Porsche Enthusiasts Club Forum

I'm confused by this thread ,as everytime somebody put forward an oil that theyve used in their car then another would post the downsides or even that your engine was about to be destroyed by that type oil if you use it again, you sound like statler and waldorf from the muppets

I know alot of this is typical forum nonsense and even the porsche specailist backtracked a little who started the whole thread

so the big question

WHAT BLOODY OIL CAN I PUT IN MY CAR? (1991 944s2)

I'd like to goto halfrauds or eurocarparts buy some oil and chuck it in I know about the zddp stuff and alot of the oil
people recomended are listed as motorsport oils ? I was thinking of just putting in mobil 10/40

an interesting read, good to know and a relief as ive always used mobil super2000 10w40 semi synth in my 924. although my oil change intervals are between 4 to 5k miles or 3 to 4 months as i do about 20k miles a year

If you read the manual then the recommended oils are in the 10W/40 -10W/50 ranges & for road use any good Semi Synth will meet the specs for an S2. In my older 2.5 I ran Valvoline VR1 Turbo which is a good mineral. Better is to change it often, if it is a low miles car then a change every 3K is easy enough. When mine was a daily driver I did 6K oil changes.

Generally avoid any of the current oils especially starting with 0W or 5W, these are specced to meet emission & fuel consumption compliance rather than good engine protection.
If anyone lives in Kent & wants some I have around 20L maybe more of VR1 here & as my 944 has gone & Paul is selling his then I have no need for it any more.

well a low miles car from 1991 is 104 k miles

yes it is an intresting read ,quite a few contradictions also

I am leaning towards either mobil 10/40 as I can get 10 litres and use it in my other cars or maybe a miller oil

Ive got the filter and the sump washer ,bucket ready and waiting just need to buy some oil!!!!

My S2 has just gone through 100,000 miles

I recently covered 1350 miles in 5 days across Europe

Some very spirited and continuous driving

I use Mobil 1 10/60 Motorsport Fully Synth

Oil pressure perfect throughout - hot or cold !

Worked for me - Nuff said

I also use Mobil 1 10W60 in my car with no issues. I may change to Millers 10W50 for the next service however. I probably would not go any thinner on a Turbo though.

My S2 ran fine on 10W40 as I do suspect many others as well as the NA cars.

For other cars I have had great results from Valvoline VR1. Certainly in my Stag VR1 20W50 is about the only semi cheap classic oil which actually maintains good hot oil pressure (Unipart's offerings were useless and Halfords classic stuff did not seem much better (their normal oils are fine for my moderns though). It is small wonder that some engine builders will void the warranty of an engine if VR1 is not used.

I was running 10/60 fully synthetic and have just changed to 10/50 fully synthetic at recent change. Both oils perform well but engine is a tad quieter on the 10/60 as it doesn't thin just as much at full temp. I have a tappet that gets slightly noticeable at full temp and is slightly less noticeable on the 10/60! I only changed cos the 10/60 can be a bit thick on icy cold mornings. May well go back to 10/60 at next change. Would not not consider anything thinner on an engine which although has various new parts inside still has some 25 year old components providing sterling service! Less leaks too on a thicker oil although all my seals are quite new.

Stuart

Off topic slightly but I had 4 or 5 Stags years ago, had to put a higher pressure oil pump in one to stop the oil light coming on when the oil got hot. Didn't keep that one long .

So can anyone tell me why a 0w40 or 5w40 is any worse for an engine than a 10w40? As far as I know once the engine is warm they are all the same i.e. 40 weight oils. The only difference I can see is their viscosity at cold and my understanding is that the lowest number e.g. 0 would give the most engine protection at a cold start.

I'm running millers trident 5w40 which claims to be high ZDDP in both my cars. At full temp I'm getting 2 bar in the 928 and 2.5 bar in the 944.

well I bought 10 litres of mobil 10/40 semi 22quid for 5 litres so good value

did a bit of work on my other classic today (mr2mk1) and changed the oil on that it only holds 2.8 litres but took it for a little run
and it ran loverly and raw as allways got enough left for the 944 now probably do it tomorrow

Without going miles off topic I think I know why one of your engines went bang (as you probably do now).

Bar one supplier (T.D Fitchett who sell factory reconditioned pumps) all of the pumps sold via the various suppliers (Rimmers, Robsport, maybe even Wards) are repros which are not quite in the same league of quality as stock items (some have noted burrs and minor inside!), but all of them come equipped for a Spring on a Saab 99 (which is what the pump is). What you are meant to do is to transfer the OPRV spring assembly from your old pump into the new one. Many do not.

The result? Too high oil pressure for the Stag (around almost 100 PSI running, and around 50 idling). People who have looked into this with more depth have said that this pressure is too high to the extent that the chain tensioners no longer get an adequate supply of oil (the oil is only meant to almost dribble out of the tensioners) leading to premature wear with disastrous results (tensioners basically failing).

When I was talking about my oil pressure I was referring to my hot oil pressure being around 50PSI when hot (now around 55), but more importantly the hot idle. Previously it will get to around 1/2 bar on hot days (I was beginning to wonder whether my engine was toast!). Other owners on cheaper 20W50s or 15W40 oils noticed a similar thing. Now it is around 1-1.5bar hot idle, pretty much bang on the book values , with it not dropping off in pressure as the oil breaks down before the next service (which is what seemed to happening with the Unipart stuff (the pressure was fine initially after the oil change, but a few months after....).

None of my Stag's engines ever went bang or over heated while I owned them. It's over 20 years since I last had one and back then I knew a sound one when I drove it. The car with the low oil pressure was bought and then sold as seen

did the 944 s2 oil and filter change put in the mobil 10/40 then took it for a run ,at temp it did have a little bit more oil pressure than normal showing 2.75 instead of 2.5 but that might just be new oil but when warm the engine seemed to run smoother ,got a feeling the mechanic that did my engine put 5w30 in a few months ago as he uses it in his garage alot he did a great job but has never worked on one of these cars before

Oil = religion etc...

However I would add that it's not just about flow and it's not just about pressure i.m.h.o.
Temps and film strength is also paramount in our motors. I am really a bit suspicious about oils that claim to have such a wide operating range like 10w/60. Usually things that appear too good to be true are just that. Film strength is also very important when the car is hot ie Summer traffic or on the racetrack. When I've seen some light grade synth oils when hot they appear to have less viscosity than vapor. Not my idea of good protection. Having a decent grade oil with sufficient ZDDP is really important under stressed conditions. We use a VR 25w/60 and put in some STP additive for our trackcar.

Alot of garages may use 5W30 since it has become a common grade amongst many cars, including VWs Fords and BMWs