[911monty]

Are we taking into account the fact that the oil cooler is dumping BTUs into the water system?
I ask this because Last year I installed new WP, LT stat new hoses AND the larger S oil cooler on my 2.5 base. At the same time I removed both radiators and had boiled out and flushed. Now I have been watching the temp display on the AC panel religiously.
As Rick3000 says below 75 deg ambient the temp gauge at cruise speeds is at the 180 hash mark. Once temps move up the temp also increases. When I get into the hilly twisties the temps rapidly climb and will get to the right 0 edge, approx. 213 deg.
I think the additional BTUs (and ESPECIALLY the larger S cooler) due to work load rapidly heat the water the radiators are trying to get rid of. The LT stat is wide open with full flow to the rads. At this point if the radiators are not 100% you are fighting a losing battle.
My theory is this, it is only a theory. Increasing RPM on say the freeway only increases the BTUs from the coolant and the engine oil. I found that running in 6th with the resultant decrease lowers BTU output and the engine cools.
I also think that part of what stop and go does is lessens the air flow across the sump. If you think about the 100 deg differential between the 200 deg oil in the sump and 100 deg air, a considerable amount of BTUs are being swept away. I think a finned sump cover would be awesome.
I also have concerns about an engine with a LT stat, and S cooler in the winter. This may be due to my old school thinking but If oil in sump never gets above 180 how does it boil off the contaminates? Water boils off at 212 deg. Now at 6"WC vac (sump pressure) water boils at approx 195 deg. Is this why our cars have a 195 deg stat stock?

edit: Randall could your increasing temps be due to the increased humidity you guys have this time of year? Humid air has less effective heat adsorption?