Which spark plugs/

[Geodesiq]

There are a ton of different spark plugs listed for the G1 Insight. Which ones are best for mileage?

Auto Parts and Accessories Catalog - Spark Plug

[02insight]

The insight uses specialized indexed spark plugs. You have to remove your coil-pack, and see what letter is stamped on the block (A/B/C or D), Majority of the time it is usually "B", but its is best to check before ordering them. And you can only order them from Honda. Aftermarket plugs will technically work, but wont be indexed and may have a different kind of tip.

Here is more info about the indexing of the sparkplugs on the insight:
InsightCentral.net - Encyclopedia - Honda Insight Iridium Spark Plugs


Cheapest I have found are from g1parts.com at only $13.96 each. It may sound expensive, but really in the long run it is worth it since these last a really long time.

Here are the part numbers of each plug, based on their indexing:

12290-PHM-A01 A
12291-PHM-A01 B
12292-PHM-A01 C
12293-PHM-A01 D

[JimIsbell]

I bought 6 cheap plugs that were not indexed. Then I indexed them myself and found 4 of the 6 would index at "B" which was what mine were. This cost me a lot less than buying Honda plugs.

[Geodesiq]

mod: Please delete.

[Velociraptor]

Originally Posted by Geodesiq

There are 3 cylinders. How come there are 4 plugs (A, B, C, D)?

I think this will explain:

InsightCentral.net - Encyclopedia - Honda Insight Iridium Spark Plugs

[JimIsbell]

OMG, do we really need to explain this. With three plugs there could be A Thru Z if you wanted to index them every 12 degrees!!!!

[Geodesiq]

Originally Posted by JimIsbell

OMG, do we really need to explain this.

Only if you want to. If not then just shut up. Or isn't that an option for you?

[JimIsbell]

Originally Posted by Geodesiq

Only if you want to. If not then just shut up. Or isn't that an option for you?

OOOOO, testy too!!! Cummon, it was a strange question.......................................

[gsfent]

For the OP, it is suggested that there is about a 90 degree range of coverage of where the plug electrode is to maximize performance/mileage. So 4 plugs cover the 360 degrees.

I don't know that non indexed plugs would lose much, but given how often you have to change plugs (and there are only 3), it is just not that big of a deal to go indexed plugs.

Regards,
Jerry

[Roen]

What tools (i.e. sockets) do I need to take off the engine cover and coil packs to find out which letter I need for the spark plugs? Since I've never done this before, how long should I expect to need to do this?