Chevy diesels what is your MPG?

[KyDan]

DW and I are dreaming of a step up in trailer size. She retires in a year
and so we're looking at 5th wheels.

Bought a 2007 2500HD Silverado alison/duramax turbo with 72,000 on it.
We immediately hitched up (like the next day) and towed our little
7 1/2 foot wide 4200 LB ultra lite to Florida and back to KY.
Total trip right at 2000 miles.
We kept track of every gallon of fuel and mile.
Over the entire trip I averaged a dismal 10.5 MPG

I know the Ford guys and the Dodge guys will also chime in but I'm
trying to compare apples to apples.
Chevy duramax guys-- what is your honest MPG??

If you have made modifications- what were they and how much did
they improve your MPG?

I'm not in love with this truck-- it's a work truck so doesn't have as many
of the creature comforts as my 04 1500.
I may just sell it and stay with my current rig. (Current truck has 44,000
and garage kept and looks NEW.)

We are struggling to decide if we keep what we've got--
see my signature- or keep the diesel and maybe move on up trailer wise.

What are your real life MPG figures??

[BarryD0706]

Our very low mileage 2013 3500HD SRW generally gets 11.5 mpg towing our 14k 5er. I'm hoping that may improve as it gets more miles on it. I had 15 mpg for about a 100 mile leg on our last big trip. Must have been a tail wind and slightly down hill.

[Cajun Po-Boy]

MPG's before my professional tuning:

16-city driving (unloaded)
18-hwy driving (unloaded @ 70mph)
10/11-towing 12K 5'ver @ 60mph

[brokenaxle]

I keep about 65-70 mph towing and get around 14 mpg. My old 1/2 ton gasser got no more than 7 mpg towing. If your truck is out of warrenty I know guys who put a chip in his and doubled his milage. I was told putting one in will void your warrenty though. I don't care what the Ford and Dodge guys say I've driven them all and owned Dodge and G.M. I believe the GMC truck is a much better product. At least here in Mi parts are easily available and less expensive. Also My GMC has been way more reliable and comfortable to drive than the others I have driven. Oh yeah I do between 19 and 24 MPG while not towing. I switched to an more agressive all terrain type tire and my Milage dropped about 2 MPG.

[K.G.campers]

I had a 2006 2500 with the LLY 6.6 and it got 20mpg on open highway....probably around 16 in town, and 11 pulling my 10,000 lb travel trailer. I'm pretty sure you have the LBZ motor and I'm surprised that your mileage is as low as it is. Now I have a 2008 3500 with the LMM motor and it's even worse....but that is due to the DPF (diesel particulate filter) that the EPA made the manufacturers install whick chokes out the motor. Somewhere in 2007 is when they started putting the LMM engines in trucks so you may want to find out if it is the LMM motor. If it is then that's why your mileage is so poor. I think all manufacturers lost alot of mileage once they were forced to install these devices. I'm still considering taking mine off and going with an after market exhaust system.

[KyDan]

Originally Posted by Ragin Cajun

MPG's before my professional tuning:

16-city driving (unloaded)
18-hwy driving (unloaded @ 70mph)
10/11-towing 12K 5'ver @ 60mph

So what do you get WITH a tuner??

[Herk7769]

The good news and the bad:

After much discussion with folks at campgrounds using the 2500HD with Duramax towing all kinds of stuff from "my size" (9,000 pounds) and up to 15,000 pounds (yep found WAY more than I believed possible); the fuel economy is exactly the same as I get. (yep, hard to believe, but the folks towing the big Montanas and Cedar Creeks with 2500HDs get 10.5 -12.5 MPG like I do.)

Not ONE of them has ever weighed their rigs (afraid to most likely) but all report "no problem" towing them.

If I had to give you "an average" for all conditions it would be 11.5 MPG.
You do realize WIND and SPEED are the biggest determiners in MPG when towing (camper frontal area being equal).

Towing into a headwind will KILL your MPG since the headwind velocity must be added to your speedometer speed to calculate the drag on your camper.

A tailwind on the other hard gets subtracted from your speedometer speed for the same calculation.

Since DRAG uses the SQUARE of the perceived velocity, wind and ground speed (speedometer reading) has a huge effect on what you get for economy since engine power has to overcome it as you drive.

[KyDan]

Originally Posted by K.G.campers

Somewhere in 2007 is when they started putting the LMM engines in trucks ...I'm still considering taking mine off and going with an after market exhaust system.

I have that funnel shaped vortex exhaust pipe.
I'm pretty sure this means I have the late 07 version with the added
soot removal stuff.

[KyDan]

Hey Lou, thanks for the info--

I hear folks saying what their "dry weight" is all the time!! It's so EASY to
drive up on the scales and find out REAL numbers.

Our current trailer was weighed twice on certified CAT scales.
That 4200 number includes EVERYTHING necessary for a week in the woods.
Including at least a half tank of water.
My trailer is an early 08 and it is only 7 1/2 feet wide and not very tall
compared to a 5er.
Later models are all 8 feet wide.
Still I know wind resistance is my enemy.
I wonder about wind resistance with a 5er.
They are SO much taller than me and wider than my truck but the nose
of a 5er is closer to the cab of the truck. Maybe the wind flows up
and over the front of the truck and then continues up and over the 5er
and total wind resistance might be comparable or even less than what I
get??
Only a wind tunnel would tell that I guess.

On our recent trip we were driving long haul distances every time so
I was pushing it at speed limit all the time. I stayed in the right lane
as much as possible but we weren't in economy mode for sure.

I was hoping for 12-13 with my little trailer but we weren't even close.

[grayfox]

Originally Posted by KyDan

I have that funnel shaped vortex exhaust pipe.
I'm pretty sure this means I have the late 07 version with the added
soot removal stuff.

The early 2007 actually got a little better mileage. Checkout the thedieseplace.com/ lots of info.

[RubenZ]

Originally Posted by herk7769

The good news and the bad:

After much discussion with folks at campgrounds using the 2500HD with Duramax towing all kinds of stuff from "my size" (9,000 pounds) and up to 15,000 pounds (yep found WAY more than I believed possible); the fuel economy is exactly the same as I get. (yep, hard to believe, but the folks towing the big Montanas and Cedar Creeks with 2500HDs get 10.5 -12.5 MPG like I do.)

Not ONE of them has ever weighed their rigs (afraid to most likely) but all report "no problem" towing them.

If I had to give you "an average" for all conditions it would be 11.5 MPG.
You do realize WIND and SPEED are the biggest determiners in MPG when towing (camper frontal area being equal).

Towing into a headwind will KILL your MPG since the headwind velocity must be added to your speedometer speed to calculate the drag on your camper.

A tailwind on the other hard gets subtracted from your speedometer speed for the same calculation.

Since DRAG uses the SQUARE of the perceived velocity, wind and ground speed (speedometer reading) has a huge effect on what you get for economy since engine power has to overcome it as you drive.

I agree with that. I've towed different weights from small 4k trailers to our current 7500lb trailer and never noticed any big difference in mpg's between the trailers. I too average about 11mpg's give or take. I have to admit that using a Predator Tune set to MPG gains helped my NON towing mpgs to around 16-18 mpgs. I know people who are getting close to 20mpgs non-towing and I call BS on that.

[lbrjet]

You may have had a south breeze going down and northern breeze coming home. I wouldn't read too much into MPG from one trip. My first 600 mile run was under 8. My average over 4700 miles that year was 9.25.

[grayfox]

Originally Posted by RubenZ

I agree with that. I've towed different weights from small 4k trailers to our current 7500lb trailer and never noticed any big difference in mpg's between the trailers. I too average about 11mpg's give or take. I have to admit that using a Predator Tune set to MPG gains helped my NON towing mpgs to around 16-18 mpgs. I know people who are getting close to 20mpgs non-towing and I call BS on that.

I can get 19 to 20 HWY on a regular basis with my 05 D-Max unloaded ( no BS). I drive like I want the best fuel economy. In my opinion you have to find the sweet spot to get the best fuel economy. My sweet spot seems to be right at 1800 rpm.

NO tuner !! Not worth it to me unless you want more power.

[puff]

As already stated speed and road conditions are the MPG killers. I don't have a duramax but have a GMC with a 6.5 Turbo diesel. Towing my 14k girl she gets 10-12 maybe more depending, maybe less. I have figured out that I am not going to get there first or to the top of the hill before grandma n grandpa on a sunday afternoon drive.

It's the adventure and the drive not the speed at which I arrive. If I want speed I hop on the bike.

[TURBS]

Originally Posted by rubenz

i agree with that. I've towed different weights from small 4k trailers to our current 7500lb trailer and never noticed any big difference in mpg's between the trailers. I too average about 11mpg's give or take. I have to admit that using a predator tune set to mpg gains helped my non towing mpgs to around 16-18 mpgs. I know people who are getting close to 20mpgs non-towing and i call bs on that.

[grayfox]

Yep Turbs, I get around 11 to 12 towing 12,000 lbs. and I have seen as much as 22 mpg but, not very often. It takes a lot of discipline to hold to the sweet spot but, it does pay off as well

[Helmsey]

Originally Posted by KyDan

Bought a 2007 2500HD Silverado alison/duramax turbo with 72,000 on it.

Is it the old body style (classic) or the new body style? If it's the new body style you will have all of the emissions junk on it that really kills MPG.
If it is the classic body style you will have a lot more options on getting better MPG out of it.

[TURBS]

Originally Posted by grayfox

Yep Turbs, I get around 11 to 12 towing 12,000 lbs. and I have seen as much as 22 mpg but, not very often. It takes a lot of discipline to hold to the sweet spot but, it does pay off as well

As you said it can be done .
That's 12 miles of interstate and 30 miles of two lane which has a town every 6 miles.

[jevanb]

my mods are as follows and I have a 06 with the LBZ
larger exhaust from the turbo outlet back
PPE modded air box
airdog lift pump
trans upgrade
EGR blocked
pyro and boost gauges
EFI tuned on a DSP5 switch
stock tires at 80PSI
syn fluids all around
and a bunch of other stuff that do not effect milage

modified stock tune at 70mph winter fuel 19mpg, summer fuel 22mpg
heavy tow tune with 13k 5er 12.5 mpg @ 65mph
economy tune winter fuel 21mpg summer fuel 23-24
race tune 3-23mpg 'o yea' but the tires don`t last long

[ependydad]

Originally Posted by grayfox

Yep Turbs, I get around 11 to 12 towing 12,000 lbs. and I have seen as much as 22 mpg but, not very often. It takes a lot of discipline to hold to the sweet spot but, it does pay off as well

Cruise control liberally is the only way that I hold my speed down!