Does the frequency that you have to change plugs change with F/I cars compared to N/A or is still the same? I've gotten into the routine to change my plugs every other oil change (6000 miles). When I decide to go F/I I wonder if it will be good to change them every oil change (3000) miles. Plugs are really cheap so its not a big expense or task to do.

 

Man you need to shift the decimal there! 6,000 miles is waaaaaay short for a spark plug change interval. My wife's truck with a GM 4.5L V6 has no-sh!t 100,000 mile plugs on there. I pulled them at 65k because I was worried about the long service life they'd had because I usually shoot for 40k miles. They looked brand-spanking new.



It's a good thing, too, because half the engine is buried under the cowl.