Just returned from a 4400 mile vacation, 3000 of the miles towing a 8000 lb ball trailer. I averaged 11.4 mpg while towing and varied between 14 and 17 mpg when unloaded. The towing miles consisted of one trip over the Cascades and two over Sierra passes. My truck is a 07 Laramie, 6 speed auto and as indicated in the topic a 6.7. All of the mileage was hand calced and the average towing speed was between 60 and 65 mph. I started the trip with 2000 miles on the odometer and changed oil before leaving.

The only notable occurance was a CEL about half way thru the trip. The CEL was only on briefly and never appeared again. The truck ran fine during the CEL.

I would give the truck a solid 9.5 rating, a strong puller and a smooth highway runner. I love the trans and engine brake but would mention some harsh downshifts when the tow/haul is on. I found for normal mountain driving the tow/haul alone is adeguate for braking. I did however engage both tow/haul and EB switch coming out of the mountains into Pendleton, OR and used together, no foot braking was needed and that stretch is one steep grade.

I should mention that I would have bought the 5.9 if it would have been available with the 6 speed auto and engine brake. However, with 6500 miles on the truck, I have no regrets. I have noted problems others have had with their 6.7 and consider myself fortunate. Also, I have read others here who have complained of poor fuel mileage particularly while towing. I believe, that their mpg would improve significantly by slowing their speed.

Thanks to all who have posted here with their experiences and observations on the 6.7. I have gathered alot of info here that is not available elsewhere.

Thanks again,

Bill
V

 

I also have a new 6.7 (about 4600 miles on it now). I've been towing a fifth wheel (est. approx 11,000 lbs) For about a month, starting in eastern WA and now in WI. I've hand calculated my mileage while towing to be about 11 MPG, same as you. I'm hoping mileage will go up as the engine brakes in.

2007 Hitchhiker II 29.5 LKTG 5th wheel

2007 Dodge Ram/6.7 CTD/SRW/SB/6-speed man/Big Horn Edition/16k Husky manual slider hitch

 

I also have been towing recently; started with 1400 miles on the odometer, and found that with the recommended towing break-in of 50 mph, I have to use the shift contoller to limit it to 5th gear (even in tow/haul mode) to keep it from shifting up and down at cruise. I upped the cruise speed from 50 to 55 when I broke 265 miles of towing, and it seems to like 5th gear still (it's only turning 1800 rpm at that speed). As soon as I hit 400 miles, I'll up the cruise to 60 and see what happens. I also have hand-calc'ed the mpg for towing so far to be 11.13; I'm sure it will inprove on tis relatively flat Texas terrain as soon as I can cruise at 65 - 70. All 5'ver towing so far. Empty milage so far is 14.5, but there really isn't enough miles on it to be concerned. Much of my empty miles driving are relatively short trips, or trips to the office in Dallas traffic. Should have a road trip to deer camp coming soon, then I'll see how the milage looks empty. (Not hunting trip, just 2-day work party trip). I am pretty impressed with my truck so far - only had a flash done for P245 code so far.

 

You guy's are all getting good MPG when towing. My 2006 5.9l gets 12 when towing so you all are doing great with the 6.7l.

 

I'd say! Nice view from the top though.

 

I just got back towing a 7000# load from atlanta to tampa doing avg 65-70mph. I filled up at 389 miles and it just hit 3 quarter mark. Im very impressed. I was even more impressed with gas milage that went up after install of air intake. 600 to the tank all highway doing 65-70mph.

 

ccoop,

I am interested in knowing which air intake system you installed. Also, your mileage is the best I have heard so far. I was able to run about 400 miles towing when the low fuel light came on and I considered that good.

Bill V

 

I have the afe stage 2 air intake with pg7 air filter. Paid 325 bucks shipped in 2 days from grimmperformance. I am really impressed with gain of mgp. Ease of install except for to bolts that go to bottom of kit which i did not do, and the stock bolt back in rad. shroud i could not do but could do with air tools on shroud. It really whistles now, thats for sure. Overall im happy, I would not take off silencer ring though as I think it whistles almost to much now

 

I recently towed this M151 from Lexington, KY to Auburn, AL for a customer and netted 13.8 mpg avg on the trip down there loaded and back unloaded.



I left out last Saturday around 4:59 pm and got back home Sunday morning at 8:02 am.......934 miles in 15 hours, averaging 62.3 mph or so.

My truck barely has 3800 miles on it as of right now.

By the way, the oil drained out nicely after the 934 mile trip upon making it back home.

Greg

 

Jeep looks to be a A1 ? Sweet lookin thou dad use to have one and I was rasied around military stuff all my life .

 

I find it increasingly funny that there are so many posts about fuel mileage on an almost 4 ton 408 ci 4 wheel drive best pulling truck I have EVER driven including some 18 wheelers!!! If you want fuel mileage buy a diesel vw or maybe even a diesel Mercedes or wait till the Smart 4/2 arrives in January but please oh please send me pics of a 5vr or tag with the jeep being pulled with one of them (lol) fof laughing.
Fred

 

I paid $3.35 a gallon for diesel in Nor Cal. I'm betting you wouldn't find that so funny! One hundred and five dollars for a fill-up! That will take the grin off anyone's face.

 

I just got back from my first trip towing with the 6.7. I Headed from Albuquerque up to Ogden Utah with an empty 25' gooseneck flatbed which weighs 4000# and averaged 13 mpg. On the way back the trailer had 10000# added for a total of 14000# and averaged a little over 10mpg. All this while running at 65-75mph. The 6.7/6sp auto pulled incredible. My other truck is a 97 Ford F350 CC PSD with a Banks Powerpack and the 6.7 CTD was in a completely different league. On my previous trips I would run as low as ~45 mph headed up Highway 6 from Salt Lake to Price, the CTD stayed at 60 to 75! I agree that the Tow/Haul/Ex Brake is pretty aggresive when lightly loaded, but when I had all 14000# behind me it was awesome! Comming down from Soldier Summit into Price Utah, I didn't need to touch the brake once on the steep decents. The truck was actually slowing down on the 6% decending grades. Dodge is gonna have to find a way to connect the Ex Brake to the trucks brake lights. These trucks stop so fast with the Tow/Haul/Ex Brake combo that folks behind you will need some warning.

 

I agree completely!!!!!!!!!!!!!! especailly with the brake light part

 

I don't have the auto tranny in mine, but I have been using the exhaust brake whenever I pull my 29' bumper pull trailer. Weighs about 8500#. I noticed the exhaust brake tends to surge or pulse on steep downhills. Is that normal, or should I have it looked at?

Thanks.