I've seen on more than a few cars / trucks and even a few buses either card board covering the front grille, or a peice of what looked like vinyl on it.

What would the purpose of doing that be? My guess would be less air into the intake, for better gas mileage maybe?

If so, I may look into that, I've been getting crappy gas mileage the past 2 tanks, last fill up I was at 250 miles to the tank, this time I'm at about 80 miles for 2/3rd of the tank.

I need to look into a spell checker.

 

the grill isnt where air is brought in. so its got nothing to do with that. i think ive heard sumthin about those things letting the car heat up more/faster. so im guessin in the north thats a plus.

 

Well, I know that diesel engines in paticular do this for heat. Diesel's run good with heat whereas gas engines hate heat.

I know back in the day in High School, I asked the Bus garage Manager why they all had covers and he said it was for easier warm-up and better operating temperatures in the cold.

Also, alot of the county plows and vehicles in Michigan and in DC had them too -- for the same reason.

 

It allows the truck or car to warm up faster. That is all gas or deisel

 

Interesting, I'll have to try this out and see what happens.

 

I know I have seen some gas engines running around with the grill covers on, and I do understand that the grill is not the usual place for air intake to the engine -- but it does allow for air to get to the engine bay, thus providing some degree of cooling of the ambient temperature.

I would be afraid to cover too much of a gas engine and have it heat up during driving.

 

Yea mostly older v8 w/ carbs do this because they take long to warm up but you shouldn't cover the whole rad. on a gas motor

 

 

250 mi a tank isn't half bad. I just filled up at 245 and needed it BAD! So you're not far off from me.. Ah, but wait, you're a 4x2 w/ the 2.5L 4-banger.. uh, nevermind..

I'm not sure faster warmups would even really help your mileage that much. You've got to expect lower mileage in the winter on account of you letting the truck warm up longer and spending more time slip-sliding around. I know my milage has been terrible lately. I haven't crunched the numbers, but that one week where we had the two good storms right in a row I was in 4x a lot and probably rated ~150 miles on at least one tank..

 

When you first start, the coolant in the rad and engine are cold. The engine heats the coolant. The thermostat then opens and coolant flows to the rad. How can covering the rad cause the engine to heat up faster?
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We do this to get the vehicles to warm up. There has been times where I will start my truck, Let it warm up for 5 minutes, Drive 20 minutes into work and the thing will still be below normal temp. By covering the grille the truck will warm up MUCH quicker. Normaly the vehicles will not over heat. If they do get too hot the covers are easily removable. Some covers even have some snaps so you can adjust how much air comes in. If you guys need more details on this, let me know. I would be more then wiling to explain further... But the wife is calling for me.. so I gotta run!

 

Like Big John said, there isn't even coolant flowing through the radiator until the thermostat opens. The thermostat opens when the coolant around the engine block has reached what... 160 or 180 degrees? All this cover will do is make it go from warm to hot faster and maybe make it a little more hot. It will not decrease the time it takes to go from cold to warm.

 

The way it works is that by covering all or most of the part of the grill that's right in front of the radiator you get less cold air hitting the radiator as you drive down the road, because the covering obviously keeps the cold air from hitting the radiator. The more cold air that hits the radiator the more it cools down the coolant -- or, put another way, the less the coolant can warm up. People do it to get more heat out of the heater inside the passenger compartment. Driving down the road at a given speed is like having a wind of that speed hitting the vehicle when the vehicle is stopped. It used to be done more than it is now, because most new vehicles now have a good enough heater that it will heat up the passenger compartment just fine, even at 20 below or colder. It gets 20 below or colder every winter where I live and my Ranger's heater puts out plenty of heat at those temps with no covering over the grill.