Thre reason Cadillac run the high temperatures is to make the Catalyic converter burn the emissions to pass the stringent laws, mainly in the US.
The disadvantage is that the intake manifold now is hot so this reduces performance, because the air is warmed as it passes through it, whereas cold air is the best, and especially in city driving the heat-sink effect is enormous, so when you nail it off the lights the performance is down, and if fuel quality is not so good you can get pinking.
By lowering the engine temperature, as I have done, does give better performance, and feels like driving on a cold night, even during a hot summers day in the city. The engine is not that cold, so ECM is not, or does not appear to be affecting the tuning of the engine. In fact I get slightly better fuel economy with normal driving.
Other advantages is that the oil temp is lower, which helps keep it together longer, plus the transmission oil runs slightly cooler, giving crisper changes.
I understand the reasons for not changing factory settings, and I normally totally agree, but in my case this has been enormously advantageous, but I must say, I live in Queensland Australia, and drive my car daily, we do not have the same stringent emission laws here, or at least they do not test them, so this needs to be considered where you live.
Guy
