I have an 04 Sebring Sedan I4-DOHC (X) that just hit 75,000 miles. I replaced the spark plugs with Autolite XP Iridium spark plugs because I thought "Hey, what a few dollars more for another 75,000 miles?". The problem is, after changing the plugs and wires, my fuel economy DECREASED from about 24 combined to less than 22 combined. The guy at the Auto Parts store said I need to increase the gap from the stock .05 to .06 because iridium fires differently than platinum. Is that true? Why would my Fuel Economy go down?

 

because u need to put regular copper champion plugs in there thats it.

 

Autolites are for fords!!

 

OEM spark plugs are always the best way to go if you want OEM performance. Only change style or brand if you have need to change that.

 

You have just discovered that your Chrysler will run best on the Champions it was designed for.