1. Pat the pork tenderloins with paper towels to dry and trim off the silver skin. Combine the spices, sugar, and salt, and liberally rub the mixture all over the meat.  Leave to sit for an hour.
2. Light up a gas grill and turn the burner at one side to medium-high. Reduce the burner at the other side to low. These settings will create your two-zone cooking area.
3. Place the pork tenderloin over the high-heat zone (direct heat) and cover. Cook for 5 to7 minutes, flip and cook the other side for another 5 to 7 minutes.
4. Move the pork tenderloin to the low-heat zone (indirect heat), and cover to cook for another 3 to 4 minutes. Check the internal temperature for doneness and set it down when the thermometer reads 140 to 145°F.
5. Tent the pork tenderloin in aluminum and leave it to rest for 10 minutes, so the juices redistribute. Slice into thin pieces in a crosswise manner to serve.

You can also check out this video recipe for more tips.