT gauge unless I'm lugging the engine during a long climb...then it will just barely get into the yellow.

I like the gauge package so i can see what the engine is doing. Nice to have in case something starts going wrong, you can better monitor the engine and detect issues quicker.

MaxRock

[QUOTE=Jerry01] I took the truck out of cc and it down shifted to 4th and would not go any faster that 60. Even when I gave it full throttle nothing changed. It wouldn't even drop to 3rd. [QUOTE]

jerry - on my 6.0 gasser, I would "unlock"the torque converter under a super heavy load, when going uphill.... just quickly let off the go pedal, and then get right back into it. It'll unlcok the TQconv and you'll see the rpm's go up a good bit. Watch the rpm's in normal driving and you will learn when the TQ locks up... you'll approach target rpm's, then itll settle down about 300-400 rpm's. thats when it locks. Its a good tool to learn when towing. I did and it helps me a good bit.