In a small bowl, mix together chili powder, salt, ginger, thyme, and black pepper. Rub spice mix into pork tenderloins. Place meat in a baking dish, cover, and refrigerator for 2 to 3 hours.
Preheat grill for medium heat.
Brush oil onto grill grate, and arrange meat on grill. Cook for 30 minutes, or to desired doneness, turning to cook evenly.