Badmouthing Bosch plat. plugs why???

[Beancooker]

I hear a lot of people saying bosch plat plugs are bad for our cars, why? I replaced my plugs 6k mi ago with bosch plat 4's and love them. Now were my old plugs so bad when I put in bosch I thought they were good, but would have noticed better performance out of a different plug?

[maxhopper]

My distaste for them comes from personal experience. I have personally tried Bosch Plats in 2 different vehicles that I've owned. Each time I ended up switching to OEM replacement plug. They always seem to give an erratic idle.

I have never tried the 4's, so maybe they work better than the regular Plats.

[AZhitman]

I got the word straight frmo a Bosch plg engineer who said that they are not an appropriate replacement for NGK plugs.

I have also seen / heard of the electrodes actually breaking off in the combustion chamber of a VH45DE.

Bottom line is this: Electricity takes the path of least resistance. 4 electrodes are as useful as balls on a nun. One electrode, opne spark, regardless of how many Splitfire / Plus-4 plugs you install.

[C-Kwik]

I've noticed small issues n every +4 plug I've tried. Even cured a friend's idle problems when I discovered he had the +4's in his integra a few months back.

Consider that combustion chamber disigns are quite intricate now. Enineers try to control spark location and orientation as much as possible to make sure the spark will be good each time. interestingly I helped replace some plugs on a 99 Camry before and they use a dual electrode plug. These were OEM parts. I'm sure Toyota designed the motor to optimize these plugs.

Greg mentioned spark takes the lease resistance. All else equal, it's going to be the shortest distance. That said, the only real benefit to a multi-eletrode plug is longevity. Since a spar event wears metal each time it fires, havint 2 electrodes would probably have twice the life. But with platinum plugs life is already quite long as it is. Personally, I think it's a waste. And this is based on my actual experiences.

[Beancooker]

Thanks, maybe I'll be changing plugs soon.

[Chris92SE]

A few years ago I talked to a Nissan Tech that told me for some reason Bosch plugs don't work well with Nissan coil packs. He couldn't explain why, but he told me on many instances, Maximas that he had to replace coil packs on had Bosch plugs in there. This was in talks specifically about 3rd gen Maximas (VE30DE engine), but I can't recall if he meant all Maximas or not.

I have no science or anything to back this claim, but I took his word for it and stick with NGK.

[IvoryJ30t]

i use ngk copper plugs in my vq30

i would not put bosch plugs in anything but a german car.