Spark plug Bosch or Denso

Went with Bosh double platinum plugs at 60,000km when I notice a stumble at idle and that's the interval for change. I instantly went from best of 9.6L/100km to 7.8L/100km big difference in performance and smoothness and i prefer a German plug in a German car with Bosch electronics.

I'd stick with the WR6DPO Bosch. Not sure why but they just work with no questions.

I've been running Denso IKH24 for 10k miles, have to swap them often but they've been great so far. Frequent changing will prevent damage to them seeing as they are normal projected grounds, but they are pretty cheap to replace once a year or so.

I run [Denso 5749](https://www.densoproducts.com/denso-5749-ikh01-24-iridium-racing-plug) non projected tip plugs with my FBO IS38 car.

They're 1 step colder, and non projected so the risk of a strap breaking off [\(like this\)](https://i.imgur.com/gdJFaJ4.jpeg) are extremely rare.

Denso or Bosh are the best you can return and get new ones

Use NGK and if you can’t find them then go Denso. The only 2 plug brands I would put in a Honda.

For what it's worth, I've changed my plugs twice (OEM to Denso to Beru-RS7) and never noticed any oil or any difference in color between the plugs.

Although I prefer Bosch sensors over other brands in certain parts of my Mk 5 2.5, I will not buy Bosch spark plugs. Many professional mechanics over the last 3 decades have told me horror stories about them.

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...