With Juventus president Andrea Agnelli and Exor president and Ferrari chairman John Elkann, the 36-year-old flew to Maranello by helicopter.
Exor is the Agnelli family's investment firm, which owns both Juventus and Ferrari.
Ronaldo purchased a red Ferrari Monza SP1 priced at $1.95 million and only available by invitation, according to the Italian newspaper Corriere Della Sera. Zlatan Ibrahimovic, who played for AC Milan in their weekend thrashing of Juventus, is among those invited to purchase the car.
During his visit to the Ferrari factory, Ronaldo posed for photographs with Ferrari Formula One drivers Charles Leclerc and Carlos Sainz, who each received a signed shirt bearing Ronaldo's name and number.
Juventus was defeated 3-0 by Milan at the Allianz Stadium on Sunday.
Brahim Diaz, Ante Rebic, and Fikayo Tomori, who is on loan from Chelsea, scored the visitors' three goals, lifting them to third place in Serie A and dropping Juventus to fifth.
On Wednesday, Juventus takes on Sassuolo, but it is uncertain if Ronaldo will play.
On Tuesday, Pirlo told the club's website, "Cristiano has played several games this year and has scored a lot." "Today we'll make a decision; tomorrow is a crucial match, and I'm hoping to have everyone available."