See those trucks

[02 WS6 TA]

Yep. 5.3 V8, 4L60e, 3.73 gears, 4wd

What year Durango?

My 6 liter SSS gets around 14.7 unloaded with a stall and 4:10s, pulling is 10.6-11.0 depending on my foot. Cruise is your enemy, the trans tries to kill itself on a hill. Overall, they get shi&&y mileage, but I love my truck.

[5.0THIS]

Maybe 2wd or 3.42/3.23 gears. No way with 3.73.

No. Your numbers are low across the board any way you cut it, especially highway. My truck is a regular cab short bed, so a bit less weight, but I run the 20 inch wheels and wide 275 tires as well, so... I got 17+ going across Kansas in my truck, with the cruise set on 81-82mph. 373 gears. 100 or so pounds of cargo onboard. 4wd as well.


I can do a lot better at lower highway speeds (65-70). Most 5.3 trucks from the four speed era get better than 14-15 on the highway. Maybe run some of the green GM top end cleaner through there

[Firebirdjones]

Attachment 26360

Towed this load 3 hours up north for a vacation.
Truck is 2001 Silverado 1/2 ton 4x4 5.3l V8
Boat is 1993 Rinker Captiva 206 20.5"
I got 8.4 mpg towing 60% throttle most of the way. Trans rarely shifted to overdrive, it stayed in 3rd. Transmission temps were 185 to 195*F.
I now have an onboard compressor an in-cab controls/psi gauge for the rear load leveler airbags. Ran those at 70psi.
Worth every penny for a wonderful vacation!!

Damn that's a pretty thirsty truck for a little engine.

My old 79 1 ton with a 454 does better than that. I pulled my 28 foot enclosed trailer (5,000 lbs. empty) loaded with a 4,000 lbs car, tools, go-cart, air compressor, generator etc... Across country with various terrain and never got less than 10 mpg.
Just an old smog 454 with a 400 turbo and 3.73 gears. I cruised about 65 mph for most of that 2,000 mile trip.

Around town the truck empty will do 12 mpg and I got 14 mpg highway consistently on another trip across country with just the truck-empty.

Edit: Some other interesting tidbits.

My father has 2 newer trucks, both with the 6.0. He has an 02 3/4 ton and he just went out and bought a 2015 3/4 ton. The older 02 always seemed to get about 13 mpg with mixed driving no matter how he drove it, a 4L80E with 4.10's. Towing a simple flat bed trailer with a 4,000 lbs. car it would drop to about 10-11 mpg. Not really any better than my old 454 truck, and on a tow trip we did together, I would flat run away from him on any slight highway grade while I was also pulling a flat bed with a 4,000 lbs. car. For him to keep up he had to increase a lot of throttle angle and cause the trans to downshift any time we hit slight grades. I think that killed his mileage. If he maintained throttle angle to keep the trans from downshifting, he would slow about 5-10 mph on the grades, then I had to slow down so he could catch up.
His new 2015, he just finished a 6 hour highway trip with this one, a 6L80E with 4.10's. Empty truck, he got 15.24 on the first fillup and 15.8 on the way back cruising between 70-75 mph. So it's not too terrible. We'll have to see how it does towing.

[Firebirdjones]

My 05 duramax hasn't done what I thought I'd see on MPG towing but it's not terrible.

Empty the truck will get 16.5-17 MPG around town if you drive it nice and use the hot street tune that adds about 100hp and 150 ft lbs. On the highway this tune has gotten me 19.7 mpg empty.

I have 2 different tow tunes, One is a modified tow tune with turbo brake and makes about 50 more HP over stock, safe tow tune for the transmission. I pulled that same 28 foot enclosed trailer across country recently. Truck and trailer empty and I would consistently get 11 mpg on fillups traveling 1800 miles. I loaded the trailer with a 4,000 lbs. car and had engine blocks in the bed of the truck, as well as cylinder heads, wheels and tires, and other car parts packed around the car inside the trailer. It was loaded pretty good.
Drove back 1800 miles and still got 11 mpg pulling. Most of this trip was a solid 70-72 mpg on the open highway.
I did try using cruise control for several hundred miles and gas mileage did drop to 10 mpg during those fillups, even though the truck never hunted for gears and towed fine this way, I still found better mpg using my own foot.

I have yet to try the other tune I can tow in, which is a modified stock tune with about 30 HP over stock and an extra 50 ft lbs, and has no turbo brake. Hooking up the trailer for another cross country trip and will use this tune to see if I can better 11 mpg.

[Firebirdjones]

More interesting stuff....

After reading both of those, you'll notice I pulled my 28 foot trailer loaded the same way with both of my trucks. What I have been most surprised about is that my duramax is only slightly better on MPG in tow mode. My old 454 getting 10 mpg and my duramax getting 11 mpg. Both trucks empty there isn't much comparison but I was surprised at how much I lost on the duramax when hooked to the same trailer, almost in line with my old gas truck.

The 454 goes down the highway at 2800 rpms while the duramax is loafing along at 2,000-2,200 rpms. I would guess it's in boost so much while pulling it's really sucking the fuel down, but that's just a guess.

I still wouldn't trade the pulling power of the duramax though. I'm hoping to better that MPG while pulling with a different tune. If I could just bump that up to 12-13 mpg it would save me about $200 in fuel cost for the whole trip.

[Cutlass]

I don't know what I can really do to get better mpg then I do now. The truck is about bonestock and flawless as can be expected for it age and mileage.
I guess to be fair, my "mostly" highway drive to work does include stop and go rush hour traffic on 1/3 to 1/2 of the highway drive. I'm rarely highway driving a full tank unloaded, but when I have come close to that, I'm up in the mid 16s. And I always hauling that boat around. All kinds averages out to 14s and 15s mpg. Winter time I'm low 14s and if I warm my truck up everyday I'm in the mid 13s.

[Firebirdjones]

I'm thinking that's really not all that unusual. I mean, give or take 1-2 mpg either way it's probably normal. Ya gotta figure you're asking a lot from a little 5.3 to pull stuff around. That's only 320-something cubic inches. So if you're hitting an grades at all depending on the terrain you're pulling in, I can see that little booger wanting to kick in and out of overdrive and hunting for gears all the time if you're going to want to maintain any kind of speed with it.

It would have to be, because even my dads 6.0 was doing that pulling a flat bed with a 4,000 lbs. car every time we hit a slight grade on I-71. He'd start falling back, and have to mash the throttle to find another gear and catch back up.

Extremely tough to expect gas mileage when the truck is doing that all the time.

Edit, just read your boat towing post. I see now you're pulling at 60% throttle and the truck rarely went into overdrive. So yeah my suspicion is right, it's working pretty hard. Not to mention these truck tunes that I've seen on HPtuner, enter PE mode with any throttle over about 25% which richens the AFR to about 11.5, probably for warranty reasons to keep the engine safe since these are trucks and knowing people will use them to pull and haul stuff.

[5.0THIS]

I don't know what I can really do to get better mpg then I do now. The truck is about bonestock and flawless as can be expected for it age and mileage.
I guess to be fair, my "mostly" highway drive to work does include stop and go rush hour traffic on 1/3 to 1/2 of the highway drive. I'm rarely highway driving a full tank unloaded, but when I have come close to that, I'm up in the mid 16s. And I always hauling that boat around. All kinds averages out to 14s and 15s mpg. Winter time I'm low 14s and if I warm my truck up everyday I'm in the mid 13s.

Keep in mind... rust holes create aerodynamic drag and could reduce fuel economy.

[0rion]

how you drive it when towing will make a noticeable difference. Just a couple mph in the duramax and I've seen a 1.5 mpg difference over a long distance. This last trip out I got right at 13 towing about a 10k camper and the truck was loaded with 5 people and as much shit as I could fit in it. That's a new personal best....normally it'll sit in the 12.2-12.4 range. That's my next thing to do....I want to scale it out and see just what kinda weights I'm looking at. My camper probably isn't quite 10k....I always just guess based on the dry weight and then the amount of shit I have in it. May be closer to 9k but somewhere between the 2. My buddy towed a 5k lb travel trailer last year with his 01 ext 4x4 5.3L. I would have to ask him to make sure but I'm pretty sure he saw right at 10 mpg and that was driving through Virginia which has quite a few grades. I would think you should see 10 mpg out of that set up. What's the weight on that boat? Drag is probably your biggest enemy. You have that boat sticking out and catching air and then you have the quads over the top of the cab. Just pushing a lot of air there.

[Cutlass]

The quads are the big parachute holding me back. I got 10.5 mpg towing a popup camper and 2 quads up there.
When I was drafting behind a semi, the throttle angle dropped to about 52%. Should done more of that
The best part of the drive was when I tried using the cruise control. Hit little incline in the road and the Trans downshifted to second at 65ish. That was a 4500 rpm wake up call

[Cutlass]

Yea I mean the truck felt plenty peppy and powerful until you get up to about 55-60 mph. Then you start feeling the air resistance and it only gets worse the faster you go.

[Firebirdjones]

The best part of the drive was when I tried using the cruise control. Hit little incline in the road and the Trans downshifted to second at 65ish. That was a 4500 rpm wake up call

Yeah that'll make ya jump. The dmax will downshift sometimes going down the mountains to slow down if you hit the brake pedal too much. It senses that and next thing you know it drops a gear or two and the tach is at redline, scares the shit outta me

[Firebirdjones]

how you drive it when towing will make a noticeable difference. Just a couple mph in the duramax and I've seen a 1.5 mpg difference over a long distance. This last trip out I got right at 13 towing about a 10k camper and the truck was loaded with 5 people and as much shit as I could fit in it. That's a new personal best....normally it'll sit in the 12.2-12.4 range. That's my next thing to do....I want to scale it out and see just what kinda weights I'm looking at. My camper probably isn't quite 10k....I always just guess based on the dry weight and then the amount of shit I have in it. May be closer to 9k but somewhere between the 2. My buddy towed a 5k lb travel trailer last year with his 01 ext 4x4 5.3L. I would have to ask him to make sure but I'm pretty sure he saw right at 10 mpg and that was driving through Virginia which has quite a few grades. I would think you should see 10 mpg out of that set up. What's the weight on that boat? Drag is probably your biggest enemy. You have that boat sticking out and catching air and then you have the quads over the top of the cab. Just pushing a lot of air there.

I've scaled my stuff out of curiosity. The Dmax weighs exactly 7,000 lbs with no one in it and a full 26 gallon tank of gas.

My 28 foot enclosed trailer is 5,100 lbs. completely empty. It's also 8.5 feet wide and probably 3 feet taller than the duramax, makes the truck look like a midget when it's hooked up, and that thing catches a ton of wind. I can see it in my rear view mirror as the large sheetmetal panels on the front of the trailer buckle in the wind, so much so that the sheet metal screws work themselves out all the time, I'm constantly replacing them and trying to glue them in
I know what each car weighs that I put in, had them all scaled. Chevelle for instance is 4,108 lbs.

I also carry a ton of gear in the trailer, a full tool box with an arsenal of tools, an air compressor, air tools, impacts, 3 spare tires for the trailer, a spare air tank, several cabinets that are full of cleaning supplies, towels, brake clean, complete carb tuning kits, gaskets, jets, spare carbs and distributors, 2 of the 14' by 14' EZ-up awnings for outside, 5 lawn chairs, a floor jack and jack stands, and a lot of other stuff I'm forgetting, Oh yeah a big ass gas powered generator for electricity when I need it. It's basically a rolling garage for anything that goes wrong. All that shit weighs a lot, don't know how much but that has to be several hundred pounds of crap in the front of the trailer. That's how I pull it all the time.

So the trailer and the car alone hit 9,208 lbs. Plus all that crap I listed above. I'm sure I'm 10,000 lbs. going down the road. 17,000 if you want to include the Dmax

My 79 1 ton pickup weighs 5,300 lbs. empty for what it's worth with one 20 gallon tank empty and the other 20 gallon tank full, so 20 gallons of gas.

[Cutlass]

I don't know about you guys, but I kinda get a kick out towing and hauling heavy stuff. Maybe I'm weird.

[Cutlass]

What's the weight on that boat?

Boat and trailer should be about 4000 pounds. No less then that anyways. No more the 5000 pounds I'm pretty sure. Never actually weighed it yet.

[Firebirdjones]

I don't know about you guys, but I kinda get a kick out towing and hauling heavy stuff. Maybe I'm weird.

I don't mind it. I get a kick out of pulling that 28 footer. It's always funny at a redlight I watch people coming up behind and pulling over in the other lane, expecting me to be slow. Light turns green and I take off faster than the guy in the other lane, and I watch everybody get back over again.

Another one is pulling up the mountains. We have steep grades that climb from near sea level to 6,000 feet in about 6 miles. The other side is even worse. Speed limit drops to 65, and most regular cars can't even maintain that speed up the mountain. I have a ball pulling up the mountain in the fast lane and passing cars in the slow lane. Cracks me up. I even passed a cummins pulling his smaller trailer up the mountain one night, he just looked over at me with this strange expression on his face I slowed for my exit about 5 miles up and he came around me still looking, haha.

[5.0THIS]

6000ft? Damn, how do you guys even deal with altitudes that high!

[Firebirdjones]

Lol, that's just where I get off my exit. You can keep going to Flag where the San Fran peaks are 11,000 or 13,000 ft, I forget which.

Too cold up there for me though

[0rion]

I don't know about you guys, but I kinda get a kick out towing and hauling heavy stuff. Maybe I'm weird.

I don't mind towing but I hate getting into heavy traffic with the trailer. Other people don't give a shit what you have hooked to the truck and actively try to kill you. I almost always have my whole family in the truck too so a lot of responsibility on me to get us there in 1 piece. The closer you get to the east coast the worse people drive. I-95 from DC down to Richmond is crazy and then I-64 out to Va Beach is about the same. I've never seen people drive so careless. If I leave a cushion between me and the car in front of me it's guaranteed that 3-4 people are going to dive in there and immediately hit their brakes. You have to be on a constant watch.


You need to get a duramax It's pretty impressive the power they have when hauling. That's where those trucks shine. Getting up to speed on an on ramp or something.....crazy how well it accelerates with all that weight hooked up behind it. I see on the RV boards people debating gas vs diesel to haul their campers. There is no debate once you've hauled with diesel. I wouldn't haul with anything else. These guys use the 5.3's to haul travel trailers because they fit inside the tow ratings of the truck.....those are the guys I pass going up hills with their foot to the floor and my truck never even down shifted.

[SMWS6TA]

About 2/3 of the accidents during the beach season around here are with trailers involved. We have a tunnel and bridge that was designed over 30yrs for 60,000 average cars and today get's well over 200,000 everyday during the summer.For the last 10 yrs the locals have been trying to get a new bridge built and so far the last 14 months it's go the farthest it's been in the process. Even if passed today it will still be 5-8 yrs till finish.