Slam all pak wheelers friends,
From few weeks, I was noticing down performance of my corolla on cng as well petrol, so I decided to check all my engine related stuff like filters, spark plugs e.t.c then i found problem in spark plugs are "farigh".
After cleaning stock denso K16RU11, found its main electrode melted, so i decided to change my stock plugs to high performance in both operation cng & petrol, after extreme search i discover Brisk 3tip spark plugs looks like Mercedes oem type, Brisk is oem of lamborghini & audi also, like Bosch.
These are one step colder then stock, after installation feel amazing result in cold start, idle & acceleration.