[Piwoslaw]

Wow! That upper grille block rocks! Here are some observations from today's ride (city driving around 50 km/h, some highway at 60-70 km/h):
The outdoor temperature was around 0-1°C, light drizzle. When leaving home the coolant temperature was pre-warmed to 40°C. After the first 10km from home the coolant temperature was stable at the usual 78°C (my normal temp, rarely more), then 2-3 stop lights and I was on the highway (70 km/h). Suddenly I noticed the temperature was 93°C! I never get more than 82-84°C after some stop & go and/or overpasses before the highway. When I slowed down the temperature dropped very slowly (much slower than usual) to about 88°C.

Also, intake air temps are way up: Usually they are 2-4°C above ambient, but today they were 15°C above! I'll add that my intake air temperature sensor is before the turbo, so opening the lower grille block's intercooler side won't change the reading. One day I'll have to put a temp sensor before the intake manifold to see how much of a difference blocking/unblocking the IC makes.

It looks like the new grille block's real advantage is not just blocking the radiator, but keeping air out of the engine bay.