Fuel Mileage When Towing a Load. - Page 2

Cat Cracker · 12-12-2006, 03:58 AM

Are you guys serious on the fuel milage towing? I am buying a new truck, and I'm seriously considering a chevy/gmc. However, I currently have an '03 dodge H.O. cummins 6-speed, 1-ton srw quad cab 4x4, and when I pull my 36' toy hauler it gets 11-14 mpg, depending on wind, terrain, etc. I have driven a '07 chevy 3500 CC 4x4 dually and really liked it, but I need to know its gonna get better than 6-8 mpg pulling my camper. Please dont take this as a slam, and I'm not a "troll" trying to stir things up. I'm just tring to make an educated decision on my next tow vehicle. Thanks in advance for any input.

Cat Cracker.

**ob_1jr** · 12-12-2006, 04:14 AM

I say that if you truck now gets that good of mileage towing your camper, you should stick with it. The EPA has really screwed things up by making these trucks with stricter emissions. With the lowering of compression in the engine, there was a loss in mileage...couple that with all the emissions stuff on the new engine and ULSD....I would say that you would be lucky to get 12 mpg towing your 36' camper. I don't know that for a fact, but I find it hard to believe that you could much better mileage with a new truck. Your dodge has a inline 6 right? You are adding 2 more cylinders to burn more fuel with the GM. I can't promise you would get much better than you already are with your dodge. I know of one guy that bought a Chevy with the LLY engine and he was struggling to get better mileage than his other truck with a 454 in it pulling his 40' toy hauler. Don't get me wrong, I love the GM trucks, but the EPA is really screwing us over by making more strict emissions. I would go over to dieselplace.com and read what they are saying about the new engine and mileage they are getting while towing. I know I was disappointed with the mileage I got after hearing the claims that some people were getting. Well, I found out, my buddies claims weren't fact....I got better mileage than he did with his 7.3 PSD.

Kawtipping · 12-12-2006, 08:03 AM

The "new" engine isn't out yet. GM will not be putting them into trucks until January 1st. Any 07 built before Jan 1st will also not have all the extra emissions that are mandatory in 07 (07 being calender year, not build date or model year). I would expect 06 and 07 (pre-January) to get comparable mileage to your Dodge (depending on how you drive) seeing that the General put a 6 speed Allison in. Just remember that a brand new truck will have lower initial mileage until the engine is "broken" in. I can't say that I have towed a huge trailer with my truck. A 20ft open car hauler with 8 or 9 sleds is all I have first hand with. But with that load I still averaged 16 mpg. That was with a bone stock truck, traveling 80-85 down the interstate. My truck is an 02, so mine is still a 5 speed Alli. If you were to keep the speeds down (keeping the RPMs down too), I am sure 18 mpg towing at 65-70 would be easily reachable.

**ob_1jr** · 12-12-2006, 01:19 PM

Kawtipping,

The newer LLY and LBZ aren't getting great mileage like the LB7 did. Even with the 6 speed they aren't getting very good. Go read on dieselplace.com. Most of those guys are lucky to get 16 unload with a dually. Now to ask you....when you calculate your mileage, do you hand calculate it or use the DIC? I have an 04 with the LB7 engine and I never got 16 mpg towing. I towed a boat 300 miles round trip and I was running on fumes when I got back. (I never got above 70 mph since I was driving up the Haul road) I got 13 mpg on that trip with my truck running the stock 245s. The best I have gotten since was last year going to Arctic man pulling a 28' camper....I got 14 during that. Besides, running 80 down the highway is running nearly well over 2000 rpms with stock tires. The mileage on these trucks drop of dramatically over 2000 rpms. Were you going down hill with a tail wind? I'm sorry to sound skeptical, but if I didn't actually ride with you, I can't believe that one. I have found out most people either 1 don't calculate their mileage right, or 2 don't fill the tank up to the same spot as when they started. The LLY and LBZ, they lowered the compression from 17.5:1 to 16.8:1....that accounted for a mileage loss even though the 06 one had a 6 speed allison in it. BTW, I do get about 18 mpg empty and when I tow anything over about 2000 lbs, the best I get is 14 with my current set-up....my speedo is corrected for tire size verified with GPS.

On edit, I am just trying to give the best accurate info for people to make their own decisions. I don't want to inflate the mileage claims that some people have and have someone get pissed when they don't get anywhere close. Is it possible to get higher mileage towing....sure, but it is unlikely to see those numbers on a regular basis especially with a dually like Cat Cracker is looking at. I have driven my truck at all speeds and light accelleration to see what kind of mileage I get...no matter what I do I normally get pretty close to the same. So, I gave up and just drive how I normally do. Most of my driving is below 70 mph. I bought the truck to drive it and tow things. I get better towing with my truck now than I ever did with my 2001 silverado 1500 with the 5.3 gas sucker. That is all I care about.

Kawtipping · 12-13-2006, 08:13 AM

Figured out by hand of course. The 02 did not have a dic. Mileage divided by gallons added. Always fill the tank until foam will not allow me to add any more. My trip with the trailer was a 5 hour freeway jaunt with one stop between (the 2 other trucks needed fuel...both Dodges) Milwaukee and Minneapolis. Like I said, everything was stock right down to the rubber. It may have helped that the truck had the highway tires, and not the on/off road option tires.

Independent03 · 12-13-2006, 01:09 PM

Sound right to me. I just got back from Missoula Montanna the other day pulling an enclosed 40ft gooseneck for 3000 miles and I averaged 8.3 full going there and 9.6 on the way home. Granted i was going 75 / 80 mph the whole time.

Cat Cracker · 12-13-2006, 01:18 PM

Thanks for the information. I still haven't decided yet, and I know I'm running out of time before the "new" motors are here. (Dodge has a "new" cummins that is 6.7 liters and a diesel particulate filter) So, I don't want either of those. I like the interior and features of the chevy, and the ride is better, (IFS vrs. solid axel) the motors are real close (IMO) I like the allison way better than dodges 48re. (thats why I have a 6-speed

). Ofcourse the mega cab is huge, but I can only get a short bed, which is ok, I just have to get a different hitch. I have 5 children, so interior space is important, and I need an auto, because someone has to sit in the front seat with us, and the shifter gets in the way. Thanks again for the info, and I'm sure I'll have more questions soon.

Cat Cracker.

Roy W. · 12-18-2006, 04:34 PM

I did a recent 1300 mile unloaded trip at 75mph on the interstate and had a 18.2 mpg average hand calculated with the Edge EZ on #1. When towing my Jayco 32 foot travel trailer which weighs 9200 lbs at 65 mph, I average 11.2 mpg hand calculated.

duramaxdarrell · 12-18-2006, 06:34 PM

ive got the 02 3500 lb7 and pull a 40 ft gooseneck averaging 8 to 10 thousand pounds a load and am averaging anywhere between 12.9 -13.9 pulling loaded. without the trailer im some where around 17 to 19 mpg

newbuilder01 · 12-22-2006, 10:40 AM

I have a 01 ext. cab 4x4 short bed dmax. I recently pulled a 24' gooseneck flatbed trailer that maxed out at just under 14k. The load was two rows high of 60" round hay bales. I was pulling into the wind loaded and ended the day at just over 10mpg, with a bullydog power pup. My truck has a 24 gal. fuel tank and I used just over a quarter tank. On the second trip I used my moms 05 dodge cummins crew cab short box auto. Everything was the same, (this load was 200lbs less) she has a 35gal fuel tank, and it took almost half a tank. Didn't have time to compute the mileage. her computer said anywhere from 6-8, and her truck has 25,000 miles on it.