The crash was reported at 8:14 p.m. on Porter Road at Woods Road.
The man killed was identified as Philip R. Hastings of Bear.
Hastings was eastbound when a 2004 Toyota Camry made a left turn from Woods Road, pulling into the path of his 2014 BMW S10.
The front of the bike struck the left rear side of the car, police said, and Hastings was ejected, landing on the south edge of Porter Road. The Toyota spun and came to a stop in the roadway.
Hastings, who was wearing a helmet, was treated by New Castle County paramedics and taken by ambulance to Christiana Hospital, where he was pronounced dead.
The driver of the car, Elena J. Kirk, 58, of Bear, suffered minor injuries but declined treatment at the scene, police said.
Police said they are still investigating the crash.
Porter Road was closed about three hours.