Combine cumin, chili powder, garlic powder and salt in a bowl. Rub spice mixture all over the pork tenderloin. Cover and refrigerate for 2 hours.
Preheat oven to 350 degrees.
Place tenderloin in a baking dish. Squeeze the juice of 1/2 the lime on the pork tenderloin. Cut the remaining half of the lime and lay around the pork. Drizzle the pork with olive oil. Bake for 60 minutes or until internal temperature of the tenderloin reaches 160 degrees. Remove from oven and let rest for 10 minutes. Slice and serve.