Why Miami exposed the flaws of Ferrari’s SF-25: Fred Vasseur’s comments compared with telemetry. Ferrari's SF-25 struggled in Miami, with telemetry exposing major rear-end grip issues.

The Ferrari team principal acts as a spokesperson in front of the media to defend an SF-25 at the mercy of its own flaw—a car currently trapped and unable to express the much-talked-about potential. A speed that, however, must contend with the problems exposed in the Miami Grand Prix, amid a Fred Vasseur trying to save Ferrari and a telemetry that doesn’t lie.

A blanket too short, at times nonexistent
“You always have to make the tyres work within a very narrow window,” Fred Vasseur said at the end of the American weekend. A tyre formula that feels like black magic, as George Russell described it during the 2024 season. Words that carry even more weight after Fred Vasseur’s comment: “Yesterday’s qualifying was by far the worst because we didn’t exploit the tyre potential. Everyone else improved by 5 or 6 tenths when they fitted new tyres, we lost 2 or 3.”

Once the discussion about new tyres was put to rest, Fred Vasseur was asked about the SF-25’s other issue: mechanical grip. A crucial factor in Miami due to the presence of a low-speed section—an area where the Maranello car was losing over 6 tenths to the MCL39, which benefits from a much wider operating window.

From strength to weakness—a dramatic downgrade for Ferrari
Until 2024, Ferrari boasted extreme traction and mechanical grip. Monaco, Baku, and all acceleration zones were the domain of the SF-24, a car that featured the same rear suspension layout. That rear end is now the true weak point of the SF-25, as confirmed by Fred Vasseur at the end of the Miami weekend: “We were off the pace because of the track characteristics. We’re much more limited at the rear, so we tend to align more with McLaren’s approach.”

These words support the analysis we carried out after the first weekend in Melbourne. An intuition now gaining confirmation, as Ferrari’s current technical director, Loic Serra, is working on a new rear suspension with revised kinematics.

Miami telemetry confirms the rear suspension issues
On day 2 of preseason testing in Bahrain, all eyes were on Charles Leclerc’s Ferrari, which clocked a very respectable lap in the morning. The Monegasque driver, in hot conditions and on a slower track, completed a lap in 1:30.8 on the C2 tyre—the “medium” compound later used during the race weekend. After that lap, cameras cut to the Ferrari pit wall, where strategy chief Ravin Jain offered a very telling smile. A benchmark improved on day 2 with a time of 1:29.431.

The SF-25’s potential is there, despite the worse track conditions—hotter asphalt and air—than during the race weekend. With a locked rear end, a measure taken to reduce plank wear, Ferrari “compromised” the front suspension’s performance. This made the SF-25 understeer, even though in Bahrain it had shown excellent corner entry capabilities, comparable to McLaren.

The telemetry comparison—despite different temperature conditions—shows an SF-25 advantage, especially in the slower section 9-10 where mechanical grip matters most. There, the Maranello car, comparing tests to qualifying, shows superior mechanical grip during testing even with a tyre disadvantage. This indicates that the SF-25 was able to operate within its ideal performance window, confirmed also by excellent acceleration and traction values on corner exit.

Ferrari SF-25 telemetry in testing and qualifying conditions – Bahrain

An advantage that, in both Bahrain qualifying and in Miami, was erased by the MCL39, which dominated last weekend. In qualifying, it finished less than a tenth behind pole-sitter Max Verstappen, while in the race the gap was even more telling—with an average speed advantage of over 6 km/h in sector 11-16.

These telemetry data clearly show a car that’s hard to set up, trapped by a locked rear end that stripped the SF-25 of the positives seen in the SF-24. The rear suspension upgrade that Loic Serra has been working on since after Melbourne is underway, but the debut date is still uncertain.

Source: f1ingenerale