Place pork in a large resealable plastic bag. Mix together soy sauce, sugar, sesame oil, peanut butter, garlic, curry powder, ginger, and salt in a bowl until smooth. Pour marinade over tenderloins, press air out of bag, seal, and refrigerate overnight.
Preheat an outdoor grill for high heat.
Use a paper towel to pat any excess marinade from the pork; allow to sit at room temperature while the grill is heating. Lightly oil grill grate. Cook pork 3 minutes on each side (on all four sides) for a total of 12 to 15 minutes. The pork will be done when it is no longer pink inside and has reached an internal temperature of 145 degrees F (65 degrees C). Remove from the grill and cover meat loosely with a foil tent. Let rest 5 minutes before serving.
