Thread: Early D4 Light bar in the top grill section

Take your grille out and you will find that mine isn't stopping any air flow. It sits above the radiator, as long as you use a single row bar like mine is.

Originally Posted by ytt105

Take your grille out and you will find that mine isn't stopping any air flow. It sits above the radiator, as long as you use a single row bar like mine is.

It doesn’t exactly work that way. The radiator system and front end is sealed and designed to be pressurised. Any air that enters the grill is forced through the radiator or maintains high pressure to force air through. Reducing the inlet size decreases the pressure and subsequent cooling effect. Whether there is surplus capacity in the grills for what can get through the radiator (and thus causes high enough pressure for flow around and under the car) is the guessing game. I guess you’ve shown that for YOUR usage it’s ok. Disclaimer being for those using their complete cooling capacity towing in high temps, it may cause issues.

I would think if the minimal amount of 'less air through the grille via the top slot' was a problem, then the cooling system has been under-designed.

Certainly not my experience in this D4 or my previous D3 that had bullbar, twin HID lights and an LED bar, towing 2 - 2.5t tintent up north.