Spark Plug Info

[tebbyj]

Well i thought i would make a thread to show people the information i have discovered about spark plugs.

As we all know most Subaru turbos specify NGK PRF6G or B (Article A) spark plugs as a standard replacement spark plug, these spark plugs are a top quality Laser Platinum OEM replacement plug. Because of this they come at OEM part prices ($30.99 each at super cheap auto) now despite these plugs being able to be used for a much longer service interval than a traditional copper plug i know many of you out there wont leave the plug in for the 100,000k service interval specified. It just doesn\'t seem right. and spending $120 on spark plugs that are designed to last double the time they will realistically stay in there seems like a waste of money so i decided to do some research into finding a cheaper alternative.

A

As it turns out NGK PFR6G plugs are exactly the same as as the standard NGK BKR6EIX (Article B)Iridium spark plugs (except for the materials the electrodes are made from platinum vs iridium) the dimensions, threads all exactly the same. and they even specify a longer 120k service interval over the platnuims

B

Now you think sweet! i can save some money and get these for my suby, they must be cheaper, and they are, by about $2 (SCA price $29.99). And about you think well thats a fat load of good, however BRK6EIX plugs are alot more readily available and if you shop around can be had for $60 for a set of four.

But not happy with this price i decided to do some more research and see what can be had for a reasonable price, you can get a NGK BKR6E copper plug for $7.50 but if anything this seems to far off the other end of the scale so.. i kept looking and thought.. What does Bosch have to offer.

So using a cross reference chart i found that Bosch offer a equivalent plug FR6DPX (Article C). This plug offers a 50,000k service interval, and is a platinum plug (the same as the original PFR6G). Better yet this is available at a very reasonable $43 for a set of 4 at SCA code P14-4.

C

Now i have herd good and bad things about Bosch spark-plugs, but have run these in my car for 250 kms now and had no trouble what so ever. So if you want to save yourself some money next plug change go bosch, will pull these out in a few thousand and see how they are wearing.

[Guest]

Bosch have been around for many moons but people love NGK regardless of price. Buy at autostop/asl/whatever theyre called where you are thats where super cheap and the like buy them anyway.

Tbh Ive found copper the best especially when playing with rich mixtures that foul plugs the iridiums are way more picky and foul easy. For the 20min it takes to swap plugs and for what it tells you about whats going on in your engine its good to have them out every so often anyway. Also copper are under $5 per plug.

Also read an interesting post on plugs the other day regarding protruding plugs. Iirc it was an evo with spark being blown out around 300wkw with tight gap. Went to the stock style rather than the protruded type and could run the recommended gap. Would have to check codes I was just going to worry about it next change which probably wont be in my ownership.

[Koom]

Aren\'t protruding type the standard and the non-protruding generally harder to find as they\'re not that common?

I\'ve got a set of 7 and 8 heat range plugs at home which are non protruding. The 8\'s are standard fitment on some sort of Aston Martin and are easy to find for decent price off Ebay UK.

[Guest]

Common as but I dont know how they sit in a sub/EJ head but works in mitzi.

[Guest]

Stock is BKR7E so not protruding. Evo is BPR7E iirc so yea not relevant info on CS unless you own a real car.

http://www.ngkspark.co.nz/spark-plugs/product-information/part-numbering-system

[tebbyj]

The Bosch ones are the non-protuding type, but i think you can get a protruding one unsure of the part # though.

[johnny5]

Ive been running the bosch equivalent for a while now and have had no problems what so ever not sure of the number but the equivalent of the pfr7g I think