Spark Plugs = reddish tan, What's normal?
 

My NGK BKR7E-QUP (1 step colder & JCW Plug) is showing reddish-tan color (almost rusty). The center electrode looks glazed too.

Is this normal? Am I running too lean? or hot?

My OEM and NGK Iridiums 7E-IX prior to my tune were both greyish-tan in color.

I would like to add that I added a 1/4 bottle of NOS Octane Booster.

we pulled a bunch of the plugs on cars up there at the tune and they had this color to them. The locals said it was in the gas

i think it has something to do with the summer blend gas...i got a bit of a reddish tint to my plugs but according to the scan guage and everything else its running just fine

If it's like this... np. I've seen racing fuel make them red too. Maybe it was the OB ?

Attachment 36412

It is more than that. It's all over. I am running a tank without the octane booster & see if it will change.

take a picture of the plugs and post it please

Sounds like the the gas has an additive called MMT in it. Or the people are running a gas additive with MMT in it. This is pulled off a subie forum. They were talking about a similar issue

(Start Quote)
"Quick easy way to tell. If you have run the unleaded concentrate, pull a spark plug. If it has a reddish color, (looks kinda like a rust stain) then the concentrate has MMT in it."
(end quote)

(another interesting note)
MMT IN GASOLINE
MMT is a manganese-containing metallic additive that is blended into some gasoline to increase octane. Gasoline blended with MMT provide no performance advantage beyond gasoline of the same octane number without MMT. Gasoline blended with MMT reduce spark plug life and reduce emission system performance in some vehicles. We recommend that gasoline free of MMT be used in your vehicle. The MMT content of gasoline may not be indicated on the gasoline pump; therefore, you should ask your gasoline retailer whether or not his/her gasoline contains MMT.

It is even more important to look for gasoline without MMT in Canada because MMT can be used at levels higher than allowed in the United States. MMT is prohibited in Federal and California reformulated gasoline.

It looks like the gas additive NOS contains MMT. Most likely the cause of your red color

http://www.essexracing.com/product_i...roducts_id=350

Here is the picture which is OK now, perfect color. It must be that NOS OB!
Thanks to everybody.
Cheers!

My Camera is lousy! honestly, the color is no longer reddish tan but greyish tan!