Expensive spark plugs....worth it??
Expensive spark plugs....worth it??
Author
Discussion

markh1

Original Poster:

2,846 posts

238 months

Friday 8th October 2010
quotequote all
Just on Ebay looking to get some new plugs for the TVR and the Omega and there are some that are priced at a couple of quid each and others that are several multiples of this. Do they really make a difference??

E.g.

Cheap....

http://cgi.ebay.co.uk/Vauxhall-Omega-3-0-V6-Spark-...

Expensive....

http://cgi.ebay.co.uk/NGK-Iridium-Spark-Plugs-VAUX...

Cheers,

RobCrezz

7,892 posts

237 months

Friday 8th October 2010
quotequote all
Iridiums last longer, simple as that. If you dont mind changing them every 10k miles then go for cheaper copper plugs smile


Edit: that doesnt mean the coppers will only last 10k miles, I just mean that they wont last as long.

Edited by RobCrezz on Friday 8th October 14:25

ILoveSpeedBumps

57 posts

192 months

Friday 8th October 2010
quotequote all
Well ive just found this on the NGK website:

"Outstanding acceleration, high fuel efficiency and durability"

Clearly you dont even need a TVR just a 1.0 litre corse with the expensive options.

The more expensive ones will be made using iridium. These have been known to give an increase in power, the increase depending on engine size and number of cylinders.

RobCrezz

7,892 posts

237 months

Friday 8th October 2010
quotequote all
ILoveSpeedBumps said:
The more expensive ones will be made using iridium. These have been known to give an increase in power, the increase depending on engine size and number of cylinders.
Haha, no they bloody dont!

8400rpm

1,777 posts

196 months

Friday 8th October 2010
quotequote all
RobCrezz said:
ILoveSpeedBumps said:
The more expensive ones will be made using iridium. These have been known to give an increase in power, the increase depending on engine size and number of cylinders.
Haha, no they bloody dont!
Indeed.

Even with a car that revs to 9,300rpm and an output of 134bhp/litre N/A (it isn't standard), I just use copper NGK plugs and change them out every 5,000 miles.

I certainly couldn't notice a difference between the coppers and a set of OEM Platinums that the car came with new.

TommyBuoy

1,298 posts

196 months

Friday 8th October 2010
quotequote all
ILoveSpeedBumps said:
Well ive just found this on the NGK website:

"Outstanding acceleration, high fuel efficiency and durability"

Clearly you dont even need a TVR just a 1.0 litre corse with the expensive options.

The more expensive ones will be made using iridium. These have been known to give an increase in power, the increase depending on engine size and number of cylinders.
I'm thinking this is sarcasm?

By the way, when I had my old nasty spark plugs changed the car did seem to sounds better, BUT I am assuming this is all in my head!

HellDiver

5,708 posts

211 months

Friday 8th October 2010
quotequote all
Some engines need Iridiums, though. Try running a Ford Duratec on elcheapo plugs and you'll soon discover this.

RobCrezz

7,892 posts

237 months

Friday 8th October 2010
quotequote all
HellDiver said:
Some engines need Iridiums, though. Try running a Ford Duratec on elcheapo plugs and you'll soon discover this.
Eh? why?

Surely it would just mean you need to change the gaps on the copper plugs to suit?

HellDiver

5,708 posts

211 months

Friday 8th October 2010
quotequote all
RobCrezz said:
Surely it would just mean you need to change the gaps on the copper plugs to suit?
No, it's not that simple.

RobCrezz

7,892 posts

237 months

Friday 8th October 2010
quotequote all
HellDiver said:
RobCrezz said:
Surely it would just mean you need to change the gaps on the copper plugs to suit?
No, it's not that simple.
So what is the reason?

TommyBuoy

1,298 posts

196 months

Friday 8th October 2010
quotequote all
HellDiver said:
RobCrezz said:
Surely it would just mean you need to change the gaps on the copper plugs to suit?
No, it's not that simple.
What is the difference between the cheaper plugs and the ones suitable for the ford? I was under the impression that it was just the component material that changed - longer life etc. and that the spark created would be the same as the voltage / amp etc. is constant (i.e. the plug is not affecting the voltage / amp etc.)

ETA: I keep getting beaten to the point!

Edited by TommyBuoy on Friday 8th October 14:52

Dog Star

17,546 posts

197 months

Friday 8th October 2010
quotequote all
Try somewhere like GSF for Bosch iridium plugs: cheap as chips if you ask nicely (my car takes 16 of them and it was about 48 quid)

HellDiver

5,708 posts

211 months

Friday 8th October 2010
quotequote all
I tried normal NGK plugs, got misfires under load etc. Fannied about with gaps, yadda yadda, never got the car going properly. Swapped for NGK Iridiums and away it went, not a problem.

My findings were not isolated, check any Ford forum and you'll see lots of people reporting the same thing. I assume the engine needs Iridiums, as that's what they're fitted with from the factory, it's what Ford fit in servicing. I got mine from Euro Car Parts for 1/3 the price Ford were selling them.


MarJay

2,180 posts

204 months

Friday 8th October 2010
quotequote all
Iridium plugs last a bit longer than normal plugs. They don't provide extra power, torque or sex appeal.

Not worth it IMO.

jon-

16,534 posts

245 months

Friday 8th October 2010
quotequote all
If anything, the one tests I've seen show the copper plugs provide the better spark.

That, and the tips don't snap off in the engine smile

BadgerBill

274 posts

268 months

Friday 8th October 2010
quotequote all
Not 100% relevant, but SAAB's do need a particular plug due to the way the engine management actually uses them as a sensor in the Anti-Knock System.

http://en.wikipedia.org/wiki/Saab_Direct_Ignition

"The system puts a low voltage over the spark plugs when they are not fired to measure ionization in the cylinders. The ionic current measurement is used to replace the ordinary cam phase sensor, knock sensor and misfire measurement function."

Use El-Cheapo's and it doesn't work well/for long.

BB

ILoveSpeedBumps

57 posts

192 months

Sunday 10th October 2010
quotequote all
TommyBuoy said:
ILoveSpeedBumps said:
Well ive just found this on the NGK website:

"Outstanding acceleration, high fuel efficiency and durability"

Clearly you dont even need a TVR just a 1.0 litre corse with the expensive options.

The more expensive ones will be made using iridium. These have been known to give an increase in power, the increase depending on engine size and number of cylinders.
I'm thinking this is sarcasm?

By the way, when I had my old nasty spark plugs changed the car did seem to sounds better, BUT I am assuming this is all in my head!
The first bit was sarcasm but the last bit wasnt. Youll get about 2 or 3 bhp with better plugs, which will be alot more noticeable in a smaller engined car.

Ozzie Osmond

21,189 posts

275 months

Sunday 10th October 2010
quotequote all
Longer life.

Cleaner firing at high rpm in conjunction with suitable modern ignition system.




It's like buying "good" tyres or "adequate" tyres.

Dr Doofenshmirtz

16,952 posts

229 months

Sunday 10th October 2010
quotequote all
The NGK Iridium plugs have a much smaller tip, which means a more powerful 'focused' spark. They also last 60'000k miles+.

useyourdellusion

5,648 posts

219 months

Monday 11th October 2010
quotequote all
Dog Star said:
Try somewhere like GSF for Bosch iridium plugs: cheap as chips if you ask nicely (my car takes 16 of them and it was about 48 quid)
16? What have you got?