i got denso iridiums on my 98 accord 2dr, cuz my OEMs went bad, but i still remember what my car felt like in the beginning and after i broke it in, cuz i have low miles on my car, and let me say, i dont kno if they gave me HP difference, but it made my car A lot smoother, makes my shifts feel like water, maybe it can give u a better launch or something, cuz u have better reaction, it indirectly makes ur car faster to the smallest fraction of the degree, i just got it cuz i think they make my car run amazing, my friend got the NGK plantinums on his 98 accord 4dr, and my car is smoother than his even i feel, and we are up to date on all maintenance. whoever said their moving toward iridiums, he's right. my friend on his very modded 5th generation lude(97-01) said his botch's sucked, but just didnt want to pay more at the time for iridiums, but regrets it now. some1 told me plantiums are more expensive but i think he's wrong, the denso from what i saw were the most expensive.