i have a '99 GP GT, 4-door and bone stock, i bought it used and its about time to replace the plugs and wires, so i was just wondering if the "Performance Iridium 4" plugs actually give any kind of power increase/ mpg increase or if they just say that to get more money

also thinking of a K&N air filter just for fun but i want to know if their worth the money

P.S. - im trying to beat this tool at work with an Integra who just barely beats me from a 20 roll so any advise is greatly appreaciated