Why do people put flat boxes on the grill of their cars/trucks when it is cold out?

Question

I see this a lot, and nobody I asked gives an answer that makes any sense. Do you guys know?

Answer 1

first used by large diesel trucks, commonly referred to as a 'winter front'; the theory behind them is they partialy block the radiator opening, decreasing the airflow through the radiator and allowing for a faster warmup in cold weather.
Some people with gas powered cars and trucks have adopted this although a properly operating cooling system dosent need such drastic measures.

Answer 2

because they are trying to get more heat when the thermostat is probably stuck open and the prestone keeps going through the rad and cooling off all the time. todays cars never ever need to block the rad, as the thermostat, cooling sensor and rad fan do the job. if the heat range is too low the computer will send the wrong info for the right fuel mixture. ie less gas milage. if you dont have enough heat inside the car, check besides the thermostat the heater core which may be blocked. this can be checked with a laser termometer.one last thing is that if the thermostat is working right. the day the temp goes way up you may over heat. the bottom line is you would be interfering with a balanced system, a fools errand. yes diesel engines take longer but will reach proper temp

Answer 3

It's a throw back to the old days when cars had fans mounted on the engine that ran continuously while the engine was running. This caused the coolant to cool too much as it passed through the radiator, which, in turn, caused too much heat loss in the cooling system in cold weather. Blcking the rad with cardboard reduced the air cirulation through the rad causing it to retain more heat. The eend effect was more heat to the interior heater and warmer passengers.
Now, cars no longer have fans attached to the engine that run all the while the engine runs. They have electric, thermostatically controlled, fans that come on only when the coolant reaches a certain, preset, temperature. So putting cardboard on the front no longer has any real effect on temperature, though it can make the electric fan turn on more often. Besides, cardboard is ugly.

Answer 4

I have a 1991 Dodge Diesel Truck. When its really cold out, then engine never really warms up, and my heat is luke warm. I have replaced everything cooling related, and even replaced the thermostat with a Cummins OEM thermo, at $40...ouch. I believe in my case, the radiator is TOO big for the engine, and its overcooling. If I cover the radiator 1/2 way it gets right to operating temp.

On the other hand, most people install cardboard as a bandaid, either they have a stuck(open) thermostat, so the engine never heats up. They have a bad waterpump that wont circulated proper coolant through the heater core, or the heater core is plugged up, and its bypassing most of what area is needed for your heater. Thus if you make the engine run hotter than it should, youll get good heat.

9 chances outa 10, unless in oddball situations its not needed.

Answer 5

i'm not 100% sure but this is what i think

see when your driveing down the road when it's cold out
that cold air goes tho the radaitor and cooles down the water and that cooles down the motor what cooles down the heat in the car so maybe if u put a box thier that keeps some cold air from geting in thier

hope this helps

Answer 6

It helps to keep the cold air off the radiator and the engin heates up quicker and so you can get heat out of the heater quicker and engin works better quicker.

Answer 7

They do it to reduce the amount of cold air moving through their radiator. They do this so the engine heats up and they get more heat inside the car.

Answer 8

it cuts the airflow to the engine and heats it up faster, you manly see this on semi trucks when they are running through the northern region during the winter

Answer 9

some need the thermostat replaced.. the motor is running cold and they are to cheap or lazy to fix it....a cold motor wreckes your millage and is bad for it.