8.1 vs. Duramax

[Elwood 2000]

A friend of mine owns a construction company. Went looking for a new tow rig for his largest box trailer (8.5'x24'). It is loaded with cabinets, tools, bench with saw, etc. About 7k lbs. total. At the local dealer, they have two '03 crew cab 4x4 duallys. Both set up the same, one red, one black, both with low 40k miles. One has the 8.1, the other the Duramax. After hooking up to his trailer on a day long test drive, the duramax had plenty of power up to about 40 mph, then started to fall flat. When getting to cruising speed, (55-60 mph), it had no power what so ever. He could have passed a car if he decided he wanted to, but it would have taken a couple miles. Top speed with the trailer was 68 mph, period. Without the trailer, it was like a race car, but with the trailer, he was not impressed much.

 

The next day, he demo'ed the truck with the 8.1. HUGE power improvement. Pulled strong all the way up to speed, passing was a breeze and he let off the gas at 85 mph as it would have climbed even higher. It drove like a totally different truck.

 

At first, I called "B.S.". The diesel should have kept with the 8.1 and got better milage to boot, but after doing another demonstration for me, I was shocked to say the least. I was still sceptical and wondered about rear end ratio differences, but these trucks are identical except color and engine choice. In the end, the 8.1 was going to cost $6k less money than the duramax. Personally, I was blown away.

 

My questions are these: Is this normal? Should the Duramax feel and act so sluggish? Do you have to pay a few thousand more for the diesel, then a few hundred more for power chips? I understand that the diesel will last longer (in theory) and milage should be better, but today gasoline is $2.10 and diesel is still $2.99. In the end, I asume the cost should be the same or maybe even advantage gasoline.

 

 

 

You guys own these engines, what do you think???

[Haulin' 8.1]

Yea though I drive the the valley of the shadow of Diesel,

I will fear no turbo;

For your horsepower art with me;

Your bore and stroke, they comfort me. - Haulin'8.1

 

or:

Torque is a measurement of twisting force, Horsepower is a measurement of potential to do work derived from torque and speed at which it is produced.

 

or:

Whichever engine has more horsepower will be faster with a level playing feild.

 

Vernon

[3500in nc]

well to fill u in

 

yes the dmax dose cost more most deisels do

 

a reason could be the rear gear as most 8.1l duallies have 4.10s and i think the dmaz runs like a 3.73 but i dont think that would make that much of a difference

 

but as a 8.1l owner ive never been at a loss for power while towing anything

 

just my 2cents

[TieRod]

What makes the D-Max soo popular is buy a programmer and add 200hp.

Most guys that ride with me when I tow are shocked at the power my 8.1L has.

[Shawn T]

I'm almost posative the Dmax your driving is a dud. I regularly pull my grandfather's 34' boat (12,500) loaded with hundreds of pounds of toys and equipment. I set the cruise on 75 mph on I-70. The truck NEVER leaves OD unless the incline is noticable. I have ample power for acceleration (remember 12,500 lbs!). I have never heard of any DMax owners say they are the least bit unimpressed with the towing capabilities. Usually everybody is pleasantly surprised. By the way, mine is all factory LB7, no mods whatsoever. Please don't start a Diesel vs Gas flame war! I have the utmost respect for the 8.1L. I am just telling you my experience with my truck.

[Elwood 2000]

I am not wanting to start a war at all, I am just very curious. While I am wanting a 2500 Suburban, if the right crew cab truck comes along at the right price, I would like a Duramax as well, but the performance astounded me.

 

I guess I was wondering if the Duramax performance I saw was typical. I would think not, but I have first hand experience with gassers for automotive applicaitons and diesels for farm(tractor) applications, and very, very limited experience with diesels in automotive applications.

 

Even if the Duramax truck is running 3:73 ratios instead of 4:10's, I would not think that much of a difference would be felt.

 

I am starting to think that SSTimothy is right and this particular one is just a dud.

[Shaners]

I agree that something might be wrong with the Dmax you rode in. My LLY is very strong and pulls like an ox. The heaviest load I've pulled was a small backhoe (total weight with trailer approx. 8000 lbs.). On an uphill entrance ramp to the interstate I was easily going 70+ MPH when merging with traffic (1/2 throttle or less). Once I blended with traffic I set the cruise and it never unlocked the converter in OD. I reset my DIC and I avereged 12.9 MPG's.

 

My friend has an 8.1L in his 2500 Avalanche, and I've driven it several times. I am very impressed with the smoothness and power of this motor. I have never driven it with any load heavier than a couple of quads behind it, but he does have a 27' travel trailer, and he says it pulls it with ease.

[SilveradoWV]

My 8.1 seems pretty strong when towing, i'd say it would out power any diesel from years past. In the 90's the Dodge Cummins diesel only had like 175hp and 400ft/lbs so the gas 8.1 was amazing compared to those diesels and can probably get the same jobs done as almost any stock diesel. However I would expect a duramax of the same year in the same configuration to be a little better.

[AmericanMuscle]

I had an LLY duramax in my last truck. Loved it!

 

I have an 8.1L in my new truck. I also really like it. The throttle response is better than the diesel and it's very snappy unloaded or even with a light load.

 

When it comes to towing power though, the Duramax was better. Towing my boat in the Ozark mountains, my Duramax only had to downshift on one of the steepest grades. It would have to drop back to 4th gear, but would hold 70mph up the grade. My 8.1L towing the same boat has to downshift all the time on smaller grades, and actually has to go back to 3rd gear and can't maintain speed on this same long grade. I can only run about 55mph with the rpm screaming.

 

LLY Duramax w/ 3.73 gears vs. 8.1L with 4.10 gears.

 

Gas mileage. I averaged 17.6 over the life of my Duramax. I'm at 50k on my 8.1L and my average is 10.2mpg. In all fairness, I tow an enclosed trailer a little more now than I did before, but at best my average would be about 11mpg with my 8.1L if I used it exactly the same as my Duramax.

 

I've been very happy with both of them. Neither one will let you down towing, but next year I'll be going with a Duramax again. LBZ here I come!

[byronlj]

I have owned both the 8.1 and the dmax. They both tow and run strong but the max will outpull the 8.1 without a doubt. Stay away from the dmax you test drove. Something is wrong with it.

Dave

[8100 Power]

Now that we've had truthfull towing situtions, how but running them stock to stock, dead stop to top end, how does each match up?

 

NO DIESEL AND GAS WARS, I JUST WANNA KNOW THE TRUTH.....

[Shawn T]

Now that we've had truthfull towing situtions, how but running them stock to stock, dead stop to top end, how does each match up?

 

NO DIESEL AND GAS WARS, I JUST WANNA KNOW THE TRUTH.....

 

<{POST_SNAPBACK}>

 

 

 

 

I can tell you from experience, because we have an 8.1L on plant site, I drive it regularly. The BBL is definately snapier and sounds awesome. The diesel has turbo lag that is inherint with all. Once the turbo spools up and you hit about 18psi of boost the diesel shines. More pickup in the midrange with the help of the turbo. Top end, has to go to the gasser, the diesel seems to only want to creep up around 90mph before it falls off of the curve. My verdict says, TIE. THEY ARE EXACTLY EQUAL. I'm stopping myself from replying to this post from here on out, because somebody is going to get on here and go off on one side or the other.

[NONSTOP SPEED]

I have to say personally the durmax can sometimes be a piece of s**t. This isn't a flame war start.... My reasoning behind this is my dad had a 01 4wd crew cab 8.1 dually w/allison and the thing was a gas guzzling beast. It would pull anything pretty much and never down shift up hill or anything. We have a 50ft car hauler which is pushing I'd say around 12-15,000 fully loaded and it would pull it 90mph in OD. He recently traded it off on a 05 duramax with the same setup and that thing is the biggest piece of s**t he has ever owned. It litterally wont start out on a hill without almost blowing up the tranny he has to put it in 4lo to get it up a hill pulling his trailer so I would say personally go with the 8.1. Definetly stay away from that truck. My dad has been trying to get GM to take his back because of the thing being such a gutless thing and the thing gets horrible gas mileage. Not pulling a trailer it only average about 13.5 mpg and his 8.1 would average 11.5. Looking at what other people have said on this board you might wanna test drive another one and see if it pulls any better.

 

Note truck were the same with the exception of the 8.1 had 4.10 gears and the duramax has 3.73

[Machine]

I’m amazed at these bad DMAXs that people are coming across. A properly running DMAX would pull 7K like it’s not even back there. Not being able to exceed 68 MPH should have raised an instant flag that there was something wrong with your sample. If a premium priced workhorse like the DMAX struggled w/ 7k – I have a feeling you would here many, many reports from pi$$ed off owners.

[8100 Power]

I have to agree with sstimothy, the BB does sound good, im just trying to decide wether it is worth going with the diesel, $300 for a 150 horse is not bad compared to about 4000 for a supercharger for the Bigblock...and also fuel milage is another big issue im concered about. I really have no need for a diesel, i like the 2500HD because of the way the set in the air and the looks of it, and of course availible power options ...I figured with a Duramax i could easily see about 17-19 mpg compared to my 8 and 9 that im getting.......of course that is after i get tired of flooring it b/c of the chip....