Heavy Weight Champ

[AXE]

DEF consumption was pretty high with this kind of low mileage. I just figured out I burned about 6 gallons in 1660 miles. Pauper had posted DEF consumption was 2-3% of fuel, so at 3% and around 200 gallons of fuel burned, I think that is about right. I've never seen a burn rate that high on my previous LML Duramax, so they got it dialed up on these rigs.

Also had some wierd DEF messages flash up on the DIC. Right after I added DEF and took off, it woukd give me a low DEF message <500 miles to go before reduced power. That's the same message you get when it is actually low. Also had these annoying messages come up in DIC and I could not clear it for 60 miles until I added DEF at my next fuel stop.

Very wonky software for this DEF system....... same ol bullshit as the rest of the programming.

 

[8ball_99]

Yikes, Yeah not cool. That's actually why I ended up deleting my LML. Had a camper behind me in TN mountains late at night. Truck prompted low DEF 800 miles of range. About 5 mins later it prompted me again 500 miles range. Few mins later I got a message DEF empty, reduced power. Refill tank, speed will be limited to 35mph upon restart, lol. Turns out I wasn't out of DEF at all, the sensor just wasn't reading correctly. Once we made it to camp a buddy of mine was able to get it working the next day. With in two weeks I drove it up to KY and had the same buddy delete it. Truck had less then 20k miles on it. Never cared about the DEF stuff really, But the fact that I was almost stranded 300 miles from home with my toyhauler and a basically new truck because of a DEF sensor. Warranty or not it had to go, lol. After that experience and some of the emission problems my friends have had over the years. I just don't have a ton of faith in the systems. They do seem like they have gotten better, Still seem like the weak link on these trucks though.

 

[RCF71]

Of course, once you blow past 70 mph it gets significantly worse with heavy loads.

Wind drag is a biotch on this truck without any kind of load! Its amazing the difference in MPG I see between 65 & 75/80!

 

[AXE]

Wind drag is a biotch on this truck without any kind of load! Its amazing the difference in MPG I see between 65 & 75/80!

Yep she's not good in the wind tunnel. But it's hard to understand why the truck on the left gets -3 mpg when they look similar and run the same HP, pulling the same gear.

 

[AXE]

Yikes, Yeah not cool. That's actually why I ended up deleting my LML. Had a camper behind me in TN mountains late at night. Truck prompted low DEF 800 miles of range. About 5 mins later it prompted me again 500 miles range. Few mins later I got a message DEF empty, reduced power. Refill tank, speed will be limited to 35mph upon restart, lol. Turns out I wasn't out of DEF at all, the sensor just wasn't reading correctly. Once we made it to camp a buddy of mine was able to get it working the next day. With in two weeks I drove it up to KY and had the same buddy delete it. Truck had less then 20k miles on it. Never cared about the DEF stuff really, But the fact that I was almost stranded 300 miles from home with my toyhauler and a basically new truck because of a DEF sensor. Warranty or not it had to go, lol. After that experience and some of the emission problems my friends have had over the years. I just don't have a ton of faith in the systems. They do seem like they have gotten better, Still seem like the weak link on these trucks though.

I had a similar experience on my L.ML rolling down the interstate 75 mph and it immediately through me into limp mode and I couldn't make 15 mph.. Honestly, the only time I've ever had to pull off the road for a mechanical in my life. I was able to clear the emissions code and get down the road about 15 miles to my turkey hunting camp. It limped a second time just before camp. Cleared it again and drove 150 miles home and to the dealer. Turns out it was a DEF temperature sensor that went bad. Ambient temps weren't even close to freezing......I guess the system couldn't read ambient temps from the DIC......LOL.

If I run this back to ND next summer, I might register it there. Then drive into Canada and get it deleted. They don't have the bullshit laws. In Arizona, I have to have it smog tested after 5 years, so deleted trucks aren't the norm around here.

I actually don't mind the DPF, cause it keeps the soot off the side of my camper and boat, that shit is hard to clean off a gel coat.

 

[RCF71]

Yep she's not good in the wind tunnel. But it's hard to understand why the truck on the left gets -3 mpg when they look similar and run the same HP, pulling the same gear.

You said the other one is tuned huh? I’m sure that makes a big difference - tuned for power/efficiency vs for emissions.

 

[AXE]

You said the other one is tuned huh? I’m sure that makes a big difference - tuned for power/efficiency vs for emissions.

It had an emissions intact tune by Duramax Tuner. I don't think it did much for mileage overall, but I ran 3 different power settings (heavy tow, light tow, street) of the 5 available and they were all good. Had to be careful not to be in the wrong setting if towing or it would throw codes for air flow and turbo. Most of the time that truck ran around 475 HP which is the same as current truck. 6 speed transmission, so the power hits different and shifts were firmer.

I'm hoping they have one for the 24 soon, they said they were working on it. I'd like to see a little more power, but this rig is pretty solid performer at 475 HP. I pulled a few 6% grades at 75 mph and didn't even break 2700 rpms. Transmission always seems to be in the right gear and exhaust brake is pretty good (not Ram good, but better than before).

 

[AXE]

I got my toyhauler loaded up and went for a deer hunt. It weighs 13.5k ish when fully loaded. It towed pretty good, but cab definitely feel that extra weight when accelerating and braking.

I had my air bags at 75-90 psi. Felt better at 75 psi on some semi maintained dirt roads with some rough/washboard areas. But needed 85-90 psi on the pavement at speed to smooth it out. If you don't have bags, I don't think you'll like towing above 10k with a conventional trailer. Haven't towed a 5er so can't speak to that, but I would advise it might be better.

Out of town I was going up hill or flat most of the way and that felt petty good 65-75 mph. Coming home the downhill grades with corners felt a little squirrelly. I'm not sure if its the lightweight Goodyear tires flexing too much or what, but I thought the trailer wiggled a little and didn't feel settled in a section with uneven pavement. I thought those tires rode really good with all the other trailers. I guess I'll have to give it another go and see what it does on a longer trip. May need some heavier sidewalls like the Toyos on my previous rigs.

 

[AXE]

Here's some trailering advice from Funk FPV! LOL