Upgrading to a 6.7, but which?

[Synolimit]

Well FYI for the price I ended up with a 2022 3500 6.7 dually 3.7 with 58k.

1. I’ll leave it alone because I’m covered for 100,000 miles and 5 more years.

2. Just going to add some 33’s or 1 size up as they fit better.

 

[CrispyBacon]

The guy still insists on doing a mod that will hurt the truck/towing.... Lol

Does he not realize that towing and payload capacities are based on stock configuration? As soon as he adds more weight to the wheels, he's losing out on capability..

 

[Synolimit]

The guy still insists on doing a mod that will hurt the truck/towing.... Lol

Does he not realize that towing and payload capacities are based on stock configuration? As soon as he adds more weight to the wheels, he's losing out on capability..

Lol 100% realize. Pretty sure a 5300 payload and 32,000 towing isn’t gonna care to much from an extra 1.3” diameter or 0.65” taller in ride height and 7lbs per tire of rotational weight. That loss of 3hp and tq is really gonna kill me!! Haha

 

[Synolimit]

The guy still insists on doing a mod that will hurt the truck/towing.... Lol

Does he not realize that towing and payload capacities are based on stock configuration? As soon as he adds more weight to the wheels, he's losing out on capability..

Lol the difference from the 3.73 to 4.10 is 1,360lbs towing or 0.37 final drive. Going to a 255/80/17 I’ll be around 3.59 or 0.14 final drive difference. Lol I think I’m good losing around 500lbs of towing.

 

[nlambert182]

Lol 100% realize. Pretty sure a 5300 payload and 32,000 towing isn’t gonna care to much from an extra 1.3” diameter or 0.65” taller in ride height and 7lbs per tire of rotational weight. That loss of 3hp and tq is really gonna kill me!! Haha

It's not going to be 32k lbs of towing... trust me. That's what it's advertised as but in reality you'll max out on payload long before you get to the 32k lb mark. If you calculate the real tow capacity based on a 5,300 lb payload (20% pin weight) that's a max tow weight of 26.5k.

This is all before you factor in things like cargo, people, a hitch, etc.. If you've got more than a 2wd tradesman model your payload is even lower than that. With something like a Laramie or a Limited, you're probably in the 4,700-4,800 lb payload range (23.5k actual tow capacity). Could even be slightly lower. That's almost 10k lbs less than advertised.

That's still good and plenty of payload to handle most things so don't get me wrong. It's just not what the advertisements say and a lot of people don't realize that. Anything that you change on the truck (such as tires) reduces the payload further. 500 lbs (your numbers) doesn't seem like a lot of payload to lose at 5,300 but if you lost that at 4,700 you're down into the 4,300 lb payload range. If you factor in 500 lbs of cargo, people, a hitch, etc... payload is now in the 3,800 lb range before you even hook a trailer to it.

If you're set on bigger tires, I would at least recommend that you make sure you're running the proper type of tire on the truck. I'd look for a load range E tire for sure. If you intend on changing wheels, make sure they're rated to handle the psi of the tires. Dually tires are capable of running much higher pressures (and you'll need it) for towing larger loads.

 

[Timsdually]

Lol the difference from the 3.73 to 4.10 is 1,360lbs towing or 0.37 final drive. Going to a 255/80/17 I’ll be around 3.59 or 0.14 final drive difference. Lol I think I’m good losing around 500lbs of towing.

I wouldn't buy anything but a 4:10. The acceleration from a light or passing is noticeable from a 3:73.

 

[Synolimit]

It's not going to be 32k lbs of towing... trust me. That's what it's advertised as but in reality you'll max out on payload long before you get to the 32k lb mark. If you calculate the real tow capacity based on a 5,300 lb payload (20% pin weight) that's a max tow weight of 26.5k.

This is all before you factor in things like cargo, people, a hitch, etc.. If you've got more than a 2wd tradesman model your payload is even lower than that. With something like a Laramie or a Limited, you're probably in the 4,700-4,800 lb payload range (23.5k actual tow capacity). Could even be slightly lower. That's almost 10k lbs less than advertised.

That's still good and plenty of payload to handle most things so don't get me wrong. It's just not what the advertisements say and a lot of people don't realize that. Anything that you change on the truck (such as tires) reduces the payload further. 500 lbs (your numbers) doesn't seem like a lot of payload to lose at 5,300 but if you lost that at 4,700 you're down into the 4,300 lb payload range. If you factor in 500 lbs of cargo, people, a hitch, etc... payload is now in the 3,800 lb range before you even hook a trailer to it.

If you're set on bigger tires, I would at least recommend that you make sure you're running the proper type of tire on the truck. I'd look for a load range E tire for sure. If you intend on changing wheels, make sure they're rated to handle the psi of the tires. Dually tires are capable of running much higher pressures (and you'll need it) for towing larger loads.

Sorry but I disagree and I know my numbers for my exact truck. I’m not just quoting a work sheet, I’m reading my door numbers.

Where you place your load depends the most. I won’t max out a payload before 32k if all the weights at the back of the trailer and it’s lifting the back end up. Obviously you wouldn’t do that but a triple axle trailer would also help this out as you can move weight more forward and backwards to help out. The payload is truck specific and I’m over that weight, 5,367lbs to be exact on a fully loaded Laramie but the towing is the towing, 32,710lbs.

And my numbers at 500lbs was the towing numbers based off of the different gearing, not the payload. The truck will only gain 42lbs in tires. Sure, it’s not apples to apples, a 42lbs truck won’t just drop me to 5,325lbs. I’m sure if I weighed two trucks with different curb weights, the payload wouldn’t be apples to apples but idk, maybe it will. Again I’m not worried about 42lbs.

And yes I understand tire load ratings but it’s almost impossible to buy a 80 aspect ratio tire and not have it be the same load rating as another. This forum and many others have all picked this very popular size. I’m not reinventing the wheel here.

 

[Synolimit]

I wouldn't buy anything but a 4:10. The acceleration from a light or passing is noticeable from a 3:73.

Ok I’ll return it and will look forward to the lower MPG.

 

[nlambert182]

Sorry but I disagree and I know my numbers for my exact truck. I’m not just quoting a work sheet, I’m reading my door numbers.

Where you place your load depends the most. I won’t max out a payload before 32k if all the weights at the back of the trailer and it’s lifting the back end up. Obviously you wouldn’t do that but a triple axle trailer would also help this out as you can move weight more forward and backwards to help out. The payload is truck specific and I’m over that weight, 5,367lbs to be exact on a fully loaded Laramie but the towing is the towing, 32,710lbs.

And my numbers at 500lbs was the towing numbers based off of the different gearing, not the payload. The truck will only gain 42lbs in tires. Sure, it’s not apples to apples, a 42lbs truck won’t just drop me to 5,325lbs. I’m sure if I weighed two trucks with different curb weights, the payload wouldn’t be apples to apples but idk, maybe it will. Again I’m not worried about 42lbs.

And yes I understand tire load ratings but it’s almost impossible to buy a 80 aspect ratio tire and not have it be the same load rating as another. This forum and many others have all picked this very popular size. I’m not reinventing the wheel here.

Well, since you know everything about the diesels and their capacities, good luck sir.

Unless you have the Aisin, you have a max tow capacity on a 3500 ST of 19,680 lbs. If you got the Aisin, then yes you're at 32,710 but again that is on an ST. That is NOT the same on a Laramie. Since it looks like you were reading the Stellantis tow chart since the numbers you use are spot on with that chart (and would not be true on a Laramie) you should also read where it says that Payload and Trailer Weight Rating are mutually exclusive. Just because it says you could theoretically tow 32,710 lbs doesn't mean that you can disregard payload.

Out of curiosity, how many diesels have you owned and what do you typically tow? Serious question... not a poke. There are a lot of factors to consider.

 

[Synolimit]

Well, since you know everything about the diesels and their capacities, good luck sir.

Unless you have the Aisin, you have a max tow capacity on a 3500 ST of 19,680 lbs. If you got the Aisin, then yes you're at 32,710 but again that is on an ST. That is NOT the same on a Laramie. Since it looks like you were reading the Stellantis tow chart since the numbers you use are spot on with that chart (and would not be true on a Laramie) you should also read where it says that Payload and Trailer Weight Rating are mutually exclusive. Just because it says you could theoretically tow 32,710 lbs doesn't mean that you can disregard payload.

Out of curiosity, how many diesels have you owned and what do you typically tow? Serious question... not a poke. There are a lot of factors to consider.

I don’t know everything. Just stating what’s literally printed on my truck and I never said I would disregard payload. If I tow heavy I’ll measure the weights. If I’m over, I’d adjust the weight. Hell you can even add weight to help out. If payloads over and the item is centered but you’re way under on capacity, adding 200lbs at the back of the trailer could take more than 200lbs off the payload but still keep you safe on towing. Or move a 20,000lbs excavator back a foot. Boom, 800lbs less payload.

This is my first diesel. Plenty of towing experience elsewhere. The motor shouldn’t matter, you’re within spec or not. Typical…cars. Then skidsteers, excavator, lifts, scissors lift on occasion.