Copper or Iridium Plugs???

[snike77]

Hi

Could anyone tell me which would be better out of copper or iridium spark plugs,

Ive read a lot about iridium being longer lasting etc, but ive also read that they are more designed for harder driving or higher revs, and ive heard that for normal daily driving copper would be better??

Has anyone got any advice in regards to this

thanks

[CrunchyAdams82]

Iridium.

I think a better/more controversial question would be;

Iridium or Platinum. Which is best?

I'd personally go with some NGK Iridiums for an everyday application though tbh. Great performance, reliability, & relatively cheap.

[Merlin]

Like Crunchy says, commonly its Iridium or Platinum for the Prelude. Both are good.

Iridium are something like 25K miles
Platinum's are 60K.

[snike77]

Ok thanks

Also, do you think it is worth changing the HT leads,

Again, ive read conflicting things where some people say yes, and some people say no as the OEM Honda leads are far better than anything aftermarket

[NafemanNathan]

Both Iridium and platinum last longer, but...

"Many people come to the point where they are forced to change the spark plugs on their vehicle and face a difficult decision; copper spark plugs or those of another type? You can find spark plugs in a variety of different metal combinations, including aluminum spark plugs, iridium plugs, platinum and more. Copper core spark plugs are still the most commonly seen, however, and many people agree that they are the best. However, the advertising that accompanies the different types of spark plugs is potentially misleading, so it's important to recognize the real difference between the spark plugs in question. In order to do that, it's necessary to first learn about what the metal in the spark plug is used for.
Purpose of the Metal

The metal in a spark plug serves a single basic purpose: to channel the electric energy from the plug wire through the spark plug so that it can be forced to the engine block in the form of a spark. Therefore, any metal that conducts electricity at all could potentially be used for a spark plug. The metal should also not get too hot; one of the main problems with some metals is that they overheat quickly, causing the electric charge itself to be compromised and the spark plug to not operate as smoothly.
Copper Spark Plugs

Copper spark plugs are generally considered to have the best performance of any spark plug type. This is potentially different from what advertising companies suggest, but the other metals are, unfortunately, not as conductive in general as copper is. Platinum and iridium plugs are more likely to overheat, which causes damage to the plug components and can compromise the delivery of the spark to the engine block.
Platinum and Iridium Plugs

Platinum and Iridium plugs perform at a lower level than copper spark plugs, because they are less conductive and they tend to overheat. However, the overall longevity of these two types of metal is better than copper plugs. In reality, copper has the best performance of all three and the worst longevity. Platinum has good longevity and the worst performance. Iridium has good longevity and a performance that is decent, which is why iridium plugs tend to be more expensive than any other type. Still, the difference between these plugs in terms of overall quality is minimal, as there is a trade off for each.

Most copper plugs need to be changed every 20,000 miles or so. Platinum and iridium plugs can often go for twice that before they require changing, but the overall performance will not be as good and you may have to deal with overheating of the plugs. This is potentially not worth the added cost of both platinum and iridium spark plugs, although the decision will depend upon your preference."

[Merlin]

One other thing to take in to consideration is that Honda spec NGK Platinum's in the Prelude.

[CrunchyAdams82]

If your leads need changing, go for some Magnecor KV85's. If everything is working well & as it should; leave them I'd say.

(Unless you're happy to spend the money of course! In which case I'd say buy the Magnecor's anyway. They'll give you great performance, and most likely last the lifetime of the engine tbh. Win)

[CrunchyAdams82]

What engine do you have in your Gen5?

[snike77]

In my 5th gen its only the 20i 16v (F20) engine,

What did you mean Merlin about the Honda spec NGK plugs?

[Merlin]

Honda put NGK Platinum plugs in the Prelude.