Reading spark plugs - when to change

[lmoengnr]

I installed a new exhaust system, so safer to remove the plugs then to drop extractors on them which will generally brake them.

My car is not stock, i.e intake/exhaust/tune already done prior to install of new exhaust system. Most likely I'd say tune related but not fussed that they didn't last 140k.
They are cheap to buy and very easy to replace.

It might work if you go one step 'colder' in the heat range.

 

[07GTS]

just go a cheap tr6 and leave gap at 1mm will be fine on petrol, any of the fancy plugs are not better for performance only economy/longevity

 

[Skylarking]

just go a cheap tr6 and leave gap at 1mm will be fine on petrol, any of the fancy plugs are not better for performance only economy/longevity

Isn’t part of the logic for using long life plugs related to engine bay packaging issues making it a PITA to remove some of the plugs in some engines. Long life plugs solve such issues as it doesn’t have to be done every 40-50k kms.

Long life plugs also have the following benefit over the lesser brethren (according to AcDelco):

• Improved cold-starting and acceleration characteristics
• Provides a more focused ignition for better overall ignitability
• Reduced ignition system voltage demands saves wear and tear
• Spark gap remains virtually unchanged during the life of the plug

But using long life plugs is probably not so relevant if you like fiddling with engine mods, tunes, etc, as you’ll be changing/checking your plugs more often (maybe trying to get tune and/or heat range sorted which I assume a pro & home tuner would want to be doing?). TR6’s with their V groove is probably almost as good

 

[Immortality]

I like the little Qualifier.

Long life plugs are good because, well, long life....

 

[Skylarking]

I like the little Qualifier.

Long life plugs are good because, well, long life....

Well yeah... they are

Service intervals are important to some...

Question is, how much of the plug cost is for a share in service cost savings and how much is for the increased manufacturing costs due to those expensive iridium/platinum coatings. I’d think the majority of the extra $$ they charge for their share of your savings

 

[Big Red VF-SII Go-kart]

Service intervals are important to some...

You bet!
Drivers, travellers... those with a real-world, need-for-reliability and longer service intervals ... view longer service intervals as a blessing, and over the last few years the intervals have become longer as cars become more sophisticated in their engineering and management. Enthusiasts though, are keen on over-servicing and modifications that dramatically change engine behaviour, often for the worse (shortened engine life through being forced to work harder and hotter). I suspect the plugs shown in one of the foregoing posts is indicative of a tune that has gone wrong and will show up something more worrying. This is what enthusiasts do (and worse still if you look at the silly FaceAche posts e.g. Club VF, among others: there's a good reason those groups are private because of the shocking activity that takes place there).

 

[07GTS]

Isn’t part of the logic for using long life plugs related to engine bay packaging issues making it a PITA to remove some of the plugs in some engines. Long life plugs solve such issues as it doesn’t have to be done every 40-50k kms.

Long life plugs also have the following benefit over the lesser brethren (according to AcDelco):

• Improved cold-starting and acceleration characteristics
• Provides a more focused ignition for better overall ignitability
• Reduced ignition system voltage demands saves wear and tear
• Spark gap remains virtually unchanged during the life of the plug

But using long life plugs is probably not so relevant if you like fiddling with engine mods, tunes, etc, as you’ll be changing/checking your plugs more often (maybe trying to get tune and/or heat range sorted which I assume a pro & home tuner would want to be doing?). TR6’s with their V groove is probably almost as good

yep u want them to last get the fancy ones, u want performance and adjustability go the cheaper, anything with the iridium tip gets super hot which is good for emissions but too hot can cause pre ign in performance engines (more so boosted), the tr6 full set $50 every 12 months is easily affordable to me and can adjust them to suit gap easily, i find them not too bad to remove also as have done it quite a few times (less clutter in my engine bay also helps) had few issues too with a miss and so simple to take a bank out and check them and u can see which ones arnt firing right, being a performance boosted engine my servicing/checking over is prob more then most do on the every day engines

 

[Anthony121]

The look good. All 8 of mine were similar to these, so I replaced them with stock plugs. 47.5k the car has travelled. My car is not stock though.

View attachment 216558

You must be hard on your Redline

 

[3rspecB]

You must be hard on your Redline

I don't worry about fuel economy

 

[Immortality]

yep u want them to last get the fancy ones, u want performance and adjustability go the cheaper, anything with the iridium tip gets super hot which is good for emissions but too hot can cause pre ign in performance engines (more so boosted), the tr6 full set $50 every 12 months is easily affordable to me and can adjust them to suit gap easily, i find them not too bad to remove also as have done it quite a few times (less clutter in my engine bay also helps) had few issues too with a miss and so simple to take a bank out and check them and u can see which ones arnt firing right, being a performance boosted engine my servicing/checking over is prob more then most do on the every day engines

Yup. I get my plugs from the US at us$1.28 each. I buy multiple sets . I had iridium But I dont think more boost agreed with em. I was running 1 step colder but going to try 2 steps cooler next...