Hi,


I need some opinions from the people that tow all the time.


I tow a 27ft Toyhauler which weighs about 6,500 pounds empty. I consistently get 10-11MPG. On the same trip, same speed, when the trailer is fully loaded at 13,000 pounds I get exactly the same mileage.


Does this make sense??


The only thing I have changed are the tires went to 265/75/16.


I just ordered a Banks exhaust and K/N filter to drop my EGT and hopefully get a little more HP.


I was talking to a trailer hauler and he said that it might be the aerodynamics of the trailer and that some trailer tow a lot harder than others.


By the way my speed is around 60 MPH around 1800-1900 RPM and have 16,000 miles.





2003 2500HD 6.6 Duaramax,4X4 CC SB, Nicktane, 50G Transferflow,Banks 4" exhaust (any day), Michelin LTX MS 265/75/16, Leer 800

Marco Polo,


I would be curious to see if the Banks helps you. I could almost swear that I lost milage when I installed my 4" exaust. It is not because it is a Banks, just because it is bigger. I think in the end, having the correct computer programming to match what you are doing is key for milage and drivability. How do you calculate your milage?


ON EDIT. The Baks did help with power and produces good sound. Just no milage gains. Probally a loss of 1 MPG. I need to upgrade to a tow tune soon!Edited by: Bronco

I pull a 32 foot travel trailer. It's about 9 feet tall, plus the air conditioner on top. It weighs about 5200 pounds empty and the RV dealer says people put 800-1200 pounds of extras in it for food, camp supplies, etc. I run right around 70 mph when towing, give or take a little depending upon traffic in the slow lane and the availibility of space to get over into the passing lane. My truck is pure stock with no mods what so ever, with 10K miles on it (I haven't towed since the end of October with about 8K miles on it). I run anywhere from 9.5 mpg to 11 mpg. Personally, I think it should do a tad better (I was seeing 8.5 to 9.0 mpg with my half ton Z-71 5.3L 3.73 axle), but the truck doesn't lack for power, so I guess that's what I live with. Personally I have a hard time believing people when they say they are getting 12-14 mpg, towing larger and taller trailers than me. Maybe I'm jelous, but given what I see with mine, I don't believe the higher mpg claims. Maybe it's some kind of new math.


marco polo, I think you are right in the ballpark with me in terms of what we are getting.

I have not pulled since September. Pulling a 7-8k 5er in the Utah Mountains, I got 10-12. 10 when mostly up hill and 11.5-12 when mostly down. Truck is stock with swischeese airbox and Amsoil air filter.


Likewise, I wonder about the 12-14 claims unless they are all level with a tail breeze.


Truck has 25k and am looking toward warmer weather and more use of the 5er.

I pull a 38' fiver that's 13'-6" tall and 8'-6" wide and get between 7-9. The biggest thing that made a change in my mileage that I've noticed was changing tires! I would get between 8-10 before I went to 265's. My fiver weigh's more than GM says the truck can handle (around 17,500) but I have to say that with a total weight around 25,000 I'm still impressed with how it does. I have to belive that areodynamics do play a part.


Marco,


What's hidden in that Toybox and where do you go play?

I've pulled my same trailer now with three vehicles I've owned. I have a Carson 16ft (20' ball to bumper) dry weight is around 3500lbs. I figure I weight in at 4k or 4500lbs.


94 Z71 x-cab 5.7L 285's = 5-6MPG on hwy couldn't do over 65MPH no matter what. I blame the taller tires and gears.


02 2500HD CC 4x4 8.1L/A 285's = 8-9MPG (flat freeway at 70+) 10-12MPG @ 55-60MPH. But at least I could do any darn speed I wanted on any hill.


04 2500HD CC 4X4 D/A 285's =10MPG on flat 70+mph 12MPG+ 55-60 in the hills. Again can do any speed I want on any hill. And the MPG is getting better every trip.


my funniest towing bit was north of the Grand Canyon pulling down hill in a head wind so bad I down shifted going down a steep grade. I slipped the Allison into neutral and if felt like someone threw out the boat anchor. Had two complete flash brown outs (dust storms) in 10 miles. I couldn't even see the front of my truck. Boy did I burn a few tanks of gas that trip.


cmcEdited by: CMC-GMC

I get 10-12mpg pulling our 10,000lb 5er. I had 265's on the truck and recently "downgraded" to 245's as I couldn't get the 265's to wear corectly no matter what pressure I tried. Trying to go out this weekend and get some early camping in, will post results from that trip on Sunday or Monday to see if it goes up any....may not due to winter fuel, who knows. On the flats I don't notice too much difference between my "old" 8.1L, but in the mountains, both power and mileage are excellant! Was getting 5-6mpg towing in the mountains with the 8.1L. Trading up to the DMAX was the best choice I could have made.


Bob

Thanks for all the replies.


It looks that we are all getting the same MPG when we tow. 9-12 MPG. My aerospace buddy said my rear end on the trailer is creating an air brake vacuum which results in substantial drag. He suggested an air spoiler right above the ramp. Yeah right!!!


Terrain Twister we have motos and 4X4 ATVs. We like Jawbone and Red Rock area. We do a yearly trip to the Paiute trail in Utah (Favorite location). Check out www.irv2.com (http://www.irv2.com) and go under the toyhauler section. We went to Ocotillo Wells for XMAS and are planning a President and Easter trip. Where do you live in OC? Are you going to go to the Dyno day in Torrance in February? I might see you over there. There will a lot of people from Dieselplace.


4X4man were you running the 265 with the OEM rims? I am and I can see they are crowning. I need to get 8" rims.


2003 2500HD 6.6 Duaramax,4X4 CC SB, Nicktane, 50G Transferflow,Banks 4" exhaust (any day), Michelin LTX MS 265/75/16, Leer 800

I think that a lot of differences you are noticing are from the aerodynamics of the specific trailers that people pull. I know there is an engineer type that hangs out on RV.net that did a little research and came up with some formulas to determine how much horsepower it takes to move a rig at a given speed on a given grade of hill. It's novel but to boil it down, "the more frontal area you have exposed to the wind stream, (plus drag coefficients, etc), the more horsepower, (fuel), it is going to take.


With my 30ft. Trail-Lite, (6000 lbs), being pulled by my Grand Cherokee I got about 12 mpg. I have not pulled with the 2500HD yet, but I am expecting about 15 mpg.

Marco Polo-


Yes I was running the 265's on the stock PYO's. The 265's require a 7 inch wide rim, while the PYO's are only 6.5". Others don't seem to have any problems doing it, but for some reason I couldn't make it work. Oh well. Maybe once these 245's are worn I will look at a tire/rim combo.


Bob