Spark plug Bosch or NGK

NGK spark plugs are preferred in rotary engine (RE) Mazdas and Nippondenso is the only acceptable substitute that I ever found. We dealership technicians, always found it remarkable how a set of Champion or AC spark plugs could instantly cripple a rotary powered Mazda.

My 2017 Jetta SEL with LFER7BHX 9512 plugs starts/runs fine at 50076 miles, 0-100 degrees F.

You can run NGK Rutheniums, i run them on with my is20 and no complaints either.

I swapped for Rutheniums, No complaints and its a easy job

Stick to NGK R7437s. They are pricey but the best plug for a tuned car forsure. I inspect the gap every 5k miles and replace every 10k. Mine are gapped to .022

I’d go with the recommended NGKs, buy from fcp euro and you only need to pay for them once. Those are what I run on APR stage 2.

I went ahead with an NGK Laser Iridium. Compared the ones from the engine and the new ones and were identical in shape and form. It does seem to work fine after testing it.

I run RS3 coils with RS7 NGK plugs in my Unitronic Stage 2 GTI. These things really are unnecessary for anything stage 1.

Subaru's like NGK (OEM) spark plugs and O2 sensors, respectively. They run poorly and will even throw codes if other parts are used.

Worst case of electrode wear I've seen was on a set of Bosch 3-electrode plugs in a VR6. Plugs were so far gone, that five of six had triangular shaped center electrodes. Really thought I was gonna gall the head threads they'd been in so long.