[x260_4_Me]

The black plastic I'm referring to looks like shutter. I don't see it open up when car is idle. Does this open up at high speed or does it stays like that blocking air from the radiator? But i never have had an engine overheat before, ever, just curios why it is like that? Is it to protect the radiator from bugs or road debris? I guess?

 

[MrKis]

The shutter is there to manage the engine temp more efficiently.
It will warm up quicker and as a result lower emissions and improve efficiency.
It may even close at higher speed improving aerodynamics when cooling air is plentiful.

 

[chrisjp]

I have this shutter system on my XE. Although I'm sure it probably ekes a few fractions of a mpg fuel consumption improvement, it is, IMHO, yet another thing to go wrong - and with engine overheating a serious consequence of this.

 

[x260_4_Me]

This new engineering technology is beyond me. Now I know. Thanks for the replies fellow members.