The four-cylinder Ford Mustang S560 Ecoboost Coupe offers significant improvements over the previous model but struggles to overcome the enduring appeal of its V8 sibling.

As sales of sport-utility vehicles have exploded in the Nineties, buyers for two-seat and two-plus-two coupes have become scarce. Witness the sad demise of the Mazda RX-7, the Nissan 300ZX, and the ...