Looking at these parameters, you can see how they are pretty reliant on the ability to get the load moving and up to speed. This is where the 3.92 will outshine the 3.21.
That table is a great summary. Motortrend has a great article on it as well:
Maximum trailer tow ratings have been a bit of a mystery over the years. Manufacturers each had their own somewhat secret ways of determining how much weight th
www.motortrend.com
The biggest problem I have with the standard, is how people fixate on the numbers without realizing which numbers actually matter to them in real life situations. For a start let's compare the v6 with a 3.92 to the v8 with 3.21. The v6 is at 7300 pounds and the v8 at 8200 for a CC 4x4 with the 5.5 foot bed.
So 900 pounds separate the two according to J2807, but I can guarantee you in real life everyone will notice there is a large difference in towing power. Cost of truck/fuel aside, everyone would much rather tow with the hemi.
And again my whole point in this thread was not that the 3.92 is a poor choice, it's not. It's a great choice for many people, but its not going to make a difference on the highway at 62 mph (the context of this thread).
So while the 3.92 can launch you quicker off the line, how many people need more power than the 3.21 has off the line? How many people absolutely bury the pedal from a dead stop while towing and need more than that? When I bury the pedal, its because I need to get on the freeway or pass a trucker.
The standard doesn't account for the fact that 99% of the time I'm towing, I'm sitting between 3rd and 7th. Obviously this number differs depending on your location and towing habits, but how many people need to launch from 0 to 30 repeatedly on a grade in less than X seconds?
That's the problem I have with the standard. It tells you what the truck can do, but not how relevant that "doing" is to my needs.
It's a very similar thing to reports like "truck X has 75 problems per 100 vehicles" and "truck Y has 80 problems" ... ok. But now qualify those on a scale of importance, because losing my transmission in a truck is far worse than having my bluetooth occasionally not pairing.
I'm not saying I have a solution to this, we need the standards and they are a good thing, but it's important to look at the entire picture without fixating on a specific test.