Cadillac's 10-part Austrian GP upgrade derailed by electrical failures and floor fire

Cadillac’s most ambitious upgrade of the 2026 Formula 1 season unravelled on Friday at the Austrian Grand Prix, as Sergio Perez and Valtteri Bottas were both struck by separate mechanical failures that severely curtailed the team’s evaluation of a 10-part package fitted to the MAC-26.

Perez triggered a red flag in FP1 and a Virtual Safety Car in FP2, even after mechanics replaced his Electronic Control Unit in full between sessions. Technical director Nick Chester confirmed the root cause remained unresolved heading into the afternoon. “It’s an electrical issue causing the car to cut,” Chester said. “We’re working through it, so we’ve changed some of the components. We’re now working through more components so that we can get ourselves ready for FP3.”

Bottas fared better in the opening session, completing a meaningful run on the new components, but his afternoon ended early when a small fire broke out at the leading edge of the car’s floor. Chester attributed the incident to an assembly error rather than a design flaw. “We had a build issue with the mid-front on his car. So it did let the car down too far,” he explained, adding that the contact was the direct cause of the fire.

The upgrade package itself targets bodywork, floor, diffuser, and rear wing, with the primary goal of reducing tyre degradation — a persistent weakness for the American outfit. Despite the disruption, early data gathered by Bottas in FP1 was described as encouraging, though Chester acknowledged it was too soon to draw firm conclusions.

A decision to hold back a Ferrari power unit upgrade added another layer of frustration, particularly given the high ambient temperatures at Spielberg. Chester said the sheer logistical demand of preparing the aerodynamic package for both cars made a simultaneous engine change impractical. “There’s so much work to bring that upgrade for both cars. Trying to feed in a PU change at the same time would have been too much,” he said, suggesting Silverstone or Spa as possible introduction windows.

With limited mileage banked and key questions about the upgrade’s performance still unanswered, Cadillac faces pressure to extract meaningful data across Saturday’s final practice session before qualifying.