Carpokes Porsche Forum

O875 wrote: Sat May 30, 2026 11:29 pm Part of the changing the oil before it's stored idea is that if you've used up the anti-corrosion additives then leaving the old oil on the bearings in that state isn't helping the engine. Better to store the engine with fresh additives, including the anti-corrosion ones.

Been enjoying this discussion. I'm trying to work out the best option at the moment, for a climate that sometimes exceeds 35℃. I'll probably go up to the over 35℃ range with the oil, just in case.

Makes all the sense in the world, I knew there was more to it, just couldn't remember all the talking points when I replied yesterday, thanks for the additional info.

From my simplistic "regular guy" point of view, oil changes are relatively inexpensive and DIY friendly in most cases, so anything we can do to stack the deck in favor of minimizing long term issues is worth exploring.

Of course, when it comes to the 997, I pay "the guy" to do the oil change simply because it is a little bit of a PITA to get right. As much as people talk about the 997 being the "last mostly analog 911" the one thing they should have left "analog" was a damn dipstick, it doesn't have one. It relies on a digital readout on oil level and it takes a long time to get it to actually read the level correctly as the oil has to drain all the way down to the pan and everyone fills to just under the fill line for a million reasons I cannot recall but overfilling the slightest bit is like touching the third rail.......so I'll pay the guy with the 911 and DIY for the 924S........again, first world problems.

Wix Filter are owned by Mann+Hummel, a German Filtration Worldwide Manufacturer and many of us have used these filters for a very long time. They used to make all of the NAPA Gold Filters but that is no longer the case. Wix also worked with SRT/MoPar for the performance oil filters for Vipers and the SRT lineup, so there are solid examples of high quality filters by this family owned manufacturer. Just a heads up if you loved NAPA Gold filters, you might just pick up a Wix one now to get what you have been using.

Well, Mahle filter and removal tool on order with some crush washers.

Picked up some Mobil 1 15W 50 today at Wally World. So in the next couple weeks I can bang out an oil change and run the Mobil 1 the remainder of the summer.

In between rain drops I gave the car a quick wash for giggles.

Appreciate some good oil discussion, Carpokes is really great when it comes to having an actual adult conversation that would send other forums into snarky fits of keyboard machismo...... Cheers.

This stuff dropped my oil temp from from +/- 220° to +/- 195°.
Raised oil pressure a little bit, water temp dropped too.
ZDDP over 1500ppm.
Specifically for air cooled engines, Gibbs says can run it in watercooled too.
Never thought I'd buy in to beautique oil marketing, but this stuff works.
OEM filter only, I think they are Mann.

WillyDaP wrote: Sun May 31, 2026 4:24 am Wix Filter are owned by Mann+Hummel, a German Filtration Worldwide Manufacturer and many of us have used these filters for a very long time. They used to make all of the NAPA Gold Filters but that is no longer the case. Wix also worked with SRT/MoPar for the performance oil filters for Vipers and the SRT lineup, so there are solid examples of high quality filters by this family owned manufacturer. Just a heads up if you loved NAPA Gold filters, you might just pick up a Wix one now to get what you have been using.

LN Engineering has done oil filter specific testing on WIX oil filters . Their testing shows Wix filters made in the US and Mexico are excellent quality . However Wix filters made in China are lesser quality and they do not recommend them . To the point that they visually inspect every filter they order . Their distributor now screens for them before shipment . Moral of the story , buy Wix filters made in the US or Mexico .

They also build many filters in Poland and they are of high quality also and it is no surprise corners are cut when being built in China. Purolator is also made by the same parent company, by the way.

Motul 15w50

Baldwin is also an excellent quality oil filter .

I've just learned that there is an even taller variant of the same filter than the 964 one, namely Mahle OC46 from a 928, it should also fit our cars fine. Anyone have any experience on this?

Edit. Here's a cross reference list of the same filter across different brands:

ACDelco X 4056 E
ALCO FILTER SP 1095
AMC Filter FOF 10034
BECK/ARNLEY 041 8138
BOSCH 0 451 103 215
CHAMP PH 915
ELOFIC EXL 703
FIL FILTER ZP 3026
FLEETGUARD LF1611 LF16111
FRAM PH6583
GUD FILTERS Z 401
KNECHT AW 73
LUBERFINER PH 915
MAHLE OC 46
MANN-FILTER W 730
PORSCHE 928 107 201 03 928 107 201 04 928 107 201 05 928 107 201 07
PUROLATOR L 17256 PC 251
SCT - MANNOL SM 825
SF FILTER SP 4472

Edit2. The 928 filter supposedly doesn't have the required drainback valve the 944 filters and presumably the 964 filters have, so that would prevent us from using them, anyone able to confirm this?

I go back and forth between Mobil 1 15w-50 Synththetic and Valvoline VR1 20w-50 Synthetic depending on a very scientific combination of what part of late spring/summer/early fall it is, whether I have upcoming track days planned, and how I'm feeling about all of those things. Both have been great in my experience and both have a relatively high amount of ZDDP for our flat tappets (the VR1 a bit more than the Mobil 1). The Mobil 1 is awesome because it's relatively cheap and really widely available.

For filters, I have a shelf full of Mahle, Hengst, Mann, and now Purolator L30165 filters since Rock Auto has them on markdown for under $4/each. Again, I change the filters probably more often than I need to because of semi-regular track use, but the Purolators seem to be of high enough quality and the description claims there is a drainback valve and bypass relief valve like the OEMs. They're also red, which matches the color of my car.