me and my fiance only use bosch, and heard from a lot of people they dont work right in the 3.8.... well, yesterday i was investigating all of the problems to cause my missfire, i checked the spark plugs (they are bosch) and they werent gapped right as the book says it should be .060, they were closer than that, i gapped them right and now the missfire is gone and can get upto speed fine, so if there is anyone like us about the bosch just gap them before you put them in.

 

You might also want to look into Denso:
- Camaro RS V6 Project Car

 

standard Bosch plugs and the Bosch platinum which have the normal design work ok in the 3800 but the exotic P+2 and P+4 plugs do not work well in this engine. The side electrode design works well in high revving engines but not so much in lower revving engines.

Massey

 

You mean there are people out there that do not gap their plugs? I would never install any manufactures plug without checking the gap. Its very rare, if ever, that I have install a set of plugs and atlease one needed some tweaking and that is me installing 100's of sets.

 

I always gap aswell. Most plugs are for more than on car so most aren't gapped

 

What's the best tool for iridium plug gapping? The usual disc tool is not it.

 

I learned that you always have to gap the plugs yourself. Shop manuals even tell you that. Since the plugs can fit in more than one type of vehicle, they can't gap them from factory.

That being said, Bosch plugs do suck. They are great for imports but not domestics. NGK is the best, or AC Delco. (NGK makes AC Delco plugs).