so i finally changed my sparkplugs today. its on a 02 4.7 with 113000 miles the old plugs i pulled i decided to check the gap and they were at .067-.070 when they are supposed to be .040. surprisingly the truck was running pretty decent. but wow new plugs and a k&n filter and i can definately tell a big difference.

 

Funny how those little things effect performance. You will probably see an extra mpg too!

 

yah when i first picked up the truck i had about a 5hr drive all highway to get back home. (i know there no 100% accurate) the fuel mileage gauge was reading about 17.5 mpg and tonight on the drive home it was reading about 20mpg at a constant 70mph

 

Yeah i changed my plugs at 95,000 miles and i picked up 4mpg on my freeway drives.