@Mike373- Just so you know- the VDO cht gauge is not temperature compensated (I think that's what you call it) so it reads low above 70°F and high below 70, with the further from 70 the ambient temperature is the bigger the error. 70°F is the only place where it is close to accurate. The Dakota Digital gauge that Michael runs is a quality piece, and there are a couple others, but they are not cheap. And as Danny said, the only place to get a truly accurate (and in real time) combustion chamber reading is from right under a spark plug.