katmando31

My owners manual doesnt specify when to change the oil. Is every 3000 miles? Or as some have suggested 15000 miles?

Thanks,
Katmando

ErnestSw

It depends on which oil you're using and how you're driving. A synthetic that you get hot every day will last 15K. A non synthetic that you only use occasionally and don't use very long at a time could need changing every 3K.

Steve J.

I think my owners manual says every 15K but I change every 3-5K and the oil still looks relatively clean. I rarely have to add any oil between changes, though I heard it is normal for the 928 to use some oil - as much as a quart every 1500 miles.

katmando31

Thanks Steve & ErnestSw

I am going to change mine every 3000 - 5000.

ErnestSw I drive my shark twice a week, and my commute is 30 miles each way. Would you consider that a long way?

Thanks,
Kat

Lizard928

I have 267,000 kmph on the odo (KM) and I have just had the timing belt done around 5000 km ago, and the front oil seal was also done, in those 5000 km, which have not been low rpm or easy miles, the car has no lost 1 little bit of oil. I am going to be doing the oil change fairly soon though, but seeing as I put on about 1000km a week on the car, it is not practical for me to change the oil every 3000km, and the oil is still a great color

I am going to be running castrol syntec 5w50 in the car

Doug Hillary

Hi,
katmando31 - Porsche have advocated long drain periods for the 928's engine oil from the very beginning

Shortly, the fourth and final Used Oil Analysis of the oil from my car will be able to be published here. It will have done almost 12 months and about 8500 miles service - it will most likely still be suitable for further use. But it will be changed then in any case

Porsche's oil change recommendations are 12000 miles or one year or thereabouts for your year 928

A good API SL/CH4 & ACEA A3,B3 ( B5 ) oil of the correct viscosity and an OEM oil filter will do the job well. Unless you are racing the car of course!

The earlier Oil Condition Reports Nos 1,2,3 are on here but you will need to search

Regards

WallyP

I agree with Porsche - for MOST 928s, an annual oil change is probably fine. I prefer to change mine in early spring - gets rid of any winter condensate.

Of course, you do realize that for many owners this is a religious decision, not an engineering one...

Lizard928

just like cleaning the pipes out right wally

ErnestSw

30 miles each way twice a week should cycle the oil temperature enough to keep it in good shape. You can go 12K to 15K with a good synthetic. As Wally says, for most people it's a religious decision and has nothing to do with the facts.

Nicole

Wally could not have said it any better. And the preacher of the religion are oil companies and oil service stations like Jiffy Lube...

The 928s oil reservoir is pretty big compared to other engines of that time. That's another factor that helps keep the oil clean for a long time. If you have twice the oil floating around, the same amount of "dirt" is onlyl going to make it half as dirty.

Doug's research shows very clearly that the Porsche factory is not out to sell replacement engines. Thanks, Doug!!!

Gretch

I have standardized on the "Hillary papers" for all my machines, not just the fleet, but the tractors as well.

When it comes to my soul I do "religion" because I don't have any "facts", everything else gets science applied.

Jim bailey - 928 International

Thanks to Doug Hillary we now have proof that there is no need to change oil every 3,000 or 5,000 miles . Porsche engineers stated 15,000 miles or once per year . Even if you really love your 928 and want to be especially nice to it changing oil every 7,500 miles is still twice as often as it probably needs it . Changing oil every 3,000 miles would be much like changing the timing belt every 12,000 miles , if you do one you "should" be doing the other . Hey wait I sell oil filters $5 each make about $ 1 each ............maybe everyone SHOULD change oil every 500 miles Yea that's it change oil every 500 miles ...Which is nearly as absurd as the advertising by all the " quick lube " oil change franchises . Again thanks to Doug Hillary for testing the oil in his S-4 . It is refreshing to see facts supporting an opinion .

Steve J.

If a timing belt change only took 30 minutes and cost $25 I might change more frequently than recommended. Looks like I can relax on oil change intervals. Old habits die hard. All my cars since 1972 have gone 200K+. My Toyota truck just hit 300K and doesn't use any oil. I always attributed the longevity to frequent oil changes. Seemed like cheap insurance and better to err on the side of safety. At least I didn't harm the engine by changing oil too frequently. But Doug's numbers don't lie. This is good information! Thanks!