From a design point of view, what limits the slate to 1000 pounds towing capacity

[Trace26]

The issue that I have with the 1000# towing limit is that most single axle utility trailers need 2000# capability. Many unibody vehicles can tow that, so why can't this? I don't think it's unreasonable to expect to be able to get a single scoop of mulch on a utility trailer.

They don't need 2000lbs capacity to pull a 2k trailer. You can get an aluminum 2k trailer that's about 300lbs. Then you would be limited to 700lbs on the trailer if you want to stay within the tow rating of the truck.
We have a 16k trailer we pull with a truck with a 10,000lbs tow rating. You just keep the trailer + load under the rating. If you want to that is, we have towed upwards of 12,000lbs on several occasions.

 

[AZFox]

The issue that I have with the 1000# towing limit is that most single axle utility trailers need 2000# capability. Many unibody vehicles can tow that, so why can't this?

It's because the Truck is designed to be affordable, and doubling the towing capacity would add cost.

 

[danielt1263]

Fortunately for me, my trailer is only 600# (including the boat.)

But yea, maybe the confusion here is trailer capacity vs trailer weight. U-Haul's 4' x 7' utility trailer weighs 630# when empty...

 

[RedJoker]

Ok, maybe I shoul

It's because the Truck is designed to be affordable, and doubling the towing capacity would add cost.

I think that's the point of the original post. What would be the additional cost to increase the capacity? Are we talking $50 or $5000 to double the capacity?

 

[AZFox]

I think that's the point of the original post. What would be the additional cost to increase the capacity? Are we talking $50 or $5000 to double the capacity?

The original question is "When we talk about payload and towing, what is the limiting factor?" and suggests that it could be axles, battery, motor, etc...

The limiting factor is cost.
Or maybe cost is a meta-factor, if you will.
@atreis eloquently worded it this way:

It's a choice, and then Engineering around that choice, so likely not any single component at this point that limits [towing capacity] to 1K lbs.

So a follow-on question would be

How much more would it cost and what changes to the design would be required for the Truck to have heavier payload and towing capacities?​

 

[KevinRS]

It is probably going to be a combo of things. As is, it may well be possible, and some people will tow 2k lb trailers, but that will be outside the safety margin, could result in criminal liability if something goes wrong, and even if it doesn't, could damage the truck.
To do it right, you might need to change out the axle, suspension, and reinforce the frame/body, and upgrade the brakes, and even then, you might have problems with lack of power, and be unable to climb a hill, or unable to get up to full speed, or have battery life terribly short or system shut down due to overheating. No one's going to know what is possible or what to upgrade until people have the trucks, and some of the components on the prototypes we've seen pictures of aren't going to be the same as the final product.