No the 40,000 miles really is for replacement. That being said it does sound pretty low and it is for their fancy dual clutch direct shift transmission. But sea

No the 40,000 miles really is for replacement. That being said it does sound pretty low and it is for their fancy dual clutch direct shift transmission. But sealed transmissions with "lifetime" fluid wear out faster than a decent transmission. There isn't some major transmission improvement that allows for a sealed transmission, it's just a regular transmission that you can't perform maintenance on. As for whether or not it's strictly necessary, you can avoid oil changes altogether and a decent car will make it quite a long way before it seizes up. https://www.reddit.com/r/Justrolledintotheshop/comments/2zochr/audi_tt_with_84000_miles_without_an_oil_change/ https://www.reddit.com/r/Justrolledintotheshop/comments/2zoc... You can do the same with a transmission or a differential, but they'll last a lot longer if you replace the contaminated and worn out fluid with new fluid. But even just checking the fluid level in a transmission or differential, if the fluid is low, you can't ever just refill it. It didn't burn up, you've got a leak and it'll probably just get worse if you ignore it. There are plenty of vehicles out there with absolutely ludicrous mileage on them, on a modern vehicle, if you keep on top of maintenance, engines and transmissions can last hundreds of thousands of miles. As for suspension components on a Tesla though, I would expect to spend a decent bit keeping all of them in working order. The suspension on a Tesla is really nice, but air suspension isn't nearly as robust as a simpler Macpherson strut setup on an econobox. It's fancy, but fancy suspension and more moving parts means more things to wear out and fail. You've got 2x the ball joints to fail in the front, additional linkages all over, and more bushings to wear out.