They do give some improvement, but (in my opinion) not worth the huge price tag. From the dyno results I have seen, they will give 0-5 HP gain over new OEM plugs; I didn't pay attention to dyno runs comparing them with old plugs, as those are basically meaningless.
I found this rather comprehensive spark plug comparison. The Pulstar plugs placed first, but not by much.
I am currently using ' NGK Iridium Spark Plugs '. Have not experienced any severe problems with them. I forget how much, but they were expensive. They have been in my engine for six months by now. The mazda four cylinder is still ticking over sweet.
My service technician explained, the Ford/Mazda joint development for the four cylinder escapes. I comprehend my escape is basically the Mazda Tribute. Different shape on the outside, but it shares the Tribute mechanical componentry. When the mechanic changes the escape oil filter, the indication on package is " Mazda Oil Filter ".
He popped the bonnet on a Mazda 3 model car. Took off, the fancy looking plastic area over manifold. With a smile he said ' There you go, it has exactly the same engine as your escape.'. It doesn't bother me. I have great trust in Mazda engineering. :happy: :thumb:
These " Iridium " plugs seem to be quite reliable. The mazda engine ,is not being compromised by use of this " IRIDIUM" technology. :thumb:
not worth the money. I heard some bad things about them. Heard some WRX melted the plugs and its a pain to remove them every 40 to 50 thousand miles. And for the price comeon!!!! Get NGK iridiums and they are much better. OR stick to the OEM and save a bundle.
I've had first-hand experience with them on my M3. I did a back-to-back dyno test, and picked up a very small amount of power. The big problems for me is that they wore out very fast, and were INCREDIBLY fragile. They are VERY easy to accidentally break.
Edit: I would not recommend these plugs to anyone. Stick with the leading Iridium plug and be happy.
I just got a 2005 Ford Escape XLS and I put in Autolite XP Xtreme Proformance Plugs, has anyone heard anything about these plugs? I saw a lot about the NGK iridium plugs, but I just bought the Autolite Plugs so I wanna see if I can use those instead, they seem to run great, my engine from start up lowers its idleing speed a lot easier now. I'm not sure how it does on fuel economy yet, I gotta do some more driving with them in. But, so far so good.