Spark plug NGK or Autolite

As long as you use the right type and gapped correctly, then you are fine. NGK, Autolite, Motorcraft, bosch, all are fine.

Autolite is the brand I got through rock auto.

I have been running them for 50,000 miles with is20 then is38 setup. Work perfect.

I just ordered new spark plugs and an oil filter as well.

I just did the change myself on my Gen 1 Mazda 3. It's simple! I used NGK Laser Iridiums.

The NGK's worked beautifuly.

I used NGK, 6 month no issues.

For a stock 4.3 you won’t see any performance difference regardless of what you put in there. Cheap copper plugs will work great but your going to be replacing them every 25-30,000 miles, iridium will probably last as long as the rest of the vehicle.

Yesterday, I installed new spark plugs in my 2004 TJ. Going off [this thread](https://wranglertjforum.com/threads/what-are-the-best-spark-plugs-for-my-jeep-wrangler-tj-4-0.4196/) I purchased the Autolite XP985. Originally, I gapped the plugs to .04 based on [this thread](https://wranglertjforum.com/threads/spark-plug-gap-for-4-0.17415/). The jeep ran terribly and actually threw a check engine light.

I went back today and changed all the gaps to .035 based on the note under the hood, but I still think the idle is a bit rougher then what it was before the change.

If these are for a TJ (97-05) return them and get NTK (NGK). The 4.0 will not like anything else.