Spark plug Bosch or Motorcraft

I had good luck with ngk bp6hs, Bosch w8Bc, champion l87yc and renault oem short thread (yes, really.) plugs. Bosch w8ac used to be good but i had some arrive not working out of the box recently so I'm now avoiding them.

the spark plug is less than 10k km old (bosch) so I initially did not change it. Decided to change it anyway to original mercedes (turns out made my NGK) bam emission passed, LTFT now hovers at 5-8%.

I've changed my spark plugs three times, always with the Bosch Iridium, never had any problems. Pre-gapped, takes me about 30 minutes from start to finish. Lasts me about 90,000 miles.

The new ignition switch is in. The spark plug wires are Bosch copper and now have the Bosch super 3 ground electrode plugs installed. So with a fresh ignition switch that eliminated the odd electrical changes we were seeing in the dash lights, now stronger cranking and it does run better.

Bosch W6DPO. They’ve always been expensive, but now stupidly so. I’m not paying $250 for plugs, either. The DENSO IW20TT you referenced is a perfect replacement because it’s the exact same heat range as the W6DPO.

Ja tive problema com velas bosch. NGK é melhor.

Has anyone tried the Motorcraft SP594 plugs? They supercede from the SP542, which is said to be a 1 step colder plug for our cars. Currently running NGK 6510s but i think i got a "fake" set as i paid like $30 from Amazon for them. The SP594s I can get for $41 from Ford... so anyone have good results?

Iridium plugs suck on fords.

Ever since Bosch moved spark plug production to Russia, the quality has been sketchy.

I replaced my sparkplugs, and everything went smoothly except for the front plug on the driver's side. All the other spark plugs screwed in with little to no need for a socket wrench - except for tightening at the end.

This one plug seems to be stuck halfway down the middle of the thread and won't go deeper unless I really torque it. When I took the new spark plug out, I noticed that the tip was bent with the spark gap being much smaller than the other new piece.