What is the fastest car in Forza Horizon 5 when fully tuned?

The title of the fastest car in Forza Horizon 5 can vary depending on specific tuning setups and how one defines "fastest," whether by top speed or acceleration. However, when fully tuned for maximum speed, the Bugatti Chiron often emerges as a top contender due to its incredible horsepower and aerodynamic design which enables it to achieve astonishing top speeds. Players who meticulously tune and adjust the Chiron's settings can potentially surpass the competition in terms of raw speed, although in-game updates or individual tuning discoveries could shift this ranking. It's also worth acknowledging that cars like the Koenigsegg Jesko and others are also in the running for the fastest status after extensive modifications.