Grille block for fuel economy

A car can be made slightly more aerodynamic by blocking off unecessary grilles. This is a mode known as a grille block. This has a benefit for fuel economy as long as the car doesn’t end up overheating. I live in a cold climate so fortunately I don’t have to worry about that!

Creating the plates on the outside of the grille would add a marginal benefit but either way the air is forced to flow elsewherer ather than into the engine bay. This method keeps the standard look of the vehicle. In this method, air pressure will build up in the grilles slats before forcing it to “overflow” to the bonnet etc. Kind of like a bucket which must fill with water before it can overflow. I expect the difference would only be slight as this mod is minor anyway.

I just completed my grill blocks on my new saab. Here’s how I did it. First I removed the 3 grilles from the car:

I used polystyrene filled cardboard (used for signs etc) to make backing plates. I drew around the shape with a pen:

Then cut out the individual plates I needed:

Then I spraypainted the 3 plates in matt black to keep them hidden:

After a test-fitting:

I trimmed off any extra around the sides, using my knife:

I then used a hot glue-gun to secure the backing plates to the grills:

After about 20 seconds held in place they were secure:

I refitted all 3 grilles to the car:

and you would never even know they were there: