Why Leclerc isn't using latest Ferrari ADUO2 engine in the Spanish GP

Charles Leclerc is still feeling the pain of smiting the wall at the exit of the Parabolica in last weekend's Italian Grand Prix, and the result of the crash is that he will not be able to use Ferrari's latest Formula 1 engine spec during the Spanish GP.

It's understood Ferrari engineers deemed the 067/6 unit, fitted with the second package of modifications permitted by the FIA, to be sound, but they did not want to take the risk of running it at the Madring.

The reason is very simple: F1 regulations prohibit running an engine that cannot be worked on in all of its many homologated components. No cracks or breakages were found during the external structural checks, but the intention is to carry out more thorough X-ray examinations to determine whether there are any small areas of damage that may have gone undetected.

The decision not to risk the ADUO2 engine in the Spanish capital is therefore a logical one: the Madring circuit is new and the drivers need to run for as long as possible, while the engineers need to gather data in order to finalise a set-up that will have to be a significant compromise to combine the demands of very slow sections with those of the fast ones.

The Iberian capital, incidentally, is located 667 metres above sea level, an altitude similar to that of the Red Bull Ring in Austria. So the more substantial turbo compressor fitted as part of the ADUO2 package could have provided a performance gain in the slightly thinner air.

Any small issues with the power unit during Friday practice could have risked compromising the preparation for the GP, hence the decision to postpone the return of the engine under observation until FP1 in Baku.

Leclerc's car was badly damaged by Monza crash and the engine's structure is still being thoroughly checked

Leclerc, therefore, will have an ADUO1 engine at his disposal, while the trackside staff will be able to assess the actual performance difference between this unit and ADUO2, which Lewis Hamilton will be able to use as normal.

After the disappointment at Monza, Ferrari is quietly hopeful of performing well in Madrid. The track could suit the characteristics of the SF-26: a medium-to-high level of aerodynamic downforce is required, and the asphalt is not expected to provide a particularly high level of grip, which could favour those with excellent traction on corner exit.

Downforce should matter more than efficiency (we may see the additional flaps on the actuators of the movable wings reappear), and the Ferrari should be less affected by the power deficit to the Mercedes V6 because there are 22 corners and the opportunities to recharge the battery are considerably greater than at Monza.

Hamilton and Leclerc will need to focus heavily on single-lap pace, because a strong qualifying performance on a circuit where overtaking will be almost impossible could prove decisive.

If things do not go according to plan, however, it would not be out of the question for the Monegasque to put a second engine into service with ADUO2 (available in the pool), taking his first penalty for introducing a fifth power unit of the season, but ensuring that he has enough of a reserve to finish the championship without any further surprises.