Time for new spark plugs

[e21pilot]

At almost 240K miles, it is once again time for new plugs and wires. I'm going to get the Motorcraft wires but am not sure about the plugs.

My goal is to tune up the 4.0 V6 so it passes the state emissions test one more time. Does any one of those fancy geometry plugs really make a difference that would show up on the emissions test or should I just stick with the factory plugs again?

 

[bmerr98]

I am no expert, but it seems to me the way the O2 sensors work, they want a certain amount of fuelxygen in the exhaust, and the signal they send to the ECU helps regulate how much fuel is fed, blah, blah, blah...

Anyway, the high tech super spark plugs with 12 electrodes for maximum fuel burn and all that, no matter how much fuel they burn, the O2 sensors still want what they want, and the ECU will adjust accordingly. I've heard that Fords especially have very tightly regulated fuel systems that are hard to fool.

For my money I'd just stick with the Motorcraft and roll for another 240K.

 

[adsm08]

The Motorcraft plugs really are the best ones for the Cologne engines. They tend to run kinda funny on anything else. I am currently running MC platinum in my 4.0 and they seem to be doing the job very well.

Bmerr is mostly right about his O2 sensor statement, but he's off on a few details. For one, it's an oxygen sensor, not a fuel and oxygen sensor. It only sees oxygen in the exhaust, so a dead miss where all the fuel and oxygen from the charge go down the pipe looks the same to it as if you don't put enough fuel in and don't use all the oxygen. The type of plug you urn by itself won't have much of an effect on that.

 

[RebelRider2010]

Coming from the Bronco world, I was trained to hate platinum plugs.

Now im in the ranger world, with a 2006 4.0, do these prefer the platinum?