Chevy/GMC 6.0L Help Plz? Fuel Consumption

[FishinHatteras]

Fellow AS'ers,
I wanted to ask fellow folks what they are getting mpg wise when towing their rig with the 6.0L? I have never checked what kind of gas mileage I was getting while towing but decided to check it y-day. In a 92.8 mile span of use, I managed to get a lousy 8.5 MPG. That just seems too low. I was expecting closer to ten, more like 11.

My specifics: All tires inflated on the tow vehicle to 60lbs. I have not taken the time to check the tire pressure on the TT in about three weeks. That was pretty stupid on my part, and I should have checked it before we left. Going to go check them right now. I had no water in my tank, and hardly anything in the TV. Wife & two dogs, with minimal cargo besides my tool box & socket set. TT is a 28' Int'l Ocean Breeze. Tow vehicle is a 2012 Chevy 2500 Crew Cab with a camper top.

I have several questions:

Did I drive far enough to even GET a good average? We were coming back from Myrtle Beach, so we were steadily increasing above sea level.

What are you guys getting towing a similar rig? I have the 3.73 rear thankfully. I was trying to stay just under 70mph, and keep it in O/D as long as possible. I was trying not to fall below 65mph, unless on a steep hill. I wasn't getting into the throttle, but I wasn't trying to baby it either.

The only engine modification I have made was installing a K&N air filter. All else is stock.
What can I do to increase that MPG w/o spending a great deal of $?

We are trip planning to Phoenix, AZ this May, with stops in UT, CO & others. I am trying to determine what my fuel expenses are going to be. I was figuring around 11 MPG, but this sure increase the bill significantly.

Thank you for taking the time to respond to my questions.
Gavin

[warrenl55]

11 mpg avg. 2014 Ram 2500 with 6.4 Hemi gas 3:73 rear 4wd. Pulling 2014 27FB full load in bed and water tank full. About 6000 miles total in October. California via I40 to Blue Ridge parkway to home.

[field & stream]

Hi -- Here's my experience with a 2001 Yukon Denali, 3.73 rear, towing a 23' trailer (4,500 lbs empty) :

> drove from CA to CO to pick it up and got 18 mpg
> drove it home and got 11.5

Here's my opinion:

> With your trailer's empty weight of almost 6,000 lbs, your observed mpg is not surprising
> the difference in gas mileage between 60 and 70 mpg is significant.
> there are many other advantages to towing closer to 60 than 70

[moosetags]

We have towed our Airstreams with two different Suburban 2500's. Both of these Suburbans had the 6.0 liter gasoline engine. Between the two they had over 100,000 miles of Airstream towing. Our 2005 Safari 25FB weighed 7,400#. These Suburbans were an '04 and an '05 and had the four speed transmission and 3.73 rear.

Our long term gas mileage experience has been between 8.8 and 10.1 mpg. We usually travel on the highway at around 65 mph. We have always found that gas mileage while pulling a large trailer is very dependent upon prevailing winds and road grades.

I think that a 93 mile run is hardly enough to make any real mileage determination. A better run to get a real average mpg would be 5,000 miles.

Brian

[handn]

I think your fuel mileage is in the range of what to expect. I got similar mpg with a boxier trailer and a gas tow rig. With a smaller trailer and a 7.3 Powerstroke Excursion, I am consistently between 11.5 and 12.5. Diesels get about 20% better mileage than gas.
My driving habits are similar to yours--65 70 mph.
As Moosetags suggests, you could up your mileage by driving under 60.
There is real mpg and internet mpg, the latter is 30% to 40% higher but very difficult to achieve in the real world. Perhaps it is achievable going downhill with a tailwind.
Wind resistance is a big factor. I got 14 mpg for a 200 mile stretch with a significant tail wind when outrunning a storm and 10 mpg when busting into a big headwind.
I am always looking for a silver bullet to increase mileage. Stanadyne (a diesel additive) seems to give me 5% better mileage, but the cost of the product equals the amount of savings.
I did notice a boost of at least 5% when I switched tires from an offroad tread tire to a Michelin M&S.
The bottom line is that it takes a lot of energy to move your truck and heavy trailer down the road, but think of all the money you are saving on meals not eaten out and motels not stayed in.

[ckottum]

Use the tow/haul mode and set the cruise control at 60 mph, relax and enjoy the drive. If the transmission wants to shift up/down frequently, as it most probably will do in headwind and up even slight grades, manually shift down a gear as needed to minimize it and leave it there.

cheryl k

[cwf]

My friend has 2012 2500 6.0 gasoline. Tows a SOB with square front. His mileage about 10.5-11.0 here in Texas Hill Country. Worse on windy days. Speeds similar. Sounds like you are not unique on mpg.

[spclkaz]

I've towed my 94 30 ft. Excella FK around for about ten years with a 99 GMC 2500 with a 6.oL gasoline engine out here in AZ and the rest of the West. The trailer weighs over 9,000lbs and I usually tow with empty tanks if I know I can get water when I get where I am going... I keep very careful mileage records... I always engage the tow/haul mode... on the freeways I set the cruise to about 62 or so... I consistently get around 9.5 -11 MPG when towing... that's over a 15 year period...

[Seabloom]

Hi Fishin,

I have a 1976 Overlander (6200 lbs empty) and tow with a 2012 GMC crew cab 6.0l with 4x4, also the 3.73 gears. While towing my trailer I average as other users have indicated about 9-11 mpg. For sure every mph above 60 the mileage gets increasingly worse. I used to have a 9ft long camper in the back of the truck which only weighed 2000 lbs. At 60 mpg I could hold about 12 mpg, at 70 mph I was down to 8.5 mpg. For me the interstates are the real killer, I just want to get there but it is a cost vs patience exercise.

[murreywalker]

Originally Posted by moosetags

We have towed our Airstreams with two different Suburban 2500's. Both of these Suburbans had the 6.0 liter gasoline engine. Between the two they had over 100,000 miles of Airstream towing. Our 2005 Safari 25FB weighed 7,400#. These Suburbans were an '04 and an '05 and had the four speed transmission and 3.73 rear.

Our long term gas mileage experience has been between 8.8 and 10.1 mpg. We usually travel on the highway at around 65 mph. We have always found that gas mileage while pulling a large trailer is very dependent upon prevailing winds and road grades.

I think that a 93 mile run is hardly enough to make any real mileage determination. A better run to get a real average mpg would be 5,000 miles.

Brian

I will offer the same as Brian.

I get between 8.5 - 11.5 depending on terrain and an average speed of about 65 mph in our Suburban 2500 (2013).

I suspect a 6.0 is a 6.0 is a 6.0…

[Jack46]

We previously had a 2008 Suburban 2500 that came with the stock 6.0L, but we added a 4.10 rear end. We would get 9-10 hauling our 30' FC (a lot less in the mountains).

[Rascal0729]

I tow with a 2006 4500 Topkick Dura Max Diesel get 5.5 mpg

[KWN306]

I have learned on my 2000 Dodge 2500 4x4 with a 3.73 rear that the sweet spot is between 60 to 62 mph, will get me about 14.5 mpg. If I am hammering it; it will go down to 9 - 10 mpg and that is with a camper shell on the bed of the truck, it drops 2 mpg without the camper shell.

Slow down and smell the roses and you mileage will increase greatly.

[jcanavera]

I've got a 6 liter 4.10 axle in my 3/4 ton GMC van. We do between 11-13 mpg towing our 30' slide. The 4.10 allows us to do most of our towing in OD, except when we get into hilly terrain. In those cases we manually drop down a gear as we assend the hills.

Jack

[EarlM]

I also would recommend leaving it in tow haul mode when towing and don't worry about gas mileage there are too many variables, ethanol v/s no ethanol, 87 grade fuel vs's higher octanes.

enjoy the ride the difference is not significant. just spend your kids inheritance and have fun

I like to run 70 mph

earl

[johncook]

11 is about what to expect at 60 MPH
I have a silverado 2500 HD with the 6.0

[1Boyscout]

Originally Posted by FishinHatteras

Fellow AS'ers,
I wanted to ask fellow folks what they are getting mpg wise when towing their rig with the 6.0L? I have never checked what kind of gas mileage I was getting while towing but decided to check it y-day. In a 92.8 mile span of use, I managed to get a lousy 8.5 MPG. That just seems too low. I was expecting closer to ten, more like 11.

My specifics: All tires inflated on the tow vehicle to 60lbs. I have not taken the time to check the tire pressure on the TT in about three weeks. That was pretty stupid on my part, and I should have checked it before we left. Going to go check them right now. I had no water in my tank, and hardly anything in the TV. Wife & two dogs, with minimal cargo besides my tool box & socket set. TT is a 28' Int'l Ocean Breeze. Tow vehicle is a 2012 Chevy 2500 Crew Cab with a camper top.

I have several questions:

Did I drive far enough to even GET a good average? We were coming back from Myrtle Beach, so we were steadily increasing above sea level.

What are you guys getting towing a similar rig? I have the 3.73 rear thankfully. I was trying to stay just under 70mph, and keep it in O/D as long as possible. I was trying not to fall below 65mph, unless on a steep hill. I wasn't getting into the throttle, but I wasn't trying to baby it either.

The only engine modification I have made was installing a K&N air filter. All else is stock.
What can I do to increase that MPG w/o spending a great deal of $?

We are trip planning to Phoenix, AZ this May, with stops in UT, CO & others. I am trying to determine what my fuel expenses are going to be. I was figuring around 11 MPG, but this sure increase the bill significantly.

Thank you for taking the time to respond to my questions.
Gavin

You did not say what your TT weighs. I pulled a 34' TT, 8200lbs, 62 to 65 mph, with a 2003 1500HD, 6L. I averaged 8.5 to 9.6. A K&N Filter did not help mine any. I bought the truck new, I use it most for towing. It only has 33k miles now.

The only way I found to help MPG is to park it.

[dannydimitt]

Keep it out of overdrive and don't get over 60 and SHAZAM ! you just might get that elusive 11

[larryglarson]

I have a 2014 Silverado 5.3 with 3.09 or so high speed rear end and pull a 2014 30' Classic. I do not use Tow Haul and drive 55 to 60. On a 5,000 mile trip from Iowa to the Pacific NW I got 11.5. Yes, it shifts more and is slower up the hills, but I like the mileage.

[phbarnhart]

Used to tow with a 2012 2500 Suburban. Your numbers seem about right given your speed and elevation change. The way that vehicle is geared, there's a huge difference between 60 and 70mph.