Hey All

I've just installed the above spark plugs (NGK Iridium IX's) into my 1.8 Stilo, and I thought I'd give my opinion in case anyone else was thinking about it.

The long and short of it is - I'm not buying them again! Don't get me wrong, they're very good, no doubt far superior compared to the originals. However, I've been a longterm fan of Bosch Super 4's (got Stu DemonD to get them ), and after taking them out and putting the IX's in, I've noticed the following:

• PRO - Improved fuel economy round town
• NO CHANGE - Acceleration is still smooth, starting warm is pretty much immediate. Took a bit longer when cold to start, but I'd just fitted them, so I'll forgive that.
• CON - Apparent loss of torque. Tried pulling away in second on a flat, car almost died! There was a flat spot when I got it that has seemed to come back.

Cost; I paid £35 delivered for the set. The Bosch Super 4's can be purchased for £15 on ebay.

I personally won't be buying them again, I shall go back to the Bosch plugs. Yes, economy will suffer, but the car seems to drive so much better and is more responsive on the Bosch plugs. And at less than half the cost, it makes sense to change them twice as much.

i want some bosch super 4's for my punto sporting, i fitted em in my sisters punto 8v and they made a good difference.

The Stilo coil on plug set up produces a massive spark and an advantage with coil on plug is a very precise spark timing. So altering plug types is probably pointless unless you already have major tuning alterations. Double pole plugs give longer life but they only spark on one of the gaps and on one side of the head so the other plug is scrap junk in the cylinder and just gets in the way of the cylinder ignition (as i found out with double poles in the Bravo, back to single pole from double pole- nice clean spark again).

Plugs designed to enhance or improve the spark will generally just get in the way of the precise timing

Hmmm you've got me all confused now Decks. Iridium IX are single electrode plugs while Super 4s have...four! So what's with all the gripes about 'double' pole? I've recently swapped to Super 4s and butt dyno says engine is more perky. But hey, what do I know?

Now don't be confused, I was talking about me Bravo which can have two electrode plugs or single. The problem with the double electrode plugs (or four point plugs) is the spark, which only occurs on one of the electrodes is all one sided and not in the centre as it would be on a single electrode and the rest of the electrodes are just doing nothing, in the way of the flame path. So multi point plugs are longer lasting but often to the deteriment of a clean spark in the right place

My Bravo came with double point plugs but when i put single points plugs in the difference in running and pick up was immediate

Have a look here
http://www.spark-plugs.co.uk/pages/technical/spark_plugs_faq.htm#best_Iridium

There's a lot of high brow conversations about plugs but you simply want a nice fat spark in the right place and at the right time

I had the Bosch in my 1.6 and verdict is as decks said no point of multi poles on a plug if the spark only uses one ..I went back to the NGK and glad I did ..Was speaking to a Shoowee owner on P/S today who has had a persistent flat spot and hesitation on his car ..went into Mangoletsi and they took out the Bosch and fitted a new set of NGK's ..result ..no flat spot or hesitation ..

Would just like to add another point that Decks hit upon and that if you fi Iridium you do it more for the reason and fact that your engine has been tuned to some extent ..no point if it hasn't been also to get the best out of them you really need to index the plugs as well on the inlet valve side of the engine ..pain in the arse to do but well worth it

PNL said:

I had the Bosch in my 1.6 and verdict is as decks said no point of multi poles on a plug if the spark only uses one ..I went back to the NGK and glad I did ..Was speaking to a Shoowee owner on P/S today who has had a persistent flat spot and hesitation on his car ..went into Mangoletsi and they took out the Bosch and fitted a new set of NGK's ..result ..no flat spot or hesitation ..

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See, I found the opposite - my 1.8 had a flat spot and hesitation, really bad, until I fitted the Super 4's.

Rich said:

See, I found the opposite - my 1.8 had a flat spot and hesitation, really bad, until I fitted the Super 4's.

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I can remember you saying that when you first fitted them and thats why I tried them [so its all your fault lol] shame the iridium dont fit the 1.6 as would have bought them off you ..[wrong code Number ]:bang: and Red devils shoowee is modified so that could well explain why the bosch dont cut it ..

Maybe there was a hesitation because the plugs were bad
It shouldn't hesitate at all on standard plugs, the plugs it was designed for

From talking to various tuners over the past 8-10 years, many seem to have come to the conclusion that Iridium plugs are better suited to "cold running" engines that run nitrous oxide injection and are pointless on a standard engine, even engines with bolt on mods (including cams).

I've never had a problem with the dual pole plugs in my Stilo.

well i fitted ngk ones into my punto today, cos they dont make bosch super 4's for the sporting

Maybe it's engine specific...I Fitted Super4's on my....1.8 and instantly noticed a different, plus, much more low down grunt...but that's just me!

tkmking said:

Maybe it's engine specific...I Fitted Super4's on my....1.8 and instantly noticed a different, plus, much more low down grunt...but that's just me!

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Give that man a medal, exactly the same as mine!

ive seen this on a few cars and even between same model cars that cetain plugs seem to suit some engines better.
on the turbo cinq super 4's were fitted on the conversion but when i had it ,it didnt like the super 4's.
however after a few years differences in fuelling,engine wear etc may be a factor

OK, guys whats the conclusion- which plugs should i go for NGK's, BOSCH, IRIDUM- i have an untuned 1.6 16v stilo dynamic 5dr- whats flat spot and hesitation, sometimes in my car i feel the car doesnt want to move, after rasing the clutch to bting point and apply gas, it feels like its gonna stall but then it starts moving, whats this called.

I have standard NGK's in mine at the moment didnt like the bosch still got them did about 100 miles on them if you want them to try your very welcome to have them

Mine did this until I used the Guide on here to clean the inlet control valve. Worth a try?

PNL said:

I have standard NGK's in mine at the moment didnt like the bosch still got them did about 100 miles on them if you want them to try your very welcome to have them

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Would like that very much, would it fit on my stilo 1.6 16v dynamic- will try these if no good, will purchase some NGK's.

cheers

FiatStilo02 said:

Would like that very much, would it fit on my stilo 1.6 16v dynamic- will try these if no good, will purchase some NGK's.

cheers

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Yes mine is a 1.6 dynamic 5Door :slayer:

PM me

PNL said:

Yes mine is a 1.6 dynamic 5Door :slayer:

PM me

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have done, btw whats your average MPG?