I usually change plugs at 30,000 miles, but was wondering if anyone has changed them out at 15,000 miles and noticed better pick-up and gas mileage with the P5. Thanks!
Wouldn't hurt to try since the cost of a set of NGK or Denso regular plugs is only about 3-4 gallons of gas
I'm sure that even with this slightly improved effiency, you can save 3-4 gallons in 15k miles. Not to mention that you'll feel better with fresh plugs in your car