Mercedes found power unit software glitch only after Russell's Belgian GP retirement

A software fault buried in Mercedes' 2026 power unit calibration distorted George Russell's energy management — how and when battery power is deployed — for multiple races. Russell adapted his driving to compensate. Mercedes identified the root cause only after his Spa DNF on 19 July. He called the new units "exceptionally complex," the problem "almost impossible to see." Hungary offers the first test of the fix.