Well with all the hoopla about the bosch plug I went out and bought new Autolight XPs with iridium. I hope they are worth it at $6 apiece! They had copper for $1.39 but I went with the "you get what you pay for" decision on them. Anyone tell me which is really better if any difference?

There is only one thing though, the performance increase was on the local streets, local highways, and interstates. It wasn't a mileage issue, although my mileage is probably better w/ the Bosch, I didn't get a chance to check the mileage on the TR55s because I didn't like the way the car ran and swapped them out before I could make a determination.

Keep in mind I do expect these to have issues. Any plugs will, and these may be prone to it faster. When it happens, I'll probably try the Bosch Fusion +4s. I don't know.

I can't comment on your plugs, or your climate. I did comment on what the temps were here when I was running the Bosch and the TR55s. This stuff is like a religion here and I just don't get it.

If the +4s work better than anything else for me, why is that a threat to people here?

The threat is the cost, and the fact that they won't last. It'* not conjecture. They won't last, and even Bosch themselves have confirmed it. They know the issues.

Jared'* main reason for changing is that Platinum of any make/design should never be used in a Supercharged or Turbo application. Not even AC Delco or NGK platinums.

The rest of the threat is that your comments (still untested over time) may be enough to make someone else want to go out and try them, when we've ALREADY proven on this Forum time and time again that they won't last.

Would you put an accessory belt on your car of a brand that we've already proven lasts only half the time of a Gates or GoodYear?

Jared.... the copper core has been found to throw a better spark than the Iridiums, although the Iridiums will last much longer. It'* a toss up as to which is better for you.

You may want to check your ignition system. If you have weak spark then having more electrodes or a hotter firing plug may actually help your application and this may be why the Bosch are working well for you.

Just a thought.

My opinion is if your boosted and want performance get copper (although you will be changing them more often). If your boosted and want longevity in the plug go iridium.

Nothing lasts! There is a service interval for everything. If I have plugs that run GREAT for 12 months (or 6 months) and give me the performance that these do, then I'll use them and PLAN on swapping them when I need to. Hopefully the +4 Iridiums are Bosch'* answer to this problem!

To answer your question, if this new belt had a way of improving performance and mileage, yes I'd use it! I'd keep a spare new one in the trunk along with a wrench, but I would use it.

Why not? Why have something that runs poorer and doesn't need as much maintenance? If I wanted to do that, I'd buy a diesel!

I don't know if it'* a problem, but don't think so. When I had the NGKs in there it ran smoothly. It had the power to get up to speed on the highway, and to get up to the 109 mph max. All running smoothly.

But it took longer to get there and it had a little bit of hesitation when pulling off from a dead stop.

I know that the car has 87500 miles on it right now. I wouldn't think that the series II ignition would be that weak in just 87500 miles (But it is over ten years old)..

Keep in mind that the plugs I pulled (in the pics) all had the same patterns on them. So it'* not just one coil gone bad. I also put in brand new GM battery cables (2 positives and a Negative) and bought a new Die Hard Gold Battery when I re-did the LIM/UIM/Etc. So it'* probably not a power problem.

Is there a way to test the spark coming from the coils and get an accurate reading that we can publish and compare?

Chip, I don't know if you are purposely missing the point here, or what. It'* been stated a few times that what you chose to do to your car is totally up to you, as it is for any member. However, when it comes to information, and recommendations as a whole, the intent of the forum is to provide information that works best for the general membership.

Edit - The fact is that most people coming here are looking for reliability and longevity, not shaving a tenth or so off from their 1/4 mile times.

That'* not what I'm trying to do, but I understand your point. Thanks!