*NGK 91578* is the NGK Laser Iridium spark plug, model *ILZKR7B11*.
*What it is:*
- *Type*: Laser Iridium - premium plug with a fine iridium tip and platinum ground electrode
- *Heat range*: 7 - one step colder than the 6643 you asked about earlier
- *Thread*: 14mm x 26.5mm reach, 12mm hex
- *Gap*: 1.1mm pre-gapped
*What it fits*: This one’s common on modern Honda, Acura, and some Toyota/Lexus engines. You’ll see it on 3.5L V6s like the J35 in the Honda Pilot, Ridgeline, and Acura MDX from ∼2016 onward.
It’s designed for 120k mile service intervals and direct injection engines.
Running into misfires, or just checking what fits your car?