Instead of arguing about "lifetime fluid" in theory, we decided to get evidence. We drained the drive-unit gearbox oil from a Tesla with 100,000 miles on it and sent a sample to a lab for analysis.
What came out of that drive unit didn't look like oil anymore. It was dark, thick with contamination, and carrying the metal wear particles you'd expect from 100,000 miles of gears meshing under load. Fresh Tesla drive-unit fluid, by comparison, is clean and translucent—we filmed the side-by-side so you can see the difference yourself.
The lab analysis confirmed the story: elevated wear metals and degraded fluid condition consistent with extended use without service. This is what "lifetime" means in practice. The fluid did its job for 100,000 miles, and by the end it was spent. No fluid—synthetic or otherwise—survives that duty cycle unchanged.
This is why we offer drive-unit oil service with the correct Tesla-spec fluid and filter: it's a straightforward maintenance job that protects the drive unit, one of the priciest components in the car, for a fraction of replacement cost.
That fluid condition is a matter of opinion. It's a matter of chemistry—and we have the lab report.