Spark plug Bosch or AC DELCO

I used the gimmicky Bosch Platinum 4+ plugs which solved that problem (no more CELs) but sometimes idle is still a bit rough.

I got a sp series cold air intake and ecs performance ignition coils with bosch spark plugs. I once ran this car with 3 spark plugs for to much time and almost no oil at one point too.

I couldn’t use any other spark plugs I had to use those or my car would run like crap.

In my 2012 with the 2.5L engine, I replaced my spark plugs with Bosch Iridium (#96302), around 90K miles. It's been great since.

My 2017 VW Jetta 1.4 5M - at 67760 miles on the factory original plugs - now has new Bosch Iridium/Plattinum plugs - (YA5KIP80)..................(the only symptom on the old plugs was a MPG drop - no hard starting, no missing, no rough idle......... EZ

I also added bosch sparkplugs 4 months ago, and also have some stuttering.

I don't say for 100% sure but my understanding is that Bosch and NGK are the ones you should use

My s2000 ate the Bosch plugs I put in, which were rated for the car/f20.

I changed the spark plugs on my X5 with Bosch ones. My mechanic showed signs of being upset with me for not bringing the genuine BMW ones... Fast forward to a week ago - the car throws a check engine light and OBD scan shows faulty oxygen sensor heater circuit. My mechanic linked this to the Bosch plugs, suggesting they might not be the correct type. I ended up replacing them with genuine BMW plugs and an O2 sensor, which cleared the codes and improved power. My learning is that Bosch has many SKUs, and it's hard to ensure the exact OE part number, potentially leading to incorrect plug types (e.g., 'double platinum' instead of 'laser iridium') for BMW, costing more in the long run.

I’ve had almost all of them destroy themselves recently.

A few months ago i had a intermittent misfire appear and went to investigate it but when I popped the hood while it was running, the wire on cyl 3 was literally popping and sucking itself in and out with the spark plug core still on. I took the plug out and the ceramic was moving in and out from the threaded bit. So it was gapping and slamming itself together while running.

I changed the one spark plug cause I had a spare ngk, I forgot about changing the rest and now I have a new misfire….. I can now feel the tick from combustion going thru the wires on cyl 1 and 4. So now 2 spark plugs are starting to do the same thing. I will be changing to ngk plugs now and won’t be touching Bosch.