No, not another question on the oil filter part number.
Being new to Porsche, I am wondering why Porsche still uses the filter in a reusable cannister design? Practically the entire industry has gone to the spin-on, disposable cannister. Why not Porsche?
Last one I had like that was my 1980 TR7. And I converted that to a spin-on.
Anyone have any ideas. Other than the cynical "well it gives them a chance to sell another Porsche part when it goes bad."
One reason is you can torque them down to a spec.
Actually, it's not a case of Porsche "still" using a replaceable filter element. It's more a question of "why are they shifting over" to using a separate element in a reusable canister. If you look at older 911s, you'll see they use a standard disposable can filter.
The reasons , I believe, are cost and environmental. First, the element is virtually the same whether or not it's housed in a steel can, so the element by itself is cheaper without the can. Second, there's less waste material since you are only replacing the element and reusing the can. It's also easier to get waste oil out of the element (for disposal) when the element is not wrapped in a can.
Personally, I like the way Porsche implemented the filter on the CS. I changed my oil last Friday, and that was the cleanest filter removal I've ever done (all of the ones with disposable cans leak oil as soon as the seal is broken, regardless of orientation). I used to own an '87 RX-7 that had the filter mounted upside down (the mounting flange faced up) -- it was impossible to remove the filter without making a huge mess.
If that matters, a spin on filter can also be torqued to a spec. if (as most do) it has flats for a filter wrench. Obviously, that's not a real problem since of the millions of no leak filter changes I'll bet almost none are torqued. Porsche has a torque spec. for the filter case so it's tight enough to seal properly, but not so tight the plastic case breaks.
What BillC said on the other points. Both oil filters on my 993 were metal spin ons. If I'm not mistaken, that vintage was the last Porsche to use metal filters.
I too just changed my CS oil & other than apprehension about refilling inside the car, it was a fast, clean & simple process.
Really the biggest difference is environmental. As mentioned, most spin off type filters trap oil inside, and where do those used up filters go? Most people just through them away in their trash so they go the dump or local landfill to leak their oil into the environment. I don't even want to imagine how many used filters are improperly disposed of.
Remember, the Germans are far ahead of us on the environmental awareness curve. I personally applaud them for taking this angle and wish every other car manufacturer would too.
Mazda has started using the cannister design on their 2.3L engine. My wife's Mazda3 is equipped with one.
