Spark Plugs - Condition of Engine?

[BeastPower]

I have included some photos of the spark plugs that I removed from my M3. They are not old plugs, but I am curious if anyone here can shed some light on the condition of my engine based on these photos:







Thanks, Daniel.

[AlpineRunner]

From what I know they look good to me. Having some carbon around the base shows it's not lean and having a whiteish ground piece means it's not too rich. However looking at plugs is not the greatest method of diagnosing because they will always show the condition of the engine right before it was shut down, which is usually at idle.

[Ironhead]

Daniel, Alpine is right. Plug reading is more an art than a science. You have to run the engine in the range you want to test, then shut it off and coast to a stop to really learn anything. Even then, unless things are grossly wrong it is hard to draw too many conclusions from plugs....

Your plugs look more or less "normal", but as Alpine said it really only tells you that the engine is running OK at idle.....

I think plug reading is a relic from the days of carburetors and AFRs that were only good enough to make the engine run. Now with computer controlled engines and all, I think plug reading is sort of outdated unless you are looking for things like oil in the cylinders, etc.

A good wideband O2 meter will tell you much more about the mixture than the plugs can.

[BeastPower]

Thanks guys! I appreciate the feedback. I didn't really expect to learn anything terribly interesting, but it is nice to know that there isn't anything that looks catastrophic. In rebuilding the car, I am working my way from the engine's electrical system, cooling system, suspension, drivetrain, brakes, then interior rust, exterior rust, cosmetics, and lastly will delve into the engine's condition. As long as the car seems to be running well, I prefer to handle it last.

I appreciate the help. Cheers, Daniel.