37 replies to this topic

[Vic Harder]

both my 2500 hd 8.1L gas and 3500 lbz duramax have 3.73 axles and Allison trannys.  10 mpg gas, 20 mpg diesel, 75 mph w loaded camper.

[Leviticus907]

both my 2500 hd 8.1L gas and 3500 lbz duramax have 3.73 axles and Allison trannys.  10 mpg gas, 20 mpg diesel, 75 mph w loaded camper.

Have you done any significant modifications to your LBZ? Oversize tires? Delete EGR?

[ntsqd]

13 - ~20 depending on conditions with a 6BT, 3.73's, & 315's. If I run it at the throttle setting that is 1750 rpm (well known sweet spot for these engines) on flat land we get the best fuel economy. That is to say that I maintain the throttle setting and let the engine & trans do whatever they need to do w/o varying the throttle. One 18.9 mpg leg was over The Grapevine, South to North, with that throttle setting.

 

About to embark on an expensive experiment, adding a GV OD to get a compound OD for higher speed super-slab runs. Curious to see if engine rpm or vehicle speed is the bigger mpg reduction.

[Vic Harder]

Have you done any significant modifications to your LBZ? Oversize tires? Delete EGR?

egt delete, 5' exhaust, 50 hp tow tune.  Tires are 265/75-16, so just slightly over sized. Ran same tires on the 8.1L which was also extensively tuned (25% less fuel at cruise w camper on it!).  

 

I chose the 2006 LBZ for the lack of emissions, fuel economy and reliability.  Plus I love Allison transmissions.  

[Leviticus907]

I just read up on the GV OD. That sounds like quite the transmission enhancement! More focused towards older 3 and 4 speed transmissions? To double the gearing? I didn't read much, correct me if I'm wrong. And I'm going to guess that it's vehicle speed is the greatest mpg reducer due to wind drag. Let us know how it goes!

[ntsqd]

I wouldn't be doing it if I hadn't found one used for significantly less than retail. Will need to adapt it to our truck's transfer case or change the transfer case to what it is set-up to work with. Even with that investment I'm well under retail. Will post the results when I have some.

[Leviticus907]

Well just a little update, I purchased a 2008 gmc sierra duramax. Hopefully it arrives before I leave for work. If not I'll post s pic when I get back! Happy camping everyone!

[ccorbridge]

2017 F350 Dually diesel.....48 gal on board tank with 10 additional gal attached to back porch.  Plenty of range....plenty of power....only problem is the payment but that will pass.

Looks like the cab over part is very close to the cabs top. Does it touch when going over rough terrain?

[HughDog]

I like frugal - But think that a hedge could be appropriate when it comes to toys ...

If there is any chance you may switch up your game, you probably will. So - I vote getting something you can grow into even if it is way oversized (Kinda like buying a ski jacket for a child). Hedge approach obviously excludes the folks that are terrain specific and identify the need to "wheel" and squeeze through small spaces.

But lets say for example that an enthusiast dreamer may love everything "pop-up" . . . then, hopefully so does the spouse:) - One day, you may find out a 35' 5th wheel has secretly been coveted! Just say'! I'm sure this happens all the time- haha

At any rate, cant go wrong w/big'ol diesel with lots of power, payload, decent fuel efficiency, big tank and so on - AND - For whatever reason, the big'ol payment for a diesel rig is somewhat subsidized if your looking at current resale values - Probably an entirely different topic, but still relevant.

All that said - I'd love a Taco in the collection too!

Edited by HughDog, 08 August 2019 - 06:37 PM.

[klahanie]

I like frugal ...

...At any rate, cant go wrong w/big'ol diesel with lots of power, payload, decent fuel efficiency, big tank and so on ...

 

 

Hmm, much as I like both, I've not found diesel and frugal going together for me

 

One fly in the ointment could be possible breakdowns and cost of repairs. These modern diesels are complex.

 

Two examples, prob not fair but here goes ... at ~65k mikes our DPF was pretty much all filled up and cleaning almost continuously. If it doesn't clean it can go in limp mode We were on a road trip days from home but were lucky to limp to a dealer and have it dealt with.

 

Two years latter, another road trip, literally just got to our destination and the PCM failed. No crank, 60 miles in. Managed to jump the starter solenoid and drive slowly out overnight, straight to a dealer and lucky again, have it dealt with. Nevermind the cost, we are thankful both situations weren't worse - and we do know what worse can be, so no complaints.

 

Like I said, maybe not fair but the OP did mention going deep into the woods. If there is a difference in complexity and potential critical failures between the two engine packages, and I think there might be, it's worth considering them and how they might impact the owner in certain applications.