NGK iridium IX spark plugs OK or is there a better brand? on 2004 Mercury Grand Marquis

Trying to increase gas mileage- local 9-10mpg short hwy. - 13 long (100 miles) hwy.-25!

by in Valley Stream, NY on August 29, 2013
1 answer 1 comment
ANSWER by on August 29, 2013
Use OEM for the best results. Motorcraft fortunately is available at the aftermarket stores like carquest etc...
COMMENT by on August 30, 2013
Thank you,will do.