All the years I've had my truck I've only done light towing (5k). Truck is mostly stock and I don't drive it daily. 104k miles, 2006 mega cab 5.9. Last year I started towing a travel trailer and I think the truck is weak towing. It's a beast empty. I'm losing speed on highway overpasses. Not grades or slopes, overpasses. I dread a trip in the mountains. So I'm wondering if I expect too much out of my truck or is this normal? My camper is a bumper pull toyhauler, around 13k gross. I added EFI Live, it helped a little but the truck is totally flat from 55-60 mph. Boosting around 28 pounds running 65 mph on flat road. Boost up to 38-40 on grades. EGT about 900 on flat road, most I've seen is 1150 on a long grade. Notice I'm not towing 75-80 mph, I run 65-67. Im not trying to pull a quarter mile at 9 seconds but I don't think this truck should be struggling as hard as it is.
I'm not exceeding any specs so what's going on? Can anyone explain your towing experience? Thanks in advance.

 

Sounds like you need more aggressive programming. EFI live is only as good as the programmer. I'd set it back to stock and try a plug in programmer. The fact you are only hitting 1150 on the pyro but are seeing over 30 psi of boost makes me think you need more fuel.

 

So why didn't you go with better truck than 06 Mega Cab, we have better option instead of this, like Ram 3500 or Ram 4000, we are using Ram 3500 as a long distance towing service in new york, the performance is great, even we towed with a heavy duty load. but it didn't disappoint us.