Hw4

My Model X Went In for FSD Repair. The Loaner Was a HW4 Model Y.

FSD v12.6.4 on HW3 vs FSD v14.2.2.5 on HW4, tested on real Vancouver roads.

I didn’t plan this comparison. The service appointment did.

My 2017 Model X 100D (HW3, with a paid MCU2 + HW3 retrofit done years ago) went into Tesla’s Vancouver service center for an intermittent Autopilot dropout — diagnosis: overheating in the self-driving control unit. Tesla replaced the Autopilot ECU (2nd and 3rd gen modules) under warranty. The loaner they handed me was a 2026 Model Y on HW4, and I had it for one day.