Toilet Paper Oil Filter

The line between novelty and true advancement in technology is very fine. Razor-thin, in fact. That’s why a lot of products that could make our lives easier or better often get scoffed at by those who don’t understand them completely. On the other end of the spectrum are items promising the world for $19.95.

Somewhere in between is the Frantz oil filter.

Haven’t heard of it? I hadn’t either, until a member of one of the Corvair forums I follow put out a for-sale ad that caught my eye. A silver canister with two hose-barb fittings and an angle mounting bracket, along with what looked like a little adapter. Anytime I’m unable to quickly identify a part, I spiral rapidly down a hole of research. A Corvair piece that I hadn’t seen? Gotta know about it. Luckily, the seller didn’t leave folks guessing. It was a Frantz oil filter, with the rare, Corvair-specific adapter for easy install.

Neat—but why did it exist? What problem does this fix? Was it a … snake-oil filter?

Part of what had caught my eye in the listing was a roll of toilet paper used to prop up the adapter for photos. Turns out, as odd as it looked, the roll was supposed to be there. The Frantz filter is marketed to either supplement or replace a factory-fit oil filtration system with toilet paper. As strange as the idea sounds, toilet paper as an oil filter is not crazy.

After all, the vast majority of oil filters are paper media, strands of fiber woven together create a perfect net to catch particulates. A pleated paper element comprises the core of most spin-on cartridges, and it makes sense to change out the paper rather than the whole element. The Frantz company decided to utilize something every car owner had on hand: toilet paper.

By sizing the canister just right, Frantz could direct oil through a core of “filter material” nearly 4.5 inches in diameter before allowing the oil to exit and return to the engine. The roll provides markedly more filtering material than a pleated-element insert does. Frantz also claims that the toilet paper is constructed with a finer mesh and thus can trap even smaller particulates than a traditional filter.

That isn’t hard to believe. Anyone who has taken apart an oil filter to see what nastiness it was catching from inside their engine can see the filter media is fairly thin. It feels a bit like loose cardboard. If you unwind a roll of toilet paper, you’ll get about 75 feet of filter material. Seventy-five feet. That should filter your oil well for a long time—and it can. Sort of.

The trouble relates to how oil degrades in your engine. Sure, debris and junk that finds its way past gaskets or piston rings needs to be trapped, but oil itself degrades at the chemical level. Heat and pressure conspire to reduce the effectiveness of the many additives in modern oil, regardless of the system’s physical filtration level.

Frantz oil filter with dirty TP roll
New roll on the left, used roll (out of the filter) on the right. Frantz

Oil becomes acidic because of the byproducts of combustion that leak past piston rings and valve seals. Even if you removed all the debris floating in your oil, you would still need to change it on a regular basis. If your oil gets acidic enough, it can damage bearings and other surfaces just as badly as if it weren’t there or if it were contaminated with chunks of stuff. Only changing the oil can prevent the breakdown of those chemical compounds. If you are changing oil often enough to keep that degradation at bay, then do you really need a supplemental filter to remove every last floating piece of junk? That’s for you to decide.

I had to have the Frantz filter for my garage. I messaged the seller, then sent over some money and my shipping address. It won’t be installed on the Corvair, but I’m not going to call the Frantz a gimmick, either. It’s a fun conversation piece that I can mount behind the workbench and maybe even use as a storage canister for hardware or little bits that need to stay safe while I’m working on a project. After all, what gadget is more interesting than one meant to equip your vintage ride with a roll of toilet paper? I can’t think of much else.

Frantz oil filter with TP
Kyle Smith