Spark Plug advice

[THE SpecB]

Hi folks

Any advice on or if the OEM plug is okay for Subaru service to use with a tuned GTB?

[Robbks]

Go to a standard NGK copper plug.
Std or V-Groove

More resistant to any knock events than platinum or iridium.
Just change at 20K regardless, but for $15 a set, who cares

[THE SpecB]

Go to a standard NGK copper plug.
Std or V-Groove

More resistant to any knock events than platinum or iridium.
Just change at 20K regardless, but for $15 a set, who cares

Thanks for advice but I'll be relying on what Subaru service install next week... Hopefully the right ones !!

[Robbks]

well there's no point in asking the question if you're relying on dealership serviceing.

[THE SpecB]

well there's no point in asking the question if you're relying on dealership serviceing.

I'm asking advice as if plugs are not suitable they will supply I'll have them changed to what is suitable

[Robbks]

DO you have them, or do you, perform intermediate oil changes..?

[THE SpecB]

DO you have them, or do you, perform intermediate oil changes..?

No I don't Subaru do everything I've transfered to Victoria now so all history I have in log books but no plugs been done and service guy said I should do them but I'm under their guidance

[Shaheenis]

I would use genuine Platinum plugs. Iridiums crack easily with knock, never had an issue with platinums even in the old wagon which pinged itself through two engines.

Coppers are fine if you don't mind changing them every year or less which is a pain in these vehicles. Platinums will last you 100K but I got ripped at the mechanic who charged me $40 per plug + labour. I got mine done early at 100K because of a hesitation issue which turned out to be the factory tune hesitation feature which Matt promptly fixed with a tune. You don't need different plugs for higher performance..

[THE SpecB]

I would use genuine Platinum plugs. Iridiums crack easily with knock, never had an issue with platinums even in the old wagon which pinged itself through two engines.

Coppers are fine if you don't mind changing them every year or less which is a pain in these vehicles. Platinums will last you 100K but I got ripped at the mechanic who charged me $40 per plug + labour. I got mine done early at 100K because of a hesitation issue which turned out to be the factory tune hesitation feature which Matt promptly fixed with a tune. You don't need different plugs for higher performance..

Thanks Tim so my plugs at present are original never been changed. Do I assume Subaru will put in these platinum plugs you talk off or do I ask them?

[Shaheenis]

Any reputable service agent SHOULD put them in but just ask the question to make sure. Standard issue for GTB are platinum plugs which don't get replaced until 115K according to service manual.

[THE SpecB]

Any reputable service agent SHOULD put them in but just ask the question to make sure. Standard issue for GTB are platinum plugs which don't get replaced until 115K according to service manual.

Ok will ensure service replace with platium any cost I should be paying without being ripped off ?

[THE SpecB]

Does anyone know the stock plug number and type that's in the GTB?

[kiwigene]

Does anyone know the stock plug number and type that's in the GTB?

It's in your owners manual.

SILFR6A (NGK)

[dr20t]

Here is my advice on plugs. Do with it what you will:

Platinums have long life, medium spark
Iridiums have medium life, strong spark
Copper has short life, strongest spark

Given how much of a pain it is to swap plugs, using longer life plugs makes sense where it doesn't compromise engine durability or safety.

Stock: Iridium lfr6aix gapped to 0.8mm
Mild setup 98 fuel : lfr6aix gapped to 0.8mm
E85: ILFR6B - iridium gapped to 0.8mm
Wild setup. 98 fuel - lfr7aix laser iridium one step colder gapped to 0.80mm for <25psi and 0.75 for over 25psi
E85: Lfr6a part number 6668 - copper and replace every 10,000kms and gapped same as above
but if over 30psi 0.7mm gap may be needed. Extremely important to use 6668 part number


Mick

[THE SpecB]

Here is my advice on plugs. Do with it what you will:

Platinums have long life, medium spark
Iridiums have medium life, strong spark
Copper has short life, strongest spark

Given how much of a pain it is to swap plugs, using longer life plugs makes sense where it doesn't compromise engine durability or safety.

Stock: Iridium lfr6aix gapped to 0.8mm
Mild setup 98 fuel : lfr6aix gapped to 0.8mm
E85: ILFR6B - iridium gapped to 0.8mm
Wild setup. 98 fuel - lfr7aix laser iridium one step colder gapped to 0.80mm for <25psi and 0.75 for over 25psi
E85: Lfr6a part number 6668 - copper and replace every 10,000kms and gapped same as above
but if over 30psi 0.7mm gap may be needed. Extremely important to use 6668 part number


Mick

Thanks Mick so even the stock plugs platinum is good enough for a tuned GTB?