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Speed and MPG

As well as tire composition, wheel/tire combo weight.
I dont think those are as much of a factor when we are towing heavy as on an economy car but I am sure theybdo effect mpg in everything.
 
I'll play.

03 GMC Sierra 2500HD.
LB7. New nozzle style injectors, EFILive 5 tune. No lift, 265 75's

Unload, at peak torque . 20 mpg

Towing the Yota-toter ( 25 foot, 14k gooseneck with a Lance and my rig on the back, total Cat scales at 19.9k ) to Hammers on the flats, zero headwind = 12 mpg. Peak torque equates between 65 to 68.
Headwind drops me to 10.
If I jump up to 70, lose one mpg.
But. With a tailwind its on.
I've seen 14 at 70 mph.
Those are good hauls :)
I really like the early GMC for the rounded nose.


Very aerodynamic.
With the 10 speed, running at peak torque (1600 rpm) is a bit fast for optimal mileage.
 
I'm just throwing this out there for the sake of information and comparison. I agree that mpg for a given amount of work being done doesn't seem to have changed much over the years,
Thermal efficiency of the fuel is thermal efficiency of the fuel.
Piston engines can only be so efficient.
We are at a technological point that we are squeezing the last few little hidden bits of efficiency out of both gassers and diesel, but its still a game of diminishing returns and overly complex and unreliable components.

Also a great example of how special interests and government has stifled technological advancement and created a false market full of not free market capitalism, but rather back stabbing capitalism, where the fittest isn't the one with the best ideas, but rather who can grease the most palms and talk the slickest.

But yeah. Now we have overly complex dinosaur piston engines with epa mandated crap and overly complex and expensive components. But hey, our rich fucks are going to space.

So....yeah.


:homer:
 
With the 10 speed, running at peak torque (1600 rpm) is a bit fast for optimal mileage.
Would love to swap the 10 speed into my 03.
I have tons of power, an aerodynamic body style but adding 6 more gears would make the truck " perfect " in my mind.
 
Just completed a 500 mile rt with my 35k motor home pulling 3k lbs

Slowing from 76 mph on cruise to 70 mpg on cruise is worth 1mpg in my setup :laughing:
 
2000rpm seems to be the point of no return for any of my diesels.

2k is give or take 70mph.
 
Just completed a 500 mile rt with my 35k motor home pulling 3k lbs

Slowing from 76 mph on cruise to 70 mpg on cruise is worth 1mpg in my setup :laughing:
but if that 1mpg is from 3mpg to 4mpg thats a hell of an improvement.

i had a dodge 440 powered american clipper mh and i would have killed for an extra mpg!



i'm really curious who can report on the difference in mpg from different tires. i run a gas '10 f350 allot of miles with a travel trailer and have an itch to try out some commercial type tires. not even sure what i'd go with, just thinking...
 
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but if that 1mpg is from 3mpg to 4mpg thats a hell of an improvement.

i had a dodge 440 powered american clipper mh and i would have killed for an extra mpg!



i'm really curious who can report on the difference in mpg from different tires. i run a gas '10 f350 allot of miles with a travel trailer and have an itch to try out some commercial type tires. not even sure what i'd go with, just thinking...

More like 6 mpg to 7 mpg...:)
 
ehhh, I'd rather be puttering along in the slow lane for a couple extra hours than paying the road pirates their tolls
everything is a race for the guys i go on trips with, there is no hope braking out of the 6.xx mpg with whats getting dragged down the road, and pedle to the floor. the 450 with 6.7 just barely gets better the the 5.4 hauling ass, 5.4's pulling maybe half the weight? the air drag is a bitch. we were hitting 90mph in places.

the 6.7 is deleted and tuned, he has to watch oil temps more than anything, and he hits the passes so fast the turbo gets hot enough the truck shuts off the engine braking on the down hill side. cant talk him into taking it easy, i think his goal is to blow it up.


this is the last trip. and we barely fit it all in 2 rigs. mines the white truckc, i dont have platinum450/ mega mansion toy hauler money:shaking: but i'm happy to have a nice shower and place to stay. my camper is less than half that size and 1/5 the cost

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when i'm with the fam. i like to take it a bit slower. i can divide the people i travel with in to two categories...

1- the vaction starts when we leave home- most family trips
or
2- the vacation starts when we get there- most guys trips


we joke about putting rubber on and running bumper to bumper down the road
 
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Point for data. My RV, 6.4 F450. Has so much frontal area I rarely see less than 12 psi on flat ground at 65 mph.

9.75-9.5 at 68-70. All the time
 
Point for data. My RV, 6.4 F450. Has so much frontal area I rarely see less than 12 psi on flat ground at 65 mph.

9.75-9.5 at 68-70. All the time

what are you weighing in at?

9.5-9.75 mpg?


i just text f450 monster trailer buddy, he said 20psi, maybe a little less, at 65-70mph
 
what are you weighing in at?

9.5-9.75 mpg?


i just text f450 monster trailer buddy, he said 20psi, maybe a little less, at 65-70mph
14500 ish. But I'm 8' wide and 11'10 tall 😂😂😂 like I said 12 min psi on fat ground. I struggle to keep under 45 on hills
 
Way to leave us 7.4/8.1 out of this thread. :flipoff2::laughing:

Mpg vary, not because of load but stop and go. On my dime, I'd cruise a bit more on my time.

On someone else dime, it's how fast they want me get there, single digit mpg without a blink.
 
14500 ish. But I'm 8' wide and 11'10 tall 😂😂😂 like I said 12 min psi on fat ground. I struggle to keep under 45 on hills

i can imagine. i'm not sure how tall our toyhauler trailers are. i know mines slightly over 8'6" wide. like you, we travel 2 and 90 allot. we do hwy 20 on labor day and its brutal, i think this year i'm going to try 4low in my poor truck. i've seen his rig hit 245* oil temp going up 90

i've actually seen your rig right by my place. you know the little campground on the other side of the highway at Deception Pass State park? i live just above there. i was sitting at the light there, seen your rig driving past. that was the back when i followed the build on the other place. i thought it was cool the wife thought i was weird:lmao:
 
Way to leave us 7.4/8.1 out of this thread. :flipoff2::laughing:

Mpg vary, not because of load but stop and go. On my dime, I'd cruise a bit more on my time.

On someone else dime, it's how fast they want me get there, single digit mpg without a blink.

wait you get out of the single digits? whats that like?

i had a 460 truck awhile back, no matter what i did, empty, loaded, towing... whatever it was always 6.xx mpg. i tried to get better. once i realized i couldn't i said eff it and just hammered on it. probably why i remember having so much fun with that truck. a buddy wrecked his truck and sold me the rims/tires cheap it was fun, but sold it before i wore the tires out wasn't about to drop that kinda money on it!


WP_20140424_002.jpg
 
i can imagine. i'm not sure how tall our toyhauler trailers are. i know mines slightly over 8'6" wide. like you, we travel 2 and 90 allot. we do hwy 20 on labor day and its brutal, i think this year i'm going to try 4low in my poor truck. i've seen his rig hit 245* oil temp going up 90

i've actually seen your rig right by my place. you know the little campground on the other side of the highway at Deception Pass State park? i live just above there. i was sitting at the light there, seen your rig driving past. that was the back when i followed the build on the other place. i thought it was cool the wife thought i was weird:lmao:
Haha small world! We do deception a bit. My old dog loved it there.

Hwy 20 is brutal. I generally just hit 230 ish by the time I am past liberty bell going west bound. Travel 90 and 2 weekly it seems! 2 is steeper eastbound. Have to slow a bit. Try to stay under 40 and psi/1100 egg ish
 
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