I know that the grill opening size has a great influence on speed, fuel economy, etc. I recently blocked off the grill opening that is just above the bumper with gorilla tape. Driving around town, the DIC indicates 192, which is 2 degrees cooler than normal. This I can't explain. I took a round trip from Tulsa to Houston last week. The outside air temperature, according to the DIC, hit a high of 107 degrees. I kept the DIC reading the engine temperature to be sure I didn't overheat. I saw one temperature spike of 207, but it immediately dropped back to 196. I saw an increase of 2.5 to 3 MPG over normal. I usually get about 30 on such a trip, but one tank ran 33.2 MPG. I plan to put something that will force the air going through the botton grill to go through the radiator. If this adds additional cooling, I will try blocking off the top grill.

 

Cool. I wouldnt do it.

 

I would not recommend this personally sounds like a bad Idea. Numbers dont lie but sounds like a bad Idea

 

unless your trying to hit 200 mph just leave the ****** thing alone

 

hopefully some one chimes in with some usefull input. in for that.

 

3.2 MPG by taping over that small an area of grille? I think I'd want to see those results consistently repeated a few times before I'd be convinced.

 

Did you run the a/c the whole time? That forces the fan(s) on full time.
The real test from a cooling standpoint would be slow moving stop and go without a/c running.

I wouldn't do it. Like a/c in cars (usually more than enough capacity to cool).... they put that capacity there for a reason. If you block it it might not be there when you really need it. Like if your insurance company ditched you when ready to make a claim. Trust me when I say I'm very certain GMs' main concern was economy and built high performance around that number one priority.
If the grill opening wasn't ABSOLUTELY necessary it couldn't be there.

Even if it always works you will be working components overtime. Several things rely on that airflow for cooling.

 

I did have the AC on at all times.

 

I just went and looked at my car. It appears the upper opening might be better if you're going to block one off. The lower opening above the bumper feeds directly to the A/C condenser and radiator. The upper opening looks like it lets air into the engine area which is usually bad for aero.

Dog

 

I thought this would be the dumbest post ever when I read the title...................and I was right.

 

why is this so dumb? trying to be a little more efficient? maybe the whole grille is a bad idea. but the portion above the bowtie might not be. if done right (not with tape) it wouldnt look bad. and its not like he's duct taping every seam on the front end of the car. Im in for this idea. I would like to see pics too.

 

if you wanna go a step further, take out the rubber on the cowl in the back of the engine bay... it will let the air out from under the hood, should help as well

 

hypermilers typicaly do this. They will seal around the headlights as well. But this is not a hypermiler car it is a performance car so I don't see the point in ruining the look of the car and posibly increasing IATs and coolant temps.

 

unless your trying to hit 150-200mph leave it.

 

Isn't that a low pressure area? I would think it would suck air INTO the engine bay, not out.