[sliken]

First of all worker 30 hours of labor * factory workforce is a significant fraction of the cost of a car, and not easy to improve.

Additionally a plant that takes 30 hours per car is typically going to have less output than a plant that takes 10 hours per car. Typically each minute during production the car is taking up space, being worked on humans or robots, etc. Additionally efficiencies favor shorter pipelines. Generally a 10 hour pipeline is physically shorter than a 30 hour. Parts, staff, troubleshooting etc is easier on a smaller pipeline. Additionally having each car bridge 4 working shifts for the workers has overheads of it's own compared to 1-2 shifts. Doubly so if you are trying to iterate quickly.

Imagine an assembly line moving at 0.5 mph, for the same physical foot print you could have 3 lines that are 10 hours each instead of a single line that runs for 30 hours. Now imagine there's a issue that shuts down a line for an hour, it's better if it's 1/3rd of your capacity down instead of 100%. If you try an improvement, it's better to put 1/3rd of your production capacity at risk instead of 100%.

[thow-58d4e8b]

For a typical car, only about 10-15% of the manufacturing cost is labor. And that's talking about Toyota Corollas and euro econobox hatchbacks. For a premium electric car, it's probably a single digit

Also, the whole claim would really need a citation, and careful parsing of the methodology. 3x difference in a mature industry like car assembly is very unlikely, and requires a very strong proof to back that statement up.

[sliken]

Tesla gives tours, and frequently discusses optimizations in reduced part counts, design tweaks for manufacturing, etc. I'd think someone with some expertise could tell if Tesla's claims are true.

Some highlights: front 3rd of chassis is one piece, rear 3rd of chassis is one piece, the glass roof is a huge piece and before that's installed things can be installed by robot (steering wheel, dash, seats, etc). Many things are radically simpler, like the interior, dash is basically a aluminum bar the width of the car with an arm for a 15" monitor. Even the ventilation system is simple, few parts, and easy to install. Most cars spend quite a bit of complexity for gauges, displays, buttons, vent controls, temp control, fan control, fans, emergency brake, air valves, etc.

Monroe on youtube (engineer with significant experience, used to work at Ford) took apart an early model 3 and wasn't impressed, didn't recommend it, and called out many details that were expensive, labor intensive, etc. He did a new model 3 and model Y and left quite impressed. Many innovative changes to make things easier to produce, cheap to reduce, reduced parts counts, etc. Monroe claims tesla is iterating their production faster than anyone else he's looked at, and he's looked at a very wide variety of cars (and other products for that matter).

Monroe also reviewed the VW ID.4 and left quite under impressed. Ironically he didn't expect much from the Ford Mach E, but was very pleasantly surprised to see innovative engineering, impressive design, and overall was quite impressed. Although he was horrified by the complexity of the cooling system and has serious doubts about it's long term reliability.

[rcMgD2BwE72F]

The proof? VW CEO statement.

The 10% difference pays the next factory.

[HWR_14]

30 hours does not necessarily mean 30 man hours. And part of the difference seems to be that parts are assembled before they get to the line with Teslas (the front and rear 1/3's) , so it could be that they have the same labor costs baked in there.

Meanwhile, I assume that space is the cheapest part of the car factory, dwarfed by robotics.

I mean, the VW is cheaper than the 3, so that implies they aren't spending that much more.