Genuine Toyota Part

 -Suits Silvertop and Blacktop.

Ignition components (plugs, cap, rotor, leads/wires) that are significantly worn will result in a noticeable drop in performance along with increased emissions and fuel consumption.  

If you notice a miss-fire that is not fuel related (plugs look tan - not black and sooty or white and free of fuel) you might want to inspect ignition components for excess wear or damage.