To grill a rib eye roast, set up the grill in a manner that allows for allowing optional smoking flavor and with a high heat and cooler area that allows you to sear the roast quickly on all sides to seal in the flavors. The roast should be grilled 15 minutes per pound depending on the degree of doneness desired.
To add a smoky flavor, soak wood chunks in cold water for an hour and wood chips for about 15 minutes. Cover packets in tin foil and poke holes in the foil so the smoke can escape while grilling. After lighting the charcoal briquettes, allow them to burn until covered by a thin layer of ash. To create two areas of heat, move briquettes to one side, stacking them two or three high. Open grill vents, and let the grill heat for five minutes. Rub the roast with vegetable oil, and season with rub or salt and pepper before grilling.
Sear roast on the high-heat end of the grill for two to three minutes on each side, then move to the low-heat side and grill for 30 to 60 minutes. For a rare roast, an instant-read thermometer should read 125 to 130 degrees Fahrenheit after the roast has rested for 20 minutes. Note, the temperature is higher for other doneness levels, and resting a roast after removing from the grill increases the internal temperature by 10 degrees, a phenomenon called carry-over cooking.