NGK Spark Plug Gap for 2012 Toyota Corolla


I want to change my car spark plug and bought NGK ILKAR7B11 Iridium spark plugs that was suggested for my Toyota Corolla 2012. As everyone suggests to check for the gap, I checked with feeler gauge and it was around 1.01mm instead of 1.1mm. I could see from google search/reviews that it was pre-gapped and can be used straightaway. However I'm seeing some difference when I measure with feeler gauge.

Had anyone had similar experience with NGK Iridium plugs?

Thanks in advance.


  • +3 votes

    Near enough for Corolla tolerances


      Alright, thanks. That should be fine in that case.


    You aren't supposed to check the gap on iridium spark plugs, they come pre-gapped from factory and anything going in between could damage the iridium tip.

    A slightly smaller gap will be fine, your coil won't have to work as hard, and I doubt that you would notice any performance loss.


      You aren't supposed to check the gap on iridium spark plugs

      I can't say for all brands but NGK say you can check and adjust them, you just have to know how to do it ie not lever off the tip.


        The point is that it is not necessary.
        Just like replacing them in modern cars in most cases.
        OP… Be careful not to overtighten when you install them. Threads in alloy heads strip easy.


        Not with the iridium ones, the electrode is too fine for that.

        Furthermore, you could break the iridium(precious metal) tip off and ruin the plug.


          The article you link to says:

          It is possible to adjust the electrode gap on precious metal spark plugs using an appropriate method that will not place any force on the centre electrode tip.

          They just don't want you wedging a screwdriver tip in there.

          I use side cutters to open the gap.
          Wire gauge gap checkers work best


            @brad1-8tsi: Why would you? NGK Iridiums are pre-gapped from factory! Thats so YOU DONT HAVE TO CHECK IT.

            Read the first sentence from the article I linked. The second and third words are in bold, so there is no confusion.


              @Cartman2530: I check them because I've received spark plugs that are incorrectly gapped (many times)

              I'm not on the tools professionally any more but it's a habit that was instilled in me from the first time I did a tune up. You just do it to avoid rework.

              • +1 vote

                @brad1-8tsi: Fair enough, but the point I'm trying to make in the OP's situation it will make no difference and he is likely to damage them if he tries to re-gap them, and a very slightly smaller gap will not reduce performance on a 2012 corolla unless its majorly worked. I'm just saving him from possibly ruining a $25 spark plug.


                  @Cartman2530: Fair call.

                  Gap them small and you'll get an extra 20k before they need changing. ;-p


      Thanks for the information.


    Thanks all for your inputs.

    I have changed the spark plugs and the older spark plug gaps are similar to new ones.

    I can see that black circle in the middle on all 4 plugs.