Artificial Intelligence1 min read

Post-training 4B model with RL to fly Tesla Roadster 21% better than GPT-6 Astra

By · Published by Everything Blog

In short

Researchers built an open-source simulation where models pilot a 2,000-kilogram vehicle using cold-gas thrusters to execute stunts in winds reaching 33 meters per second. Frontier models completely failed real-time kickflip landings over a Cybertruck because their decision speeds of one to six seconds missed the required 0.2-second control window. After receiving a thirteen-dollar reinforcement learning post-training run, Qwen3-4B reached a 0.09-second reaction time. This allowed the compact model to achieve a 90% real-time landing rate on a 14-meter road.

Key points

  • Massive general-purpose models cannot handle dynamic aerial navigation when their inferen…: Massive general-purpose models cannot handle dynamic aerial navigation when their inference latency exceeds the 0.2-second operational threshold.
  • Small four-billion-parameter models can be specialized cheaply to dramatically surpass fr…: Small four-billion-parameter models can be specialized cheaply to dramatically surpass frontier architectures in real-time physical control.
  • Removing latency constraints allowed paused systems like DeepSeek to land 87% of stunts,…: Removing latency constraints allowed paused systems like DeepSeek to land 87% of stunts, proving computational speed was the primary failure point.

Sources checked by our analysis pipeline: 1

Last Thursday (October 15), Tesla's new Roadster drove off a ramp that curled over until the car was upside down, rolled upright in the air and landed. It then used thrusters to hop over a Cybertruck. Turns out the future does have flying cars.

The demo had already been pushed back two weeks, "due to high winds" (Elon Musk on X). That made us wonder: with a language model in the pilot's seat, how would the car do in that wind?

We built an RL environment around a physics simulator of a flying roadster to find out, handed the controls to LLMs, and turned the wind up. We let some of the latest best models fly it: DeepSeek V4.1 Flash, Meta's Muse Spark Open, Reflection's Beam 1.0, NVIDIA's Nemotron 3.5 Super VL, TypeSafe's Jev 1.14, and even OpenAI's GPT-6 Astra.

Asked for decisions in real time, these models crashed almost every flight: most take 1 to 6 s to answer, and the car needs a new action every 0.2 s. When we paused the world so the models could think…

Artificial Intelligence