I bumped into this the other day, and thought I'd share it. I've never been one to accurately read a spark plug unless it's flippin' obvious... http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

 

Comprehensive, that one is. I really like reading plugs over sensors etc. Sensors are just reading the results of combustion from OUTSIDE the chamber, gas temp, oxygen content etc. But plug reading is checking the results of combustion from inside the chamber, and can tell you all sorts of things about what's happening during combustion. Wide band tuning is nice for EFI or carb though. I've heard that Fel Pro has been doing research on new head gaskets with sensors in the fire ring that can read the events of combustion AS THEY OCCUR. Evidently it has built in presure, temp etc sensors and sends info to the ECM about what is REALLY happening with combustion, rather than simply reading the after effects. It's for future cars designed to work with it, but the way things are looking, by the time it's implemented, combustion engines may have already gone the way of the Dodo bird. It'd be a revolutionary step though, since the ECM could tune for maximum cylinder pressure, and thus maximum power.

 

great find!