Diesel Truck MPG

[Camper_2012]

Do you guys know what would be the best MPG Diesel Truck to pull my 2012 26 Foot Fifth Wheel (7,580 lbs). Thanks for your help.

[Allworth]

2006 Duramax/Allison. Just got back from 1800 miles into the Smokeys and back with a 12,750 trailer, wife, grandson, dog, and junk.

10.1 towing (63mph max).

17.4 solo.

10.9 total.

[jmilner]

I have a 2005 Duramax 6.6. just pulled a 30ft fifth wheel . Total weight just under 21000 lbs and got 11.5 pulling and 16 to 21 without.

[sdetweil]

jim summers wrote:
... Also I'm baffled/troubled by
DEF. I don't have it now & read bad tales about it. Thnx

can't answer the truck questions.
on DEF they discovered if they spray some fluid with the right properties into the hot exhaust after the filter, it will combine with the remaining nitrous oxide (bad) and turn into water and nitrogen (good). doing this means they can run leaner (better mileage, less soot)

DEF Diesel Exhaust Fluid is that formula that works. Urea solution made with 32.5% high-purity urea (AUS 32) and 67.5% deionized water.

I use about 2.5 gals/4000 miles. a little more when towing.
I buy a spare 2.5 gal jug when I see them on sale. Last year towing at a truck stop, it was 2 2.5 gal tanks for $20. (instead of $15 each).

sometimes fill up the def tank at truck stops cause they have a nozzle and cheaper price. (~2.50 gallon)

[RedRam]

On my 04.5 Dodge I can honestly say I get between 9.8 and 10.2 when towing the 5'er in my sig.Empty it usually stays around 18 mpg and I don't get in a big hurry and the truck doesn't have any chips or engine upgrades.

[jim_summers]

My 2003 D'max has 90m miles on it. It sits idle half of each yr. when we
Lv AK & travel we tow a Nash 25r (10000lbs loaded). I drive at 59-61
Mph. That's when my D'max shifts into the highest gear at 1650 rpm.
That's w/ " tow/haul" also. I get an honest (pencil & paper) 12 mpg towing & 21-22 empty when we're Just touristing around. I'm looking at a new 2015 D'max. Anyone tow this slow Except me? What do new D'Maxs get at the slowest speed
Shifting into the highest gear while towing? Also I'm baffled/troubled by
DEF. I don't have it now & read bad tales about it. Thnx

[laknox]

NC Hauler wrote:

laknox wrote:

NC Hauler wrote:

laknox wrote:

Vulcaneer wrote:
Not sure I agree with everything that travelnutz has posted. But I do agree that the old Dodges and Rams I see here in the NorthEast do seem to not tolerate road salt well. Look at those that are 2006 and older, and their bodies, frames, do not hold up as well as the Bodies and frames on the Fords, or GM twins. On all makes of that age, the brake and fuel lines are either replaced, or need to be replaced.

Of course the Ford 6L, have other devastating problems. But they seem to hold up against the salt better than the RAMS/Dodges.

So considering that, if I was going to recommend a diesel of that vintage, it would be the GMC, or Chevy. The 2006 or 07. are very good models.

Just my opinion.

Also, if you stay to the early '07 Duramax, you don't have to deal with DEF, IIRC. I know that if I can replace my current '02, and I have the funds to play with, I'd =build= an '06 or early '07, with beefed up frame and current undercarriage to get the payload of the '14/15 trucks. It also would get registered as that model year, no matter what's "under the hood". 🙂

Lyle

Don't think DEF came out till 2010...believe you meant DPF which came out about the middle of 07.5, (EGR before that).

OK; whatever the extra cr@p you have to put in. I still find it somewhat amazing that the world's largest diesel engines, with 100,000+ cubic inches PER CYLINDER, are also the most efficient IC engines ever built for production =and= meet all current international pollution standards...running on heavy fuel oil. Why can't we do this with these puny engines so we don't have to have special fuel additives?

Lyle

Hey Lyle, I'm on your side..agree 100%, but I don't use any fuel additives....DEF isn't a fuel additive...wish we didn't have it, just like DPF or EGR, but guess if one wants a newer diesel, they'll have to get the EPA emissions that come on it...

I think OP is looking for an 05, which will keep him out of DPF, DEF and if not mistaken, the EGR, though it may have come out in 05...can't remember at this time.

My desire would be to =build= a truck on an early 2007 chassis, so no pollution junk and I could put a beefed up frame and an updated suspension under it with the most modern engine and transmission. Registration wouldn't be much more than my '02 D'max. 🙂

Lyle

[NC_Hauler]

laknox wrote:

NC Hauler wrote:

laknox wrote:

Vulcaneer wrote:
Not sure I agree with everything that travelnutz has posted. But I do agree that the old Dodges and Rams I see here in the NorthEast do seem to not tolerate road salt well. Look at those that are 2006 and older, and their bodies, frames, do not hold up as well as the Bodies and frames on the Fords, or GM twins. On all makes of that age, the brake and fuel lines are either replaced, or need to be replaced.

Of course the Ford 6L, have other devastating problems. But they seem to hold up against the salt better than the RAMS/Dodges.

So considering that, if I was going to recommend a diesel of that vintage, it would be the GMC, or Chevy. The 2006 or 07. are very good models.

Just my opinion.

Also, if you stay to the early '07 Duramax, you don't have to deal with DEF, IIRC. I know that if I can replace my current '02, and I have the funds to play with, I'd =build= an '06 or early '07, with beefed up frame and current undercarriage to get the payload of the '14/15 trucks. It also would get registered as that model year, no matter what's "under the hood". 🙂

Lyle

Don't think DEF came out till 2010...believe you meant DPF which came out about the middle of 07.5, (EGR before that).

OK; whatever the extra cr@p you have to put in. I still find it somewhat amazing that the world's largest diesel engines, with 100,000+ cubic inches PER CYLINDER, are also the most efficient IC engines ever built for production =and= meet all current international pollution standards...running on heavy fuel oil. Why can't we do this with these puny engines so we don't have to have special fuel additives?

Lyle

Hey Lyle, I'm on your side..agree 100%, but I don't use any fuel additives....DEF isn't a fuel additive...wish we didn't have it, just like DPF or EGR, but guess if one wants a newer diesel, they'll have to get the EPA emissions that come on it...

I think OP is looking for an 05, which will keep him out of DPF, DEF and if not mistaken, the EGR, though it may have come out in 05...can't remember at this time.

[laknox]

sdetweil wrote:

neal10a wrote:
There are too many human and physical variables to provide and good answer. The best way to tell is with dyno in a controlled environment. The coefficient of drag is about the same for all diesel trucks.

I don't think we need to get accurate to 3 decimal places. a range is what people need so they can plan effectively.

saying 9-12 is pretty accurate compared to 19-20.

my rule for my planning is total miles expected to travel/10 (mpg)
* $4/gal fuel cost. that gets me a close enough estimate

X2.

Lyle

[laknox]

NC Hauler wrote:

laknox wrote:

Vulcaneer wrote:
Not sure I agree with everything that travelnutz has posted. But I do agree that the old Dodges and Rams I see here in the NorthEast do seem to not tolerate road salt well. Look at those that are 2006 and older, and their bodies, frames, do not hold up as well as the Bodies and frames on the Fords, or GM twins. On all makes of that age, the brake and fuel lines are either replaced, or need to be replaced.

Of course the Ford 6L, have other devastating problems. But they seem to hold up against the salt better than the RAMS/Dodges.

So considering that, if I was going to recommend a diesel of that vintage, it would be the GMC, or Chevy. The 2006 or 07. are very good models.

Just my opinion.

Also, if you stay to the early '07 Duramax, you don't have to deal with DEF, IIRC. I know that if I can replace my current '02, and I have the funds to play with, I'd =build= an '06 or early '07, with beefed up frame and current undercarriage to get the payload of the '14/15 trucks. It also would get registered as that model year, no matter what's "under the hood". 🙂

Lyle

Don't think DEF came out till 2010...believe you meant DPF which came out about the middle of 07.5, (EGR before that).

OK; whatever the extra cr@p you have to put in. I still find it somewhat amazing that the world's largest diesel engines, with 100,000+ cubic inches PER CYLINDER, are also the most efficient IC engines ever built for production =and= meet all current international pollution standards...running on heavy fuel oil. Why can't we do this with these puny engines so we don't have to have special fuel additives?

Lyle

[Camper_2012]

NC Hauler wrote:

Camper 2012 wrote:

whistlebritches wrote:
We averaged 13.5 mpg on a 2 week trip to Tennessee, Georgia, South and North Carolina last summer, pulling a 37' 5th wheel with a 2003 Silverado Duramax/diesel. At home solo, we get 22 mpg. I understand the newer Silverado's only get around 16-17 mpg. And this is diesel.

Is your truck 6.6 V8? Thanks.

All Duramax diesels at this time that are in the 2500's and 3500's are 6.6L V8's.

Thanks so much for your help. I appreciate that a lot. Thanks.

[sdetweil]

neal10a wrote:
There are too many human and physical variables to provide and good answer. The best way to tell is with dyno in a controlled environment. The coefficient of drag is about the same for all diesel trucks.

I don't think we need to get accurate to 3 decimal places. a range is what people need so they can plan effectively.

saying 9-12 is pretty accurate compared to 19-20.

my rule for my planning is total miles expected to travel/10 (mpg)
* $4/gal fuel cost. that gets me a close enough estimate

[NC_Hauler]

Ric Flair wrote:
GMC is the best at everything. Even better than Chevy.

Nothing else to be added.

Lock the thread!

They're built on the same assembly line...How is the GMC better than Chevy, mechanically ,electronically, suspension wise, brake calipers, engine, transmission, wheels, axles and on? Other than cosmetic differences...that's it...oh...I owned Chevy's for years and years and years and in WV, VA and where I live now, in and around the area, the GMC alway's cost more. Status symbol?

[NC_Hauler]

laknox wrote:

Vulcaneer wrote:
Not sure I agree with everything that travelnutz has posted. But I do agree that the old Dodges and Rams I see here in the NorthEast do seem to not tolerate road salt well. Look at those that are 2006 and older, and their bodies, frames, do not hold up as well as the Bodies and frames on the Fords, or GM twins. On all makes of that age, the brake and fuel lines are either replaced, or need to be replaced.

Of course the Ford 6L, have other devastating problems. But they seem to hold up against the salt better than the RAMS/Dodges.

So considering that, if I was going to recommend a diesel of that vintage, it would be the GMC, or Chevy. The 2006 or 07. are very good models.

Just my opinion.

Also, if you stay to the early '07 Duramax, you don't have to deal with DEF, IIRC. I know that if I can replace my current '02, and I have the funds to play with, I'd =build= an '06 or early '07, with beefed up frame and current undercarriage to get the payload of the '14/15 trucks. It also would get registered as that model year, no matter what's "under the hood". 🙂

Lyle

Don't think DEF came out till 2010...believe you meant DPF which came out about the middle of 07.5, (EGR before that).

[NC_Hauler]

whistlebritches wrote:
We averaged 13.5 mpg on a 2 week trip to Tennessee, Georgia, South and North Carolina last summer, pulling a 37' 5th wheel with a 2003 Silverado Duramax/diesel. At home solo, we get 22 mpg. I understand the newer Silverado's only get around 16-17 mpg. And this is diesel.

Hold on to that truck. I too had an 03' Chevy D/A, ext cab/short bed 4/4 and towed a 37' 5er with it. Towed in the mountains of WV, TN, NC, VA and SC and NEVER got that kind of mpg while towing and I normally towed 55 to 62 mph...I NEVER came close to 13.5 mpg, more like 9.5 to maybe 12 IF I was lucky, (hand calc, far more accurate), but again, all mountain driving, but even when not towing, best I ever got was around 20mpg...in ideal conditions...

[NC_Hauler]

Camper 2012 wrote:

whistlebritches wrote:
We averaged 13.5 mpg on a 2 week trip to Tennessee, Georgia, South and North Carolina last summer, pulling a 37' 5th wheel with a 2003 Silverado Duramax/diesel. At home solo, we get 22 mpg. I understand the newer Silverado's only get around 16-17 mpg. And this is diesel.

Is your truck 6.6 V8? Thanks.

All Duramax diesels at this time that are in the 2500's and 3500's are 6.6L V8's.