Add oil, brown sugar and spice rub to a plate. Use a fork to combine.
Press each side of Pork into the seasoning mixture to evenly coat the roast.
Place the roast directly on the grate of your smoker. Smoke for 4 hours.
Remove from smoker and wrap in foil, and let rest for at least 30 minutes before slicing to serve. NOTE: For the best result be sure to cut against the grain and use a meat slicer.