Just got back from a trip from Albuquerque to Moab, Utah and back pulling our toy-hauler 5th wheel. Loaded up it weighs about 14k lbs...so no light weight for sure. I was really happy that I switched to a dually for this trailer, as it handled the weight a lot better than our 2500 HD.

A few things to note that I found interesting. 1. MPG's were really about what I thought they would be considering the truck is still pretty much a virgin. We left with about 1200 miles on the clock. Avg fuel economy driving 65-70 MPH was 9.5 with a best of 10.5. That's about what my LB7 got...so no disappointment there. 2. For anyone that says you don't need to worry about gauges with the 40hp setting on the predator and towing heavy...think again. I had to back out of the throttle to avoid going over 1300 degrees egt on several occaisions in 5th gear going up grades of about 3-4% and still had to watch it on grades of 6-8% in 4th gear. The truck has PLENTY of power in reserve, but keeping the egt's in check is a problem. 3. I found after driving at various speeds that 70mph is the sweet spot for my truck for both power and economy. I found that at 55-60 it bogged too quickly on longer grades, but at 70, I was able to maintain momentum up hills and kept the boost level up and the egt's down. 4. The turbo on the LLY sounds a lot different at higher boost levels than the LB7. It sounds like a super charger more than a turbo charger. Finally my truck ran reasonably cool. It never went over the 210 mark even up a long 7% grade at 2800-3000 RPM. Will have to see if there is a marked difference this summer.

All in all I am really happy with the performance and economy for such a "young" truck. :ro) Hoping it will only get better as the miles rack up.

Bartman, should I be concerned about EGT with a totally stock 2004 LLY motor pulling a 10,000 lb. trailer. I push the hills pretty hard when crossing the coastal and Cascade mountain ranges here in Oregon. It never really concerned me about EGT because I keep it all stock, but since I do push it at times while crossing these hills I am beginning to wonder. Any comment would be greatly appreciated.

Bartman,

What was the outside temp?

last year over the hot(80) summer pulling a 10k trailer, i did a test over the salmo pass, this is the biggest pass in canada, like a 12k up to 12 percent at the top type pass, i went to my stock lb7 tune, at the bottom, and set the cruise to 70 mph, there was times that i was under 50mph on wot, and i never backed out of it once all the way up, i seen egt from 1250 to 1300 all the time, the last mile was the highest egt of 1333 on my hoots installed probe, and this must be considered safe from gm, and the intake /exhaust mods would of keep the temps a bit lower as well

Bartman I was in Moab this weekend as well . I left on Sat. night about 10 and the snow was crazy!!! It took me 12 hrs to get home to Phoenix. Lots of people sliding off the road. Including a really nice Black lifted LB7. Poor guy!!! First tow with my truck and I loved it.

"Bartman, should I be concerned about EGT with a totally stock 2004 LLY motor pulling a 10,000 lb. trailer." :confused:

One should always be concerned about EGT's when towing! Stock or chipped, doesn't matter, at high boost the EGT's go up very quickly in these trucks. The harder/longer you push them the higher the EGT's are going to go up. As fredw attest, on long grades you can easily see 1200+* EGT's for extended periods, this is when the most damage can be done if you are not careful and backdown when needed. This is why anyone that tows with their trucks should have EGT gauges at a minimum. Without them you just don't know where you are at! :o:

Plenty of good intel on the DP site about towing with programmers and exhaust benefits. Stock air intake is fine, so put your money where it counts. My .02 cents worth. Later. JJ :)

Please explain just what an "egt" is.

I went from Phoenix to Santa Fe and back this weekend. New 5" Summitt turbo downpipe-back and Predator with tow tune. I had furniture in the Desert Fox rather than toys for this trip, and had no fresh/black/grey water, so around 9500#. Towed well, easily maintaining 75-80 mph, with lowest of 68 climbing Mingus Mtn. south out of Camp Verde.

I have all the miles (GPS verified) and gallons logged, but have yet to total them all up. However, several spot checks put the MPG around 8.5.

That 5" exhaust is interesting. Not real obnoxious inside, but the at-idle sound outside is like a small APU mixed with the ringing sound of a finger going around a crystal goblet, especially at cold high idle. As soon as the VVT come just off idle, it sounds great with just an nice low rumble.

short for exhaust gas temperture


Please explain just what an "egt" is.

Hey Bartman, is your kitty still there or not and have you blocked the EGR?

Oilbrnr, did you weld the Summit pipes together or just clamp them? Also, is your Desert Fox a 5ver? 8.5mpg at 78-80 tain't bad in my book. JJ :)

JJ: Clamp'd them. Fit better than I thought it would.

The DF is a TT, and pretty tall. http://www.nashtraveltrailers.com/28ks.htm

Ok, From Phx. to Flag to Santa Fe and back to Flagstaff was 997.3 miles, and I used 128.198 gallons. = 7.779 mpg. :eek: :( -:t

Sorry for taking so long to respond to some of you guys ?'s. No time at work to surf the net:(

Outside temps ranged from 45-70. Not real warm. Like I said, the true test will come this summer in the 90+ heat here in NM and southern CO.

I have no kitty, but the egr is not blocked...yet.

I would always be concerned about EGT's, especially when towing heavy. Short bursts of high temps are OK, but long, sustained temps will do damage I'm sure. I only let it get to 1400 one time, and that was for about 5 seconds max. On average, the egt's stayed in the 900-1100 range most of the trip when cruising, and around 1200-1300 for the longer climbs. Unfortunately, Eastern Utah, Southern Colorado and Northern New Mexico are NOT flat. Lots of rollers with some long sustained climbs with healthy grades! I recall that 1300 degrees in the max you want to sustain for any period of time.

The exhaust is not silver anymore:eek: Amazing what some heat will do to stainless. Oh well.

I would like to try a Van Aken for the LLY to see if there is a big difference in EGT's, but mama aint gonna go for that right now):h

Hmm, well I didn't hole a piston. I'm holding out for Brakesmart to get their boost/temp module out, as I don't have any big desire to go down the whole A-pillar scene. Had it b4 and would prefer to keep this one a bit more on the DL.

She runs better now then when I left on the trip, so I'm not going to loose any sleep. Interesting info though and I'm surprised that Diablo would map enough fuel to exceed 1300* with a decent exhaust for their tow tune, regardless of the gross.

I wouldn't think there is a problem with the pyro (autometer). I was a bit shocked how quickly the egts got to 1300, but that's what it showed. I would like to know if anyone else using the predator notices the same thing. I think it would take some pretty intense heat for a long period of time to burn a piston, but I'm not willing to try:eek: . I know some of the big boxes are putting the egt's over 1600, but for a very short period of time. Seems like I recall John Kennedy saying that he has gone over 1700 in one of the pull-offs. THAT'S HOT:devilfing