[N106FM]

Originally Posted by Benacio

I currently own a 2006.5 Optima with the 2.4L. I have managed to shave about 3+ seconds off my 0-60 time by simply replacing the stock plugs with some Premium Denso Irridium Plugs (IK15)(5303) which run about $13 a piece at Autozone but are well worth it. I attribute this major change in performance due to the fact that the oem plugs actually detune the engine substantially(probably for warranty reasons) the electrode in the oem plugs is very thick, like a heavy duty truck (.75-.85mm) plug which is good for plug life but not good for performance, since the thicker the electrode the greater the resistance. The premium plugs on the other hand have a .04mm eclectrode which is thinner than a mechanical pencil lead and offers very little resistance thus creating a much bigger spark. Also the quality of gas used also makes a difference, I use mostly Chevron gas and occasionally Conoco or Shell Gas, I stay away from cheap gas brands, I made the mistake of using Circle K gas and my car ran like crap for a week and half or one and a half tank fulls of gas, I used some Lucas Fuel Treatment which helped out a lot. I am still waiting for a K&N air filter to become available, I tried installing a cold air intake but the results were trivial and the noise was kind of embarassing, I have plans to install a longer air intake and run it around the engine along the firewall towards the passenger side, using some thick 4" PVC piping I picked up at ACE Hardware, I hoping the noise will filter out by the time it gets to the air filter. I hope this info helps and I hope to hear other peoples Ideas.

Did the plug do anything for the gas mileage?

Mike