Kind of an interesting video too. Starts around 1:30 and goes into all the issues they have.
https://www.youtube.com/watch?v=q5HgthPgzgQ
https://www.youtube.com/watch?v=q5HgthPgzgQ
Now, granted, dyno-testing a Tesla is a little different from a conventional car. As Brooks explains, an electric motor's all-the-torque-at-zero-RPM power delivery can wreak havoc on a dyno, since this equipment was designed to work with internal combustion engines that have to build up revs to hit peak power. As we saw back when Brooks dynoed his P85D, the Tesla's instant torque delivery meant the car had traction issues, squealing its tires on the dyno's rollers and making it tough to get an accurate reading.
So let's cut to the chase: 588 horsepower and 920 lb-ft of torque at the wheels, in a bone-stock Tesla Model S P100D with Ludicrous+. But that might not be the final word: As Brooks explains, these dyno runs started from a roll, not a dead stop, due to the traction issues we mentioned above. Even then, the car briefly spun its wheels on the dyno rollers, meaning it momentarily made more power than the dyno could handle. Finally, these numbers came from the ninth consecutive dyno pull—meaning the car's battery wasn't at full charge.
In other words, the P100D might actually make even more power than those numbers Brooks recorded.