What type of spark plugs does everyone prefer to run in there Dakota with the 3.9v6? Right now mine has either auto light or champion in it. I'm just curious to see what everyone prefers. I'm not real crazy about the auto light/Champion brand spark plugs but that's just my opinion. Thank you justin

 

I like NGK copper cores or anything copper really. When compared to platinum or iridium they are more conductive and produce less heat.

 

Generally go with the one called out. BUT if you drive hard or carry loads going ONE but NOT two, heat range colder. i tried a race plug, It DIDNT work. Stay very close to the plug called out!!

 

Bosch Platnium plus 4 best plug for 3.9 I've run mine for over a 150,000 miles with no problem what so ever. Engine runs smoother and accelerates better then the stock plugs.g

 

I use NGKs in everything. Bosch platinums are the worst f'ing spark plug ever created. If I get a vehicle in with a running condition and see those damn things, I don't go a step further until I get real plugs installed. 9 out of 10 times that fixes the problem.

 

I've been running copper Autolite 3923's in my 3.9 for over a year now. They've been p-e-r-f-e-c-t so far. Runs flawlessly.

*knocks on wood*