I have a 2002 F150 ,4.6V8 with 42,000 miles on it.
I was wondering when I should change spark plugs.They say 100,000 miles but that seems a little long for something that gets hot and creates explosions thousands of times a minute.I want to get better throttle response and more power.
Could you tell me what the best spark plugs are for my engine?

Thanks a whole bunch.
There is alot of great information in these forums.

 

Well, theres OEM motorcraft double platinum plugs, long life but slightly less performance.

I did some rummageing around on this forum about plugs and there were a lot of posts about copper core plugs and performance.

I had changed my plugs to platinums and wasn't that happy myself. Just after a month of the plats, I tried the motorcraft coppercore plugs, and it made the difference for me.
I'll need to change them yearly.

As always, you mileage may vary.

 

I pulled the factory plugs out of my 97 4.6L with almost 60K miles on them. The electrodes looked good and they probably could have gone 100K miles. But, the plugs had corroded severely on the oustide and were extremely hard to remove since there wasn't much left for the socket to grab onto.

It appears the outer parts of the Motorcraft plugs are not platinum plated. I live in a very humid climate, and it would seem it's a little too harsh for the factory plugs. (Before someone says it, I don't have any radiator hose leaks).

Contrary to the advice given on this forum, I put in a set of the much maligned $2 Bosch Platinum plugs and I couldn't be happier.