Owner reviews for spark plug

Use only Honda specified plugs (usually Denso Iridium) and they last 100,000 miles just fine.

I find that chevies and dodges like autolite or delcos, fords i run motorcraft only, japanese stuff gets ngk's or bosch.

at 100k km, I replaced (all Bosch) Plugs , Coils, starter, battery, voltage regulator (40).

Note that decent spark plugs are hella expensive, but worth it due to lasting a lot longer than cheap $4 Autolite's.

I've use NGK products in American, Japanese and German vehicles for over 30 years with absolutely no problems at all. Note that NGK spark plugs come with a proprietary anti-seize coating on the threads, so no extra anti-seize is necessary at all.

I’m running NGK racing plugs # 4654 or R7437-9 no issues.

The NGK 5690 is a clone of the Bosch copper nickel FR7HE02 it’s cheaper and runs great in a 2.5. It’s actually oem for 170hp 2.5. Change it at 40k. It’s the last plug VW put in 2.5s so it should be the best one. It’s one notch colder than the NGK laser platinums. The NGK 5690 will allow the motor to pull more timing and more power. For best results use 91 or above. It’s even in the owners manual.

Also, some engines get particular about plugs. Bosch has a bad rep for the 3400 engine in my Grand Am, while NGK and AC Delco(I've got NGK Iridium IXs in there now) are fine.

Porcelain tip fell off one Denso spark plug in cylinder 1. Doing less the 200km distance. Motor is f@$ked.

Warning about Bosch spark plugs!!! The piece of ceramic around the electrode failed. These were in a 2018 sonata turbo for about 10k miles. Thank God it didn't fall in...