nrp wrote:

Each of us has a hot button, but I'd be willing to bet that one cold
start with marginal preheat would drive the metal analysis way off the
chart. I have no problem with looking for a trend, but consider it for
feedback to your operating guidelines too.

No cold starts here, at least assuming my Tanis heater is working
correctly.

I am religious about plugging in the Tanis heater both at my home T-hangar
and at my destination hangar if temperatures drop below 50 degrees F or so
(this also prevents having to run the engine for a longer than normal time
on the ground to bring the oil temperature up to the minimum of 120 for
takeoff).

When temps fall below 30 degrees F, I throw on the prop and cowling cover
that I purchased a couple of years ago from Kennon in addition to the Tanis
heater.

--
Peter