Spark plug Bosch or Champion

As for the spark plugs, both Bosch Iridium and NGK Laser Iridiums are fine, arguably even better than OEM (which are made by Denso, btw).

I have a stack of 25+ index cards filled with notes about the care and service of the car. The factory service manual has notes and highlighted areas all over it.

Replaced spark plugs with genuine VW Bosch units

Replace those plugs with nothing other than the Champion 7989 plugs. They are about $14 each and they are a 1 piece design.

Belated follow up. I replaced the plug at the distributer as the signal from the hall sender was intermittent. Brand new Bosch plugs were had for cheap.

So I grab a new ignition coil, and a full set (4) of spark plugs. The Pre-gapped BOSCH Iridium plugs were the same price as OEM platinum, so I figured that's fine for me.

After pulling the plugs, Cylinder 1 plug was definitely eroded. The other 3 plugs looked fine, but I might as well replace the lot. The new Ignition Coil went into Cylinder 1 as well, and I started it up.

Check engine light went off, starts up fine, drives fine, idles fine.

Been using bkr7e since 2007. They are ok, but not optimal in any way. Im now running Bosch F5DPOR. \"OEM Audi RS2\" They are gap free, and runs perfect at least at 15psi in my car.

In my experience, Bosch spark plugs are always terrible; fouling out within a month, that kind of thing...

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.

I found Bosch platinum plugs misfired intermittently on GM v8s with the optispark distributor despite being identical to the Delcos.