How much does the Model 3 Performance actually weigh?

[vogz]

NO, E= mc^2 has nothing to do with energy magically becoming mass. That happens ONLY in nuclear reactions. Please believe me, I have proper training to tell you that. It seems a lot of people in forums are genuinely confused about it. And holy cow, you must not use relativistic mass when talking about not-so-free electrons in batteries. PLUS, the Li-Ion batteries work because of motion of IONS, not electrons!

Ok great. It's not really that big of a deal as far as the actual weight of our cars goes either way. Take it up with the "Physicist" who posted it. I just pulled it from a Physics board.

EDIT: Apparently this guy talked to some Physicists about it and they agreed.

This thread seems to refute your assertions too.
https://www.reddit.com/r/askscience/comments/2k1zov/is_a_fully_charged_battery_heavier_than_a_dead/

 

[P3D-R]

This was after I installed my coilovers but I'd say that's somewhat negligible. 4033lbs. The coils might be about 20lbs lighter in total. Second pic is with me in the car and the corner weights got even better. lol. I didn't even corner balance. This is just set to even ride height. I was so ecstatic I said screw it. I'm not gonna adjust the height to make it perfect. I can live with ~3% cross until my skills require more accuracy. TBH I gained another 15lbs since CV-19 so it might have helped now. LOL.

 

[alexgr]

Ok great. It's not really that big of a deal as far as the actual weight of our cars goes either way. Take it up with the "Physicist" who posted it. I just pulled it from a Physics board.

EDIT: Apparently this guy talked to some Physicists about it and they agreed.

This thread seems to refute your assertions too.
https://www.reddit.com/r/askscience/comments/2k1zov/is_a_fully_charged_battery_heavier_than_a_dead/

Well, one can argue the energy stored in a chemical cell is stored by means of changing the electric field since the kinetic energy of particles is not changing. So, one can say the energy in a Tesla battery is stored in the form of energy, not in the form of mass meaning there no energy-mass transformation happening.... Also, technically, there is a concept of thermodynamic limit that basically argues that the states of a system other than the equilibrium state have an immeasurable probability. I think this applies here pretty well. Also, if you try to stretch the relativistic theory to the motion of charges then the mass of Tesla will increase with the increased speed of electrons in the electrical systems during acceleration. So, the faster you go, the heavier you are.

 

[JCtx]

So 5lbs per wheel and tire package from 20" to 18".
The battery is not heavier - more energy dense cells does not equal more weight.

Somebody weighed both, and it was 10 lbs difference. Did you actually weigh them yourself? The 20" wheels have a lot more spokes, and they're not forged as far as I know, so 10 lbs sounds about right to me.
And the battery comment makes no sense. Going to an extreme, a battery pack of 10 kWh is not going to be the size of a 80kWh one, so the more energy density (with the same chemistry and technology), the bigger the pack has to be. Unless Tesla is underrating the 78kWh battery pack, the more energy a pack has, the bigger it has to be.

 

[MasterC17]

Somebody weighed both, and it was 10 lbs difference. Did you actually weigh them yourself? The 20" wheels have a lot more spokes, and they're not forged as far as I know, so 10 lbs sounds about right to me.
And the battery comment makes no sense. Going to an extreme, a battery pack of 10 kWh is not going to be the size of a 80kWh one, so the more energy density (with the same chemistry and technology), the bigger the pack has to be. Unless Tesla is underrating the 78kWh battery pack, the more energy a pack has, the bigger it has to be.

I have 9 sets of different tires and wheels for the Model 3, and a spreadsheet of weights from many Model 3 components. In general, a bigger wheel is heavier, but the tire is lighter all else being equal. In this case, the 20" Wheel and Tire Package (2018-2020) was 53.6lbs, and the 2021 is 54.5lbs. The 18" Wheel and Tire Package is 49lbs.

The definition of battery cell energy density is the measure of how much energy a battery contains in proportion to its weight. When we talk about increased battery energy density, it is in relation to the amount of energy that can be stored in the same amount of weight. Therefore, if the energy density increases, the weight does not change. The size of the Model 3 pack is constrained physically by space. They didn't add cells to increase the kWh capacity, they increased the energy density of each cell by a small amount through improved chemistry. Battery density has almost tripled in the last 10 years, and will continue to improve. In fact, one of the main points of Battery Day was highlighting increasing energy density while maintaining/reducing weight.

I am quite certain the Performance is negligibly (25lbs or less) or not at all heavier than the LR AWD.