GM 6.0 gas V8 vs Duramax 6.6

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I have pulled with both gas and diesels and it is unreal how much difference the Duramax makes. You will also be gaining the benefits of the Allison transmission. I highly recommend the Duramax, you won't regret it!
 
I'll vote for the Diesel if you're going to do quite a bit of towing.  If the truck is a daily driver with very little towing its a harder decision.  You can't beat the driveability of the Diesel.  As others have said, its nice to tow in the 1500 to 2000 rpm range, even climbing steep grades.  The six speed transmissions are a big part of that performance.  They always have the right gear and never make a large downshift when climbing a grade, although mine very rarely needs to shift out of the top overdrive.

I had the oil changed on my truck today after driving a little less than 8000 miles driving from TX to Alaska over the last two months.  We've pulled the trailer about 6000 miles, while the rest driving the truck alone.  I totaled up the fuel and it figures at about 13.1 mpg so far.  We took a pretty good hit early on when we pushed against a strong headwind for about 2000 miles until we got to Dawson Creek BC, getting about 9.5mpg at 65mph.  Once we got onto the Alaskan Hwy and slowed down, it got a lot better.  Our rig loaded is about 16000 lbs.  The loaded trailer has 6700 lbs on the axles, while the truck weighs 9300,loaded hooked to the trailer and 100 gallons of fuel on board.  I've proven that its possible to put enough weight in a 3/4 ton truck to pretty well max out the GVWR when pulling a relatively light trailer.
 
I can't argue the "diesel is best for towing" comments - I agree! There is no comparison for the low-end grunt and hill climbing ability that a diesel offers. If I had an extra $5,000 to spend and if I was consistently towing 10,000 lbs or more, my new GMC wouldn't have any spark plugs. However, I can tell you that the 6.0 does a great job with my 8,500 lb TT (only about 2000 miles on her so far!). It is a world of difference from the 2002 I traded in. It should work even better with a TT in the 6,000 lb range.

The tow/haul mode does wonders with the shift points and it's now a 6-speed tranny that provides an engine braking type feature - it will automatically downshift while braking (even when not towing) and will hold a constant speed downhill if you have tow/haul and cruise on.

In it's relatively short life so far, I've averaged 14.5 MPG in normal driving (2 more MPG than my 2002) and about 9 MPG towing.
 
I have been away from my computer for a few days and unable to reply. I cannot thank each of you enough for helping me with my question. You have certainly provided excellent responses which will be very helpful to me moving forward. Thank you again.
John Dibble
Punta Gorda,FL
 
We have a 2007.5 GMC ex cab w 6.6 duramax/allison tranny combo. You'll love the tranny when in moutains hardly touch the breaks. Set cruise and scurry over hill and dale and never even know trailer is behind you in tow mode. The reason I say set cruise is because if you don't before  you know it you will get a ticket for speeding at least in Calif..
 
Or drive all 3 brands of trucks...Ford, Chevy, Dodge...Lets be honest and throw all bias aside.  They all three make good trucks.  Drive them all and see which one suits you best.  I do recommend the 1 ton however...My guess is your desire for a bigger trailer will come faster than needing a new truck. 
 
My two cents. I bought the duramax. Between the big 3, i got the best deal on the Chevy and don't forget 5/100,000 on Chevy and dodge. 2011 models will all have the urea injection.

I have towed very little so far with this truck, but have towed up 34ft goose necks loaded with live checkens (yes chickens) with the big block Chevy. they were stout 1 tons but got terrible fuel mileage and pulling on a hill the pedal was on the floor.

i have pulled my fiver 2 times and will take a long trip labor day weekend. I'm pulling 34ft and 13,600lbs + the veh weight. I can tell you loaded i could pass another veh going up hill, (not that i would) it has worlds of power and torque.

I would go with a diesel, yes they are more expensive, cost and upkeep but resale will be higher and you won't regret it later if you up-size in what you tow. City/highway mileage i am getting 16 mpg. Talked with other duramax owners and they average 20-22 mpg highway unloaded once broken in and 16-18 mpg loaded.

From what i hear you will get the best fuel mileage with the dodge pre urea. Not sure on the 2011.

A one ton will only cost you a few dollars more and give you more tow capacity. I went with a 3/4 ton cause i don't pull all the time and and like the looks better.
 
Well here's my .02.
I think that if your only planning on towing 2-3 months out of the year and plan on driving the truck maybe to work or on a fairly consistant basis the rest of the time, I would go with the gas, but in a 1 ton. My reason for saying that is one the inital cost of the diesel, two the higher cost of maint, and three the higher cost of fuel. Now if you were towing 6 mo or more, or pulling a large trailer, as in 30 plus ft, then I would reccomend the diesel for all of the above mentioned reasons.  A person, as much as a lot of guys will argue this, has to work a diesel truck pretty constantly to make the money spent worth it. If I were in your situation thats what I would do, I had even thought about buying a diesel a few years back to drive daily untill I played the #s game and realized how much I would be spending just to have that power a few times a year. But hey thats just my opinon.
 
Peanutman said:
My two cents. I bought the duramax. Between the big 3, i got the best deal on the Chevy and don't forget 5/100,000 on Chevy and dodge. 2011 models will all have the urea injection.
Click to expand...
That is not entirely true.
For 2011 the only Dodge trucks using the urea system will be the 4500/5500 series C&C
All Cummins diesels up to and including the 3500 dually will continue with the existing system as first introduced in January 2007.
 
Perhaps the sales guy i was talking with was wrong. They will all have them soon. government mandate i think or at least that's what i have been told.
 
Saw a 2011 Silverado 3500 on display at the NY State Fair this weekend - crew cab, SRW, loaded to the gills - $61,000...OMG!

The Duramax was a $7,100 option. My first truck cost $7,400 new! I'm getting old.
 
We gave some serious consideration to going diesel on our last truck.  The price difference between the diesel and my 6.0 Chevy gas was about $14,000 and I did not NEED the diesel, just wanted it.  The price is made up of the engine option (about $7000) and the required Allison transmission (I really like the new 6-speed auto with manual selection) and the fact that you cannot get the diesel as an option is a basic truck.  Which is what I wanted.  What used to be "basic" is pretty well equipped for me.  What I was told is that you are required to get a model that has power windows and carpet and a sound system that any teenager with hearing issues would be impressed with.  The difference was about twice the cost of the diesel engine alone. 

Maybe next time and with a heavier trailer that helps me justify it. 
 
COMer said:
...the fact that you cannot get the diesel as an option is a basic truck.  Which is what I wanted.  What used to be "basic" is pretty well equipped for me.  What I was told is that you are required to get a model that has power windows and carpet and a sound system that any teenager with hearing issues would be impressed with...
Click to expand...

A disappointing trend with auto manufacturers that seems to get worse every year. "I'd like the chrome wheels please." "Sure thing - that comes with the Preferred Customer Package - a deluxe glove box light, leather seats, navigation system and 16 cup holders!"
 
It's called "drag". You package a low-sales item with a hot one to raise the sales of both. And of course, the income you get from them. Another form of this is packaging 2 or more of an item together when most people only need one.  The sales cost is the about the same, but you nearly double the revenue.
 
Another diesel vote here. I love my dmax, if I buy another one it will be a 2006 or early 07 with the LBZ dmax and a 6 speed trans. The LBZ puts out 365 HP stock and doesn't have all the emissions crap that the new diesels have. If you buy a diesel and keep up on the maintenance, and it will last a long time. Like others stated the Allison transmission is the best by far. Check out duramaxforum.com and find all the info you want about the dmax. 
 
I am sure by now you have picked your truck and trailer combo.  If not I say Diesel all the way no matter which one of the big 3 you get.  I own a 01 Chevy 2500 with a Duramax and the 5sp Allison.  It pulls a Raptor toyhauler weighing 14,000lbs.  I have taken it from NY to GA a couple times set the cruise at 67 and it never skipped a beat. I averaged 10mpg.  I have a friend that towed my trailer with his 02 Chevy with a 8.1 BB Vortec with an Allison and he was averaging 4-5mpg.  His truck never had a problem either just used twice as much fuel.  Good luck on your buy!

I do also recommend get a 1 ton also.  I am at the max with my set up. If I want to go bigger I need a new truck.
 
Actually, you may be way over capacity already, I may be wrong but I thought the GCWR for an 01 3/4 ton Chevy was 16000, maybe I'm wrong, I know it shot up to 22000lbs soon after but if your trailer is rated for 14,000lbs and your truck weighs 7000 you're over if the GCWR is 16.
 
The 2001 also have a 22,000lbs GCWR, and a GVWR of 9,200lbs.  Which when I had my truck weighed it was at 6,900.  So I am at the limits on both sides.  I looked into it pretty hard before I bought the trailer.  Dealer said it was a 3/4ton towable 5'er and I had to make sure.  I still wish I had a 1 ton dually.
 
I did some checking but every site I went to never made it clear, I think the 22000 is for the dully but it says the GVCW goes from 16000 to 22000 so that's why I thought the 22000 was for the dully. O agree, watching those SRW tires squat with the weight of that five makes me wish I had a dully at comes too. A rear blowout while towing 65+ is never good.
 
At first I thought the same thing but the 2500 and 3500 have the same GCWR.  Your difference in the two comes at the GVWR.  The reason they have the same GCWR is they have the exact same drivetrain from what I understand.
 
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