Legal vs recommend tow ratings for 8.1L Burb/Yukon XL

[dkad260]

While in the hunt of a 2010+ Denali, my other option is the 8.1L SUV.

Being in the market for the 8.1, obviously it comes down to either the 3:73 or 4:10. I've gone back and forth between a 2500 P/U SRW and the SUV, and while a 6.6L 2500 would cover my towing needs, I'm really after the extra interior room.

Please correct me if I'm wrong but trying to determine the legal or recommended tow rating for these platforms.

I'm looking for the option to haul a boat on occasion and with a load of fuel, water, gear would come in at about 10,500-11,000 lbs.

So the 02-06 Burb/Yukon 2500 w/ 8.1L has a max tow rating of 12,000 lbs with the 4:10, 10,300 lbs with the 3:73/2WD, and 10,100 with 3:73/4WD.

I've found a few very good condition vehicles with the 3:73, I could swap the gears but would prefer finding one with the 4:10. If I go with the 3:73, is the 10,100 lb 4WD limit a manufacturer's limit or the legal limit...or both? A few troopers I've spoken with have stated if I was to be weighed, they are going to look at the door sticker and make sure the axle weights are met, along with the registration.

Does the 4:10 model have the same 8600 LB GVWR as the 3:73? As well as the 5500 lb rear axle weight limit? From what I understand, the chassis is the same on both axle ratio models, same class V hitch, just the fact the trans should live longer on the 4:10.

To be clear, I'm not trying to hook up 12K lbs to the 3:73 version and haul up and down the coast. I'm not trying to side-step safety, I don't like to tow at the limit but this would be about 10-20 miles from the marina to the house. My issue comes down to if I load it up with fuel and water, I'm looking to be about 900 lbs over the limit on the 3:73. I doubt I would get pulled over but I don't want to chance it.

So my questions are:

Is the published GCWR of the 3:73 the same as the 4:10? What do the owners of each version have on their registration as far as the GCWR? Please don't share personal info. I could tag my vehicle for 900 lbs higher but would that even make a difference in the eyes of the law? Seems they are more interested in commerce vehicles than recreational toys but they know what they are looking for.

If we were talking different engines, axles, bearings, suspension, then I wouldn't question the ratings, but from what I understand, its only the 10% difference in axle ratios, which is not necessarily a small number.

Please feel free to correct and criticize my post, I'm also learning more about these platforms as I go.

Thanks!

 

[Big Mama]

Is this rig just for towing or a DD when not towing?

 

[dkad260]

Is this rig just for towing or a DD when not towing?

At the time of purchase, it won't be a DD, but used occasionally when not towing. My current DD (Envoy) has 294K miles so the GMT 830 could possibly become a DD for awhile.


This is a tough call over a 6.0 2500 HD. The P/U wouldn't be used to tow any great distance with that much weight, merely short-haul relocation. I'd almost be OK with a 8.1 Avalanche but the 6.0 would return better unloaded mileage.

However a 2500 GMT 830 is far better for a family trip, 2nd row captain chairs that recline.....just not possible in a P/U.

 

[adriver]

Just throwing out a guess: I wouldn't expect any trooper to have any clue what your tow rating are, or the weight you are towing, let alone pull you over because of the gearing they would never be able to tell that you have... I would think the bigger concern would be if you ever got into an accident. If the insurance company could show you were even 5 pounds over the max rating they could say you were unsafe being over loaded, them trying to say it was your fault. This probably wouldn't even matter in a simple traffic accident, but lets say you get caught in the wrong place at the wrong time in something serious, and there is an actual investigation.... (just a thought).


If the only thing changing is the gearing for the increased tow rating, that tells me, that to "safely" tow that vehicle (most likely in the worst conditions up a hill), you have to be ABLE to accelerate that much weight. The 4.10 gearing allows for more torque so you can increase the weight, and still be able to "tow with at least a minimum requirement of 'rated' acceleration".


If this is over mostly flat land, my guess is the biggest concern is getting it off the ramp. The 4wd/AWD might be a much better option, even though its not going to improve your tow rating (on paper).


Also, if you are willing to do modifications to your vehicle. An e-fan (if its 2004 or earlier), exhaust and tune, will make up the difference in the 6.0 vs 8.1 and still give you that fuel mileage for $1-$2K depending on exhaust setup.

 

[dkad260]

@adriver , I agree about not likely not being bothered by the law.....but also wanted to add that if I bought a 3:73, then swapped ring and pinion to a 4:10, then how does the legal tow rating change? That's one area I want to understand as far as being legal on paper.

Which leads to your other point of liability, not trying to sound judgemental, but we know how insurance companies can be. The 2 areas would be accelerating and engine braking, but heaven forbid a serious accident, just being on the road would look bad in their eyes.

I can tow a little above 12K with something like an 08 2500 HD 6.0 w 4:10, if I went with a P/U, I would prob try to find one newer than 06.

 

[wjburken]

@adriver , I agree about not likely not being bothered by the law.....but also wanted to add that if I bought a 3:73, then swapped ring and pinion to a 4:10, then how does the legal tow rating change? That's one area I want to understand as far as being legal on paper.

Which leads to your other point of liability, not trying to sound judgemental, but we know how insurance companies can be. The 2 areas would be accelerating and engine braking, but heaven forbid a serious accident, just being on the road would look bad in their eyes.

I can tow a little above 12K with something like an 08 2500 HD 6.0 w 4:10, if I went with a P/U, I would prob try to find one newer than 06.

I had a conversation about this topic a few years ago with a friend who is an Iowa DOT Patrol officer. He said no matter what mods are made to a vehicle, they only consider what is on the sticker put on by the OEM or what the ratings of the tires are (which ever is lower) when looking at whether a vehicle was over legal towing/cargo capacity.

 

[dkad260]

I had a conversation about this topic a few years ago with a friend who is an Iowa DOT Patrol officer. He said no matter what mods are made to a vehicle, they only consider what is on the sticker put on by the OEM or what the ratings of the tires are (which ever is lower) when looking at whether a vehicle was over legal towing/cargo capacity.

That pretty much mimicked the conversations I had, I forgot to also include the tires in my earlier post....thanks for adding that.

The tow rating on my SWB Envoy 4.2 w/ 4:10 is 6200 lbs, my registration came with a 11K GCWR. I had it weighed with a full tank of fuel, no persons aboard and was 4720 lbs. Not much room for persons and cargo.

But the numbers that count are the 11K on the registration, tires, and axle weights on the door sticker. I was able to raise the GCWR to 11,500 for a safe margin at time of renewal.

 

[avalonandl]

How much do you plan on towing? I had an 04 2500 Avalanche 8.1 w/ 410's. It was a beast. I routinely pulled my 31 ft offshore cat 11k on the scales. It did it fine. Then I had a 15' Duramax . It would tow ANYTHING. But found the punishing ride too tough.

But I sold the dmax and plan on towing my 35' Donzi CC - OB's about 9500# with my Denali about 35 miles at the end of the season.

 

[dkad260]

Nice Donzi...

My battery almost died on my last post. Meant to add that if I can tell the DMV to change the GCWR to 11,500, then where does the legalities come into play? I'm going to assume in the event there was an accident and they needed to investigate...but that I'm not sure. Not like I'm towing an 863 Bobcat with a Rav 4.

I plan on towing either a 26' or 28' cruiser. The 28' would weigh approx 10, 500-11K wet w/ trailer.

 

[adriver]

I had a conversation about this topic a few years ago with a friend who is an Iowa DOT Patrol officer. He said no matter what mods are made to a vehicle, they only consider what is on the sticker put on by the OEM or what the ratings of the tires are (which ever is lower) when looking at whether a vehicle was over legal towing/cargo capacity.

That pretty much mimicked the conversations I had, I forgot to also include the tires in my earlier post....thanks for adding that.

The tow rating on my SWB Envoy 4.2 w/ 4:10 is 6200 lbs, my registration came with a 11K GCWR. I had it weighed with a full tank of fuel, no persons aboard and was 4720 lbs. Not much room for persons and cargo.

But the numbers that count are the 11K on the registration, tires, and axle weights on the door sticker. I was able to raise the GCWR to 11,500 for a safe margin at time of renewal.

This seems like something that if it came down to it, that you could get information from the manufacturer for comparing trims or options, and testimony from an "expert witness" ( a certified mechanic with years of experience, an engineer, or from the manufacturer themselves), and be able to present your case quite well, if you were to do mods after the fact to compensate. I'm sure some internet searching would come up with something that's happened before towards a full legal process.