Floyd Mayweather's pricey car collection took a massive hit this week -- when a trailer transporting Floyd's Bentley and 2 Rolls Royce whips burned down to the ground ... TMZ Sports has learned.
We're told the truck was transporting Floyd's rides from Vegas to Miami when something went wrong just outside of Phoenix, Arizona on October 7th at 1:31 AM ... and the entire unit went up in flames.
You can see in the pics, the cars were burnt to a crisp -- including one of Floyd's custom Jeeps.
It's unclear how the fire started -- but Arizona State Troopers confirm the incident and say there were no injuries reported.
TMZ Sports contacted the transportation company and confirmed the cars were shipped through Obi Okeke at Luxury Fusion Motors -- Floyd's longtime car guy.
We reached out to Floyd and Okeke -- no comment from either one.