Tires size changing tow capacity

[Merk44]

I'm thinking of putting larger tires on my truck and heard it will affect tow capacity. Now first off, I'm no where near capacity or load limit of the truck but thinking ahead if we end up with a lager RV. I found a calculator to shows a decrease of 15 revs/mile. Anyone have an idea how this will affect towing?

[NB Canada]

Can’t imagine how it would affect tow capacity
Could easily affect handling though

[Merk44]

Can’t imagine how it would affect tow capacity
Could easily affect handling though

I've read info that less rev/mile will decrease tow capacity because truck is working harder. Now is that true or not what I'm trying to figure out. Obviously I'm not going to a monster truck tire so more curious than anything.

[Crazybanshee]

Putting a taller tire on will raise the gear ratio of the truck making the engine pull harder off the line and on hills.

[Merk44]

Putting a taller tire on will raise the gear ratio of the truck making the engine pull harder off the line and on hills.

Does it affect tow capacity?

[Crazybanshee]

I would guess it affects tow capacity that is why a truck with 4.10 gear ratio usually has a higher tow rating than a truck with 3.73 ratio

[Hoopy Frood]

Putting a taller tire on will raise the gear ratio of the truck making the engine pull harder off the line and on hills.

I think you have it backwards, a taller tire is like lowering the gear ratio, i.e. like going from 4.10 to 3.73. It has occurred to me that this statement is imprecise. A taller tire will result in taller gearing, lower numerically, example 3.73. Lower geared vehicles will have higher ratios, numerically speaking, example, 4.10.

[Stealth13777]

Yeah, right idea here, but bigger tire is basically going to reduce torque multiplication, meaning less pull off the line. I don’t see your truck details but that would help tell part of the story, and you could determine exactly the change. What you have in the initial post isn’t significant.

Other things are tire weight, load rating, inflation pressure. Biggest one I would look at is the load rating on new tire versus factory tire. A lot of people make a mistake on 2500/3500 trucks going big but not buying enough tire.

[Merk44]

Yeah, right idea here, but bigger tire is basically going to reduce torque multiplication, meaning less pull off the line. I don’t see your truck details but that would help tell part of the story, and you could determine exactly the change. What you have in the initial post isn’t significant.

Other things are tire weight, load rating, inflation pressure. Biggest one I would look at is the load rating on new tire versus factory tire. A lot of people make a mistake on 2500/3500 trucks going big but not buying enough tire.

I have a 2024 GMC Sierra 2500HD AT4 arriving in the next week so don't have door jam info. I have the duramax 6.6 and GMC states the gear is 3.42. As for tires I'm considering, they have a load rating E. Hope this helps a bit but assume without door jam info it's limited. The 2024s are redesign and just being released so limited info so far.

[huntindog]

Can’t imagine how it would affect tow capacity
Could easily affect handling though

It will absolutely affect tow capacity. Every trucks rating is based upon it's weakest part. Just what that part is, and how much it affects it is a secret. The manufacturers
engineers do not share this info. sometimes it is pretty obvious. Other times not...and it sometimes gets hotly debated on some forums.