Among the many advantages presented by the 4680-type cylindrical cells is the fact they enable a lower vehicle weight in combination with the structural battery pack—at least that's the theory of it.
While Tesla did not disclose any numbers in that regard, the weight difference between a Model Y fitted with 4680 cells and a Model Y packing 2170 cells should probably be significant. Well, that doesn't seem to be the case in real life.
Ryan Levenson from The Kilowatts had the opportunity to compare an Austin-made Model Y with the 4680 cells and structural pack with a Fremont-made Model Y with the 2170 cells. He uploaded a video on YouTube which goes into great detail about the differences between the two vehicles, but after many viewers asked about the weight difference, he put both vehicles on the scales.
This revealed a negligible weight difference of 20 pounds (9 kilograms) in favor of the 4680 Model Y. Before you ask, yes, the Austin-made Tesla Model Y was indeed fitted with the 4680 cells and structural pack.
The video notes that the vehicle is a Model Y Dual Motor (Standard Range) that offers 280 miles (450 kilometers) of range and starts at $61,990. The California-made car is a Model Y Dual Motor Long Range with a 330-mile (531-kilometer) range and $65,990 starting price.
The Texas-made Model Y tipped the scales at 4,480 pounds (2,032 kg), while the California-made vehicle weighed 4,500 pounds (2,041 kg).
So, why isn't the 4680 car much more lighter than the 2170 car? There's no official answer on this.
We know that Elon Musk recently said the structural battery pack is "far from optimized," and the insignificant weight advantage of the 4680 Model Y has over the 2170 Model Y shows it.
In the Twitter thread started by The Kilowatts, several people speculate that the castings might be heavier than originally designed, offsetting the weight-saving brought by the structural pack. There's no way to tell if that's the case unless someone manages to weigh the cars and the battery packs separately.
Earlier this month, Munro & Associates dismantled a Tesla Model Y's structural pack and weighed it, finding that it tips the scales at 1,198 pounds (543 kilograms)—including the attached seats and center console.