Over the last few months, Ferrari has been caught testing mysterious prototypes based on the LaFerrari. Initially, it looked like Ferrari was testing mules for the LaFerrari's replacement, but it's now believed they were test mules for the new Icona supercar debuting next month.

A successor to the Ferrari SP1 and SP2 Monza, Ferrari's new ultra-exclusive Icona will reportedly be based on the LaFerrari Aperta restyled as a homage to the 1967 Ferrari 330 P4 Le Mans racer. One month before the reveal, Ferrari has been caught testing another LaFerrari prototype.

Video footage shows the matte black LaFerrari cruising the streets. However, this doesn't appear to be a test mule for the new Icona. Ferrari's 330 P4 tribute has already been spied with production parts covered up, but this prototype is uncovered. What could Ferrari be cooking up here?

Compared to the regular LaFerrari, the prototype has several key design changes. There's a new bumper without the central element separating the grilles, while the side air intakes, roof and rear window look different. Whereas the LaFerrari uses center-lock wheels, this test mule has five nuts per wheel. But the most obvious change lies under the hood.

The new Icona is expected to utilize the same naturally-aspirated V12 as the 812 Competizione, but Ferrari could extract more power for the new limited-edition Icona. However, the engine powering the prototype caught on video sounds turbocharged. This coincides with a recent report that Ferrari is working on a new turbocharged V12 to improve performance and efficiency.

Potentially, Ferrari could be testing the new twin-turbo V12 for a future halo hypercar that will replace the LaFerrari. Ferrari typically launches a new halo hypercar every ten years so it could arrive in 2023, ten years after the LaFerrari launched. Alternatively, it could be a test vehicle for Ferrari's new Le Mans racer, but it seems unlikely that Ferrari would test a race car on the road.