View Full Version : Form without function?

09-14-2012, 06:54 AM
I've always been someone who's disliked "decoration" on automobiles.
By "decoration"...I mean a feature built into a design...like the "air intake" ducts where the fog lamps sit on the CX-5.
On my Porsche C4S...these intakes are there to allow air to enter and cool the breaks and aid aerodynamics...

Anyone have any theories as to why these ducts are just "implied" in the CX-5...instead of actually allowing air to pass through?

I'm being very picky here...since my CX-5 has a coefficient of drag not far off of my Porsche (.033 and .029 respectively).
I guess I just prefer functional a feature to the suggestion of one.


09-14-2012, 08:43 AM
On the auto trans 2010 mazda3 the drivers side fog light honeycomb actually was functional and behind it sat a transmission cooler. I believe the next revision of the car deleted the cooler as a cost savings measure and they just made the honey comb solid.

Perhaps its there in case they need to add something in the future they could without a redesign of the bumber?

09-14-2012, 09:53 AM
making them solid also aids in cutting down drag...

09-14-2012, 01:04 PM
Fake vents are featured on most of Mazda's fleet.

Especially the faux vents/ducting in the fog light surrounds (and other areas). My Speed6 has them as well. Though, interestingly the Speed6's PS cooler sits right behind this fake honeycomb vent on the driver's side. Not sure why they didn't just make it functional to supply air to the cooler. Otherwise, their vehicles generally aren't used for road racing, and don't have big brakes that need additional air cooling.

The plastic belly tray/pan they also put on their cars assists in creating high/low pressure conditions, which helps draw air in and around the engine bay and through the air dam and radiator.

So, why they include they fake vents, I don't know. Literally just for aesthetics, I guess. Seems like most auto manufacturers are doing this though, not just Mazda.

09-14-2012, 04:50 PM
It's a non-issue for me, I never even noticed the area around the fog lights was supposed to look like a (fake) vent.

I've owned 3 Porsches and their aerodynamics are nothing special, especially the drooping rear end which requires an electric spoiler to minimize that problems in wind tunnel that retro shape creates (that drooping rear shape is form without function). Most sports cars sacrafice the aero cd number for extra downforce and drag from fitment of huge wheels and tires. I do like how Porsche was one of the first to create underbody fairings for improved aerodynamics. My 2 modern sport sedans (Lexus and Mercedes) have better aero (cd) numbers than a typical Boxster/911.

I do dislike big fake vents, like fake hood scoops.

09-14-2012, 05:11 PM
Have to agree that the fake little honeycomb grills are so subtle that I haven't really ever even thought about them. The fake vents/scoops on the older Mustangs were comical, as are the fake vents on the hood of the newly redesigned Hyundai Genesis Coupe. I just don't get implementing them. It's like showing off a temporary tattoo.

09-15-2012, 08:33 PM
They are $75 each for the ones with fog lights, they just snap in and out, so if you want to modify them you have that option too. If you wanted to fill the honeycomb with foam and fiberglass over them then have them painted body color or what ever floats your boat, but it does not make them functional as vents either way..... I am more bothered by the large honeycomb holes in the upper grille and the huge holes in the lower grille, lots of stuff gets in there to ding up the fins on the coolers, sort of defeating the function of having a grille... Unfortunately, I believe that the marketing department got the heads up on this over the actual mechanical design department, I can just hear a "no, that looks really cool, lets do that" statement from someone that drives the latest flashy lease vehicle they can afford.......such is marketing IMHO

09-15-2012, 08:45 PM
Since we are comparing Porsche aero numbers to a Mazda SUV (CX-5), it should be mentioned the Porsche SUV (Cayenne) has .35cd, not as good as the common CX-5.

09-15-2012, 11:26 PM
I am more bothered by the large honeycomb holes in the upper grille and the huge holes in the lower grille, lots of stuff gets in there to ding up the fins on the coolers, sort of defeating the function of having a grille...

I think the large intake down low is for aero design flow to help with cf and down force at speed. They even plugged some of the grill up high to force air over the top of the car which will let more air in down low to reduce pressure under the car. My 2000 vet gets all its air down low below the bumper with a spring loaded air dam below the bumper just if front of the front wheels. The air comes in down low and goes up to the radiator which is mounted with a slant. This increases down force and moves more of the air over the top. If you look at the 2014 Mazda 6 it also has a lot of space down low for air intake. All this increases the need for a bug screen similar to the one I installed as listed in the How To section.

09-18-2012, 04:47 PM
The CX-5 does very well with the decoration in the wind tunnel, when compared to all SUVs for any price.