2007 corolla 44 mpg 5-speed

[digitalness]

OK well the best way to save gas is to drive slower, however as of late i have seemed to max out my gas mileage (I CANT DRIVE ANY SLOWER, im not an *** either ;( ).. i cant really do anything else to better my records of 39.5 city and 44mpg US hwy.... i have created additional ground to frame, and disabled daytime running lamps and never go over 2500k rpm...

my question is can anyone reccomend plug wires (bosch type) or even a better spark plug that works with a 2007 corolla? or is that not a good idea seeing as though these cars come with iridium type...

thanks