which are the best? money no object-well within reason of course! lol

jusdel30 said:

which are the best? money no object-well within reason of course! lol

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Standard NGK plugs of course.
US edition now recommending NGK Iridium plugs.
If you are not concerned about warranty - Denso iridium. There is two versions - I ordered the 'cheaper' IX ones last Friday for £38 for a set.
It is questionable if they give any better performance than standard.
Plugs should last 18k so they do not need to be changed between services.
It has been mentioned on a thread - either on the 500 or the Panda forum that the Denso give 2bhp - I don't really know.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=360218126885

There's a thread going on the 500 'site'. I'm looking for a bit of input as well.
https://www.fiatforum.com/500/263450-my-new-1-4-500-a-4.html

Based on previous experience of other cars, I would say OEM is best really. There is no performance advantage from fitting anything else.

i'll give em a look aye, thanks m8 for input-fiat forum is awesome theres always someone who knows bits

trackdayqueen said:

Based on previous experience of other cars, I would say OEM is best really. There is no performance advantage from fitting anything else.

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https://www.fiatforum.com/500/203411-spark-plugs-1-4-a.html

It would nice to get a copy of that RR graph.

Trouble is that RR graph showing 2bhp is not a viable difference. You could go back the next day and get 2bhp less, so it doesn't prove anything. The other factor is, if the old plugs were knackered, this would be enough to explain it, in itself.

For example on an old modified MR2 Supercharger I had, the plugs were not quite right. Changing the plugs made a 10bhp difference, from 172bhp to 182bhp. But obviously I wouldn't say the new plugs give 10bhp, it's more that the old plugs were losing power.

:yeahthat:

ive just put some denso iridium plugs in mine, cant say ive noticed much of a difference, but they can last to over 60k whereas normal plugs wont

Will the bodies last anything like 60k without significant rust? Even removing, cleaning up and replacing probably isn't worth the effort.

For plugs, I would recommend goin to a good trade motorfactors or search online. Usually they're so cheap for standard plugs it becomes a no-brainer.

spoke to denso mechanic today re the iridium plugs. he claims no gains in bhp just better performing acceleration response only. still ordered a set-not having to replace em for 60k sounds good to me!

I doubt there's any point in going away from the standard spec - as in many other things - gone are the days when some reputable makes of plug could actually cause damage. In the 70s, more highly-tuned Alfas could burn out pistons if you didn't fit Lodge's surface discharge plugs, those named after a famous wonder horse were particularly prone to melting pistons.

jusdel30 said:

spoke to denso mechanic today re the iridium plugs. he claims no gains in bhp just better performing acceleration response only. still ordered a set-not having to replace em for 60k sounds good to me!

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And how would you get improved acceleration response? I'm sorry, but that sounds very smelly to me. There are two ways to improve response, increase power or reduce inertia. We've already discussed that steady state power is unlikely to change, and I'd be interested to hear why transient power should be improved.

ring denso tech support for yourself m8 and ask them!

Well. I've put a set of denso iridium IXU22 plugs in a May 2009 Fiat 500 1.4 with 4,300 miles on the clock. It's next plug change will probably be in Nov 2012 (its due an oil change this Nov). The plugs in the car are the original ones since the car was bought new nearly 2 years ago.

I have noticed a difference. The pickup is a little quicker around 3000 revs. It's a small but appreciable difference. I would imagine that on the RR there would be no difference in bhp. The difference between the new Densos could well be down to slightly tired 'old' plugs that have done a lot of town mileage. I'm confident that they will perform better for longer than the standard NGKs. They 'feel' more lively than the NGK Iridium that was in my last 1.4 sport. I would say that that there's no difference between the standard NGK and the NGK Iridium but the Densos do feel better. I reckon they were worth the £9 a plug given the kind of money that one could spend on a supersprint exhaust system. I not worried about the warranty because the time these get changed I will be outside the warranty period.

On the last 2 pictures I found a piece of metal - 'left in' by the last mechanic (it would have been a Fiat mechanic) that was 'sitting in the engine'. Anyone know where it is supposed to go ! It must have been rattling away in there since the last service that was done in Nov 2010.