NGK Iridium Spark Plugs SET of four, 08-09 Caliber SRT-4

Review star icon Review star icon Review star icon Review star icon Review star icon
Model Number: 221263

These spark plugs are the most popular, and best spark plug available for the 08-09 Caliber SRT-4.

If you have over 25-30,000 miles on your spark plugs, or if you have increased the boost on your Caliber SRT-4, then its time to change your spark plugs.

NGK Iridium plugs are the BEST plug we have ever tested in turbocharged cars. These plugs improve acceleration, eliminate stumbling under boost, create a smoother idle over worn plugs, and can withstand high temperatures from turbo engines.

These spark plugs come with a gap of .035-.038 thousandths, however, the recommended gap is .032, so the gap on these plugs must be checked/reduced before being installed.


  • Fine Iridium Tip Has High Durability and a Extremely Stable Spark
  • Extremely High Melting Point
  • Trivalent Metal Plating
  • Superior Anti-Corrosion and Anti-Seizing Properties
  • Outstanding Acceleration, High Fuel Efficiency and Durability
  • Ultimate Design, Technology and Performance
  • Note: This listing is for a set of four spark plugs. Quantity of 1 means a set of four plugs.

    NGK Iridium Spark Plugs SET of four, 08-09 Caliber SRT-4, Ignition & Electrical: Store Name

    Ask a Product Question

    • Tim
      Hey, still learning bout the csrt4 and this is my first turbo car, so id rather ask stupid questions than mess up or break hard parts. I have an 08 csrt4 with a lower eng mount, mpx bop, drop in aem filter, and a side exit muffler delete. I drive my car hard from time to time but it is my A to B. Looking for ur opinion on stock or 1 step colder ngk iridiums? Also an opinion on plug gap? I'm still running stock boost and i've heard everything from .32, .35, .38, and .40! Thoughts? Thanks
      2 Answers
      • Modern Performance

        Anytime you are running higher boost, and or driving the car hard you should use one range colder. We recommend anywhere .35-.38 gap for factory turbo cars with 15+ psi boost.
      • Armon

        stock boost .35 gap, if your running stock boost and plan on upgrades just buy the -1 heat range and save yourself the trouble.
    • Kyle Cota
      Are your NGK one step colder Iridium Spark Plugs come all four for 30 or are they 30 a piece
      1 Answer
      • Customer Service Rep

        This is a set of four spark plugs, just as shown in the photo for the product. It says 1 in the cart, because thats the price for one set of four.
    • Jkap
      Which one do you recommend me more one step colder or two step boosting 18psi?
      1 Answer
      • Customer Service Rep

        We do not recommend going to two step colder plugs until you go over 20 psi.
    • Luis Sanchez
      I'm still learning about the csrt4, which set would you recommend on a caliber that has a intake and diablo tune, I was looking at the other question people left and got confused? Thanks!
      1 Answer
      • Customer Service Rep

        The general rule, is that if you have stock boost levels, you use stock heat range. If you have a stock turbo but higher boost levels, get one range colder. If you have a larger turbo and even higher boost levels, then get two ranges colder.
    • Simon blackburn
      My Caliber SRT4 is stock and has the Stage 1 mopar Tune on it. Which option should i take ? Stock , step 1 colder or step 2? And which gap 0.35 or .32 ?
      1 Answer
      • Customer Service Rep

        If you have increased boost, then get one range colder plugs. The higher the boost, the lower the gap should be. You would be fine between .032-.035 gap.