carguyhere2

Mobil one site, says 0W-40, and I've read somewhere that minimum should be 15, and anything less could cause wear issues.

I know what porsche wanted 24 years ago, but oils have changed.

So with today's oil, what is the best for a 1988 928??

http://www.landsharkoz.com/tech/bb/bbipr.htm

"Here are some interesting observations we have seen in the last 12 months with 928 and 944 models, particularly the Twin Cam Engines, showing signs of unusual engine wear.


In the last 3-4 years we have been reading reports in the American, but mainly the English Porsche magazines (Independent), about excessive wear of the camshaft lobes and the sprockets which are part of the camshafts where the single row cam chain runs. If the sprockets wear out then its new camshafts etc and if the lobes are worn too then a complete set of lifters is required as well. Plus they mention the hydraulic tensioner slippers and at times excessive wear of the V8 engines thrust bearings.


We too have seen a small amount of unusual wear on the top ends, but in all cases the engine oil that was drained was very thin and when asked, the owners confirmed in each case that the engine oil used was a viscosity of less than 10w-50.


By comparison we have seen and inspected hundreds of 944 single and twin cam, 928 single and quad cam engines top ends, over many years and in cases where after 15-20 years of heavy high temp city work the engines have been removed and dismantled to replace all seals and gaskets, they have been running on a 15w-50, 20w-50 or 25w-50 oils, there is no wear at all, and at worst a couple of worn valve guides at 200,000 km+."

PHIL928

20W50 no less! *HIGH ZDDP*

ammonman

As i understand it, the wear issues have less to do with viscosity (as long as you are running a viscosity appropriate for your climate) and more to do with many oils being re-formulated in the last several years with less zinc and phosphorous so as to be more catalytic converter friendly. One of the members here is a retired petroleum or lube engineer (can't remember his name just yet. too early in the am.) has written a nice treatise on oils and 928's. Basically as long as you get the right weight for your climate AND an oil that has over 1100ppm zinc and 1200ppm phosphorous iirc your 928 will be happy. Two oils that meet this requirement from Mobil are the 15W-50 and the 5W-40 Turbo Diesel Truck oil (which is rated for gasoline engines as well as diesels.)

Hope this helps.

Mike

SeanR

15w-50 or 20w-50 is my preferred oil viscosity. I will not use anything less in mine or customers cars.

IcemanG17

15-50 or 20-50....NOTHING LIGHTER (unless you live somewhere VERY cold)...also you need a high "Zinc" (ZDDP) formula....

Of course if you drive only on the street and don't spend much time at high rpm, especially in the corners...then almost anything is fine....

namasgt

I would only use 15 W50 or 20 W50. If I recall correctly someone here was using 10 W30 or 40 on their 16 valve and the engine started making metal.

It is misleading sometimes when you go on oil websites such as Amsoil and they list 0 W40 for all temps for a 928. The 0W40 weight is used on the newer Porsches not the older ones.

Here is what Amsoil shows which is wrong...

1988 PORSCHE 928 5.0L 8-cyl Engine Code [B] 81J
LUBRICANTS & FLUIDS:
Engine Oil
Grade 1......SEO[1]

Performance AMSOIL European Car Formula 100% Synthetic 5W-40 Motor Oil (AFLQT)
Above -13 F......5W-40, 5W-50
All TEMPS......0W-40

hacker-pschorr

It does depend on when you are driving the car, is this spring / summer / fall, or winter in Minnesota (the car in your avatar is from the Minneapolis area)?

dr bob

So much depends on coolant temperature, which indirectly affects oil temperature. Unless you live in a climate where you have multiple cold-engine starts from -10ºF or colder, and never run the oil temperature up, follow the guidance here. The Mobil-1 15W-50 Extended Life oil has more zinc than their conventional oils. I know there are lots of folks who are fans of the Brad Penn (used to be Kendall), and one or maybe two who believe that the only oil to use is Amsoil. Performance engine builder Greg Brown recommends Torco last I heard.

----

Oil viscosity recommendations from Porsche for your particular car are enshrined in a double-top-secret book called the Owners Manual. These books are often hidden in an innocuous-looking folder in that storage box over the passenger's knees. The longer key in your set is needed to access the insides of that compartment. Be sure to lock the compartment when you are done. so nobody else can gain access to this otherwise-secret information.

Maleficio

pcar928fan

20/50 FOR SURE! Year round!

mark kibort

there are many stories of lost engines using other oils than 20-50. i would use NO other oil viscosity, but the 15-50 .

Dan87951

I run Rotella 5-40 or 0-40 Mobil with no issues. I have put 50k on my cassirot 928 with no issues with this oil.

Leon Speed

You guys are lucky. There is no 15W-50 or 20W-50 available in Europe.

jon928se

Heed the words of Dr Bob

I am sure you can find 20W50 in Europe if you try.Try Fuchs for a start, but all the major oil manufacturers still make 20W50 along with many minor manufacturers.

GlenL

Please link to three.

I will use 5w40 in the Winter. Mark is not familiar with Winter.