Which Air Filter Really Makes the Best Coffee Filter?

OK, so K&N now has a commercial with a mechanic who puts a paper air filter in its place: inside the coffee machine. Apparently, K&N hasn’t heard of idiots who go and do exactly what your far-fetched commercial shows. Do they care about the children? Anyway, it’s not a very well-done commercial (not to get all Siskel and Eggbert on you guys), but it did get us thinking about, well, being those idiots who do what the far-fetched commercial says. This should be very fun, but in very poor taste…literally.

First up, the paper air filter, which we pulled out of my buddy’s Dodge just for fun. It’s been about, oh, 20,000 miles since it was last changed, during which time there were two gnat swarms and one huge wildfire—like snowing ashes and hard to breathe wildfire. The dingy paper was hard to tear out of the urethane frame, but we got it stuffed into place with even a couple of bee carcasses. We fired up the machine, scooped a couple of Yuban clumps in, and let ‘er rip. The results: terrible. Let’s just move on. We can’t tell if the solid bits are poorly filtered grounds or fire leavings.

K&N is next. We figured that if they’re going to brag about being a better air filter than a paper air filter when actually installed on a car, then it’s fair to compare the two in the coffee machine test. Cutting an acceptable piece out of a fresh K&N is a little tough, given the wire mesh and all. But, some tin snips helped us get the right shape filter. Of course, we had quite a bit of trouble getting coffee out of the machine. Since it’s pre-oiled, the filter tended to repel the coffee that should have been seeping down into the pot. Once we finally got a cupful, it was terrible. I spat it all over the guys and gagged, then threw up in my mouth a little bit.

The last one for the test is an AFE Pro-Guard 7 air filter. That’s 7 full layers of filter to stop little bits of coffee grinds from getting into the carafe. But, will the coffee even get past the thick cotton-gauze with the slick oiled coating? It did…through the top of the filter container. Sure, a few drops came out through the nozzle, but much more spilled out the top. It was a complete mess. But, it did make the best coffee of the three, given that it tasted like French roast with three pumps of Torani WD40 syrup. Yuck.

In other words, we’ve figured out that mimicking bad commercials due to summer boredom leads to puking, and to bad coffee. And some pissed-off parents when their morning brew reeks of automotive oil. But, we now know why K&N didn’t show their filters as the supreme coffee filter, though they tout themselves as the peak in filtration technology. Their coffee lost, and so did the paper filter’s. The AFE filter won, but, if it wouldn’t let coffee past, how’s it going to let more air past than a paper filter or K&N? We don’t really know—we’re not into testing things in their actual use.

Air filters like AFE filters don’t really make good non-automotive filters. Buyer beware. - David S. Brooks