[waternchlorine]

Hello everyone, recently I noticed a pronounced drop in my fuel mileage, and while it's nowhere near some of the other horror stories I've read on here, I wanted to explain my situation, and get some advice...

I have a 04 SS with 50k miles on it. Typically driving around mostly highway, I would get 425 miles on a tank. Thought everything was great. I changed oil at 2500-3000 miles intervals and kept the hull clean.

In October, I started noticing my mpg falling from an average of 30 to 27 on the computer. Now I've read in here that the computer doesn't always tell the truth, so I watched the mileage per trip... sure enough, it was dropping.

First thing I thought was a bad oil change... nope. Fuel filter... nope. Air filter... nope. I needed new tires, so I got Michelin Pilot Sport A/S and tried them at 30 psi and 35 psi... nope. Wash and Wax... nope. Brakes are about a year to a year and a half old.

So now, I'm thinking either/both spark plugs and wires, and possibly the O2 sensor might be going bad. After doing some reading in here, if I replace the wires and plugs, I'm going with the Iridium plugs, but I'm not sure what wires to use.

First question, the plugs, etc are suppose to be good until 100k... is this normal to have to change them at 50k?
Second, what wires and plugs are the best for the car? There are 2 Iridiums on the website, the OE Laser and the Iridium IX
Thurd, What about the O2 sensor?


Thanks everyone!