mortymower

Yea, wix, stp, even fram has one in it so i think as long as its for the 944 then it will have the valve, (unless you buy it at the dollartree)

EdC

Anyone use a 928 filter? It is bigger than a stock 951.

mortymower

It is bigger, however, it is mounted vertically with the opening facing up in the 928, so there is no anti-drainback valve since you shut the engine off, the oil just stays in the filter (gravity). On the 951 the filter is mounted facing down at an angle so with that filter when you turn the motor off, all of the oil drains out (gravity). So when using this filter, when you first crank up you have no oil pressure until it fills that big filter up (10-20 sec).

LFA951

I've heard that we should stay away from 928 filters and stick with 951 filters...

2bridges

I would stay away from the filter for the underpowered twin engine (928)

Jfrahm

Any correct filter for the car should have the anti-drainback valve. An incorrect filter may not. I think the 928 filter might not have an anti-drainback valve and may not need one for the (mighty) engine for which it was designed.

The oil filter study was pretty interesting, however the info may not be very current now:
http://minimopar.knizefamily.net/oil...dy-german.html

Given that the OEM filter is not especially large (nor small) and the intervals are quite long (7500 Turbo, 15000 NA) I think it is wise to use a quality filter. The cheapo filters might have the same design, made in the same factory as a name brand one, but perhaps with less filter media and perhaps not as good a media quality.

For me the Purolator Premium Plus is good enough, the Napa Gold might be better but I do not go to NAPA that often. The Mahle is my usual filter. I like white filters as I write the date/mileage on the end cap when I change the oil.

-Joel.

mortymower

The 928 one does not have the drainback because in the 928 it mounts where the oil will not drain out when no pressure (as i previously stated). Not good for 951's

Luis de Prat

Some people rave about the Canton billet aluminum unit with replaceable filter element, but I still think it has this same problem, since the anti-drainback valve is a rubber washer. Bought one back in 2001 or so and decided not to install it because of this.

marcoturbo

That's odd.

Official Porsche dealers here in France only sell the "tall" 928 oil filter (OC 75). The "small" oil filter (OC 142) is no longer available. Don't the new 928 oil filters have the anti-drainback valve ?

Charlie944

The MAHLE OC-75 is the high capacity version of the MAHLE OC-142 filter used for the 944's. The OC-75 is actually a 911 filter and has the anti-drain back valve. I run these mainly. Amsoil's Ea-36 filters have great filtration but no drain back valve. I have ran the K&N 4001 filters too and like the 1" nut on top for easy on and easy off but hardly can you find a place that carries them in stock. They do have the anti-drain back valve. Last time I bought some was with another order from Summit Racing. The 928 filters do not have the anti-drain back valve. That was one thing I looked for when my friend bought his Euro 928S.

Luis de Prat

Hey Marco, are the French OPC filters "Made in USA" like the ones Porsche sells here in Spain?

Charlie, will the OC-75 fit the 951? There's less clearance there than in the NA cars.

EdC

What year 911 uses the OC-75?

marcoturbo

I can't remind what it's written on my oil filter. I don't have a spare one left, so I can't check.

I currently have the OC 75. It does fit the 951 and it's easier to install/remove.

I have thought the OC75 come from the 928s, not the 911s... Good news if there's an anti-drainback valve

EDIT: I've ckecked, the 928 filter (according to french parts sellers) is a OC 46

LFA951

There was an STP and a Purolator, both without the valve in stock, so I took the Purolator and on the next oil change in 2 months, I'll order some Mahn filters to have handy.

George D

I just looked at my Mahle filters. They are OC 142 Black and made in Austria. Anyone else have these? Just hoping that they are the real deal.