Increase Fuel Mileage While Towing?

[MTRiverRunner]

I have a stock 01 2500HD, I have been really pleased with the fuel economy up until now. I get around 18 to 21 MPG. I recently purchased a new boat (probably about 5000Lbs) and my fuel economy has dropped to around 10 MPG when towing. Any mods that I can do to improve this? I have the short bed and my 26 gallon fuel tank doesnt give me much range at 10MPG. I have thought about chipping it and putting an exhaust on, would I get much improvement in my fuel mileage? Any advice would be greatly appreciated.
Thanks

[moss6]

I'm not sure how the 01' responds to mods as compared to a 06' LBZ that I have; but from my ongoing experience my advice is be very careful with what you change from stock and definately don't believe everything you read. On the LBZ the addition of an EDGE with Attitude was a good mod, in the only setting I use the mileage setting the performance non-towing is much improved and mileage is somewhat improved. Towing I can not tell that there is any difference in mileage or power (12,000 lb fifth wheel). After I added cold air and a Banks exhaust things went to hell when I towed. There was a big loss of power and the water and exhaust gas tempretures were much higher than stock, on average the truck had to use one gear lower than what it did before. This of course 180 degees from my intent-----great investment. Right now I'm still trying to make the thing run right with the mods installed but its really looking more and more like a lossing battle. Most likely the exhaust will have to be taken off crushed and thrown in the dump--the cold air will then be evaluated alone as to its fate.

[NutNbutGMC]

I have a stock 01 2500HD, I have been really pleased with the fuel economy up until now. I get around 18 to 21 MPG. I recently purchased a new boat (probably about 5000Lbs) and my fuel economy has dropped to around 10 MPG when towing. Any mods that I can do to improve this? I have the short bed and my 26 gallon fuel tank doesnt give me much range at 10MPG. I have thought about chipping it and putting an exhaust on, would I get much improvement in my fuel mileage? Any advice would be greatly appreciated.
ThanksNot uncommon. After you read the board for a while, you'll find this is a typical characteristic of the early LB7. I have had two LB7s and neither of them got your top fuel mileage. But I drive them hard too.

As for a mod, all I'd do (in my opinion) is put a tune on it and leave the rest of it alone. Keep reading the board, and as well use the keyword serach and find archived articles of the past. There is a lot of good info archived from back in 01, 02, 03 when this engine was coming of age.

$0.02

[Mark Rinker]

There were major programming changes made after '01. Kennedy Diesel can reflash your ECM with the updates, and also equip it with a tow tune that will help both power and mileage.

We have put over 200K on two early LB7s - and average 12-13 with 30' trailer and average 6K loads.

What size of boat? How fast do you tow it? Something doesn't sound right.

[MTRiverRunner]

THe boat is a 22 ft but it weighs probably about 5000 lbs and has a really high windshield that probably causes quite a bit of wind resistance. I usually tow at around 70 MPH but I always have hills to go up and down.

[DmaxMaverick]

I have a friend I camp with frequently, and we have nearly identical trucks, only his is a 2003 and he has 265 tires, and mine are 285's. He complains about his mileage all the time. Every time we go somewhere. We have very similar 5'ers, same mod's on our trucks. Pretty much the same except the year models. I get 12-15 towing, he gets 8-10. He says he doesn't understand it. Well, when we go on a trip, I leave early or arrive late. He drives like every stop sign or light is a drag race. He drives 10 over the speed limit (55 in CA). He has to pass someone (just because he can) if the vehicle in front of him is going 1 mph slower than he wants to go. I'm amazed his mileage is as good as it is. Well, you can probably see where this is going. I got him to follow me on one trip. Told him to drive like I did. He thought the results were amazing. He got nearly the same mileage I did. Go figure. His response: What fun is that? Said he got bored and nearly fell asleep. Just can't drive that way. Well, he doesn't complain about his mileage anymore.

Before you start looking for problems with your truck, have a close look at your driving habits. Speed kills. Anything over about 60 MPH will exponentially decrease your mileage, and more with heavier winds. The most often overlooked indicator is your braking habit. If you are a heavy braker, you're gonna get crappy mileage. Anytime you have to brake during normal driving, you are burning off the fuel (again) you used to get to that speed. Of course, braking is necessary, but unnecessary braking wastes fuel. My friend's brake pads are wearing at twice the rate mine are. I'll probably get 150K+ out of mine, and he'll be ready for a brake job before he hits 75K.

[Mountainman]

Hey Mr. DmaxMaverick, I couldn't agree more with your driving tips. I believe you're the first one I've read that even mentioned braking. As a young lad, I drove an over-the-road tow truck for an auto salvage company. No, I wasn't trying to save them money but heavy braking and relying on heavy braking are also safety related. When towing, you quickly learn to look ahead, use your mirrors and scan to each side or you can get in trouble in a hurry. And it also holds true for driving when you are not towing.
How's that little one doing? Hope all are fine. Jim B.

[MTRiverRunner]

You are right, speed is the single most important factor relating to fuel economy, with my old tires (4 ply 255s), I would get 24 MPG at 55 -60 MPH and about 20 at 75 mph (not towing). THe thing is that the spd limit in Montana is 75 on the freeway and 70 on the two lane secondary roads. I usually tow about 250-350 miles one way to where I launch my boat. It always seems like I am racing daylight and have a long way to go so I usually drive around 65 to 70. I know that my mileage would go up if I drove 55 all the time. But if I have a 700 mile round trip, it takes 10 hours at 70 or about 13 holurs at 55. 3 hours is a substantial savings in time. What I am wondering is if there are any mods that I can do to increase my mileage across the board while towing, or am I just stuck with 10 MPG if I go 65-70?

[mr. monte]

I agree with the "speed kills"

I notice, the slower I go, the better the economy, wind plays a major factor too

I'm getting 13-14 mpg, pulling about 8-9000 lbs car hauler going less than 65 mph

[Mark Rinker]

I was talking to a trucker on I90 in western Montana. He was flying along with something under his tarps. Turns out, they were Boeing aircraft wings from NJ, headed to Seattle. Total cargo weight of only 6,000#, but using up all of his 54' flatbed.

Asked him what his mileage was with that light load.

His answer: "6mpg".

Asked him what his mileage would be fully loaded to 80K GVW.

His answer: "5.75mpg".

Asked him what his mileage would be empty.

His answer: "6.25mpg".

This is why we are seeing many more 'light duty', for-hire rigs on the road, pulling wedge trailers, hydraulic boat trailers, etc. As fuel prices spiral upward, the economies get stronger and stronger for the hotshot hauler, as we get a nice relief from fuel consumption when running empty, or light.

The semi is designed and geared for max load carrying capacity. It is very inefficient when run empty, or light. That being said, the most fuel efficient truck on the road (when considering cost per mile per pound of freight) is still a fully loaded semi.

However, if your load is 20K# or under, and cannot be combined with other freight due to dimensions (aircraft wings, overdimensional boats, etc.) then the most efficient is probably a 15K# 'Hotshot' load behind a Chevrolet Duramax, getting 13-14mpg loaded, and 15-16 empty with trailer.

The parallel from my first career as a mainframe computer programmer is uncanny. We thought the PC would never replace the mainframe, and it hasn't. However, the number of small, dynamic applications that were better suited for PCs has grown exponentially, as the number high volume, big data applications best suited for mainframes has remained about level. I think the same will continue to happen in transportation.

Both computing environments were/are still valid. Both semi-trucks and hotshot haulers are valid. The key is directing the demand to the proper platform. If you want to go make some money with your underutilized Duramax, check out this site:

www.UShip.com (http://www.UShip.com)

p.s. Disclaimer: Before hauling for hire, read both your local state regulations and USDOT regulations online, or in a little green book available at any truckstop. Consult your insurance company. Investigate cargo insurance.

[93GMCSierra]

That is a very good post, My brother has a 99 1 ton dually dodge, with the 5.9 diesel an a 43' 3 car hauler he is looking to supplement his job income with car hauling, short distances of course, His fuel mileage loaded is better then 15 mpg.

[DennisG01]

THe boat is a 22 ft but it weighs probably about 5000 lbs and has a really high windshield that probably causes quite a bit of wind resistance. I usually tow at around 70 MPH but I always have hills to go up and down.

Don't forget your trailer and gear/gas/oil/batteries, etc. Your trailer alone could easily weigh another 1,200lbs - 1,600lbs for that boat. Also, IMHO, I think boats are about the worst "thing" to tow when it comes to aerodynamics. It's not just the top side of the boat...