When I took the factory tour in early 2013, the guide did not let us go near the area where they build the battery but he explicitly told us:
The battery weighs the same for 60kWh and 85kWh. Dead cells are put into the 60kWh battery in order to keep the weight the same. This odd feature is to avoid performing two sets of crash tests.
They also listed only one weight in any of their documentation in the past.
Recently folks have been commenting on the fact that the 60 battery version weighs less. Now with the 5.9 version of the manual, Tesla lists different weights for the 60 and the 85.
The curb weight is the weight of the car parked with standard equipment and without any occupants or luggage. The difference in the weight of the 60 vs the 85 is 223 pounds or 101 kilograms. Both bare bones versions have the same options except the 85 is “supercharger enabled” but this is simply a software switch that 60 owners can purchase after the fact.
The gross vehicle weight rating is 5,710 lbs or 2,590 kg for the Model S. This second measure is how much weight is safe for travel including any additional car options, passengers and all cargo. For a 85 battery, you can carry passengers and cargo up to 1,080 pounds; truck manufacturers use the term payload for this difference. This number is actually smaller then I would expect. I can easily imagine a scenario in the United States where four people were traveling and each weighted 200 pounds and were also carrying some particularly heavy items in the trunk and frunk. They could exceed the Gross Vehicle Weight Rating. I don’t think this difference between Curb Weight and Gross Vehicle Weight is much different than for ICE cars but finding these specification is not that easy. The payload for a Dodge Ram 1500 Express is 1,719 pounds.