What's your favourite oil?

[aprotogerellis]

Hi there,

Its about time for my first oil change on my '88 944 lux and am struggling to find a consistent opinion on what oil to use. Up to now I have heard practically every variation, with some themes comming through:
- As the previous owner hadn't used synthetic, neither should I
- Porsche recomend 10W40 Mobil 1
- Halfords say mineral

Ideally what I'd like is to reach a conclusion on exactly which oil I should buy.. so I'm throwing the question to the forum:
What is your favourite oil?
(mine, being Greek is obviously extra virgin olive oil

 

[Peter Empson]

Hi, I currently using some fancy Silkolene stuff, but previously I used Magnatec in my Lux and it certainly seemed to do a good job, plus its reasably priced and easily available, so I think that would be my recommendation.
Best regards,
Peter

 

[Diver944]

I've used Magnatec 10W40 in my S2 for the past 80k miles, changing it every 6k

 

[sawood12]

I have also used Magnatec on all my previous cars but use Silkolene Fully Synthetic on my 944. I don't think there is any restriction on using fully synthetic after the car has run on mineral or semi synthetic previously - so it's your decision if you think you are getting any percieved benefit from the more expensive fully synthetic oil.

 

[333pg333]

You will get a lot of push for low viscosity synthetics a la Mobil 1. It may be different in the UK to Australia due to average temp. variations but my mechanic who has been working on Porsches for over 30 years, has found that a huge majority of cars that have had engine failures have all been running on M1 and the like, whereas cars that have done over 300,000 kms on a higher viscosity oil have shown amazing signs of very little or even no wear! Our cars were not designed for this type of oil (M1) and most of us have been sucked in by the propaganda of a huge marketing budget. Porsche themselves succumbed to it as Mobil threw oil at them for free. I use a Castrol 25/50 and have no problems whatsoever. My pressure starts at 4.5-5 and never gets lower than 2.5 on the gauge even under race conditions. The lo-visc synth's will get too thin under high temps and not offer natural suspension characteristics between major components, especially bottom end. If you scour many of the forums re our cars and read about the guy's who've had engine failures they are almost all using M1. They also never seem to blame the oil, instead invent reasons why it must have been a component failure. There is always one common denominator. The oil.
Now I'm going to put on my race suit as it will probably get a little warm soon enough. lol.

 

[TTM]

I have been using Castrol RS 10W60 and may consider Valvoline VR1 20W50 next time I can't find any Castrol RS.
Anything below 10W40 remains too thin for these old engines, no matter what supposed oil experts may say.

 

[stevep2000]

I've been using the Mobil 1 15w50 - can see the 0w40 being a problem, but thought this stuff would be ok?

 

[stevep2000]

I'm probably talking [:-] on the 0w40 - see here for a more informed view -

http://www.porscheclubgbforum.com/tm.asp?m=75433

Also, didn't think you could get a 10w40 Mobil 1? (0w40 or 15w50?)

 

[944Turbo]

I used mobil 1 15/50 and then used Silkolene Pro R over 90,000 miles taking the total to c180,000 (previous owner also used mobil 1) Head came off for head gasket and the bores were unmarked. Very hard miles, regular bouncing the limiter in lower gears, extra boost etc.
Even on the hottest days at tickover pressure never drops below 3 bar.

10 years ago I ran tuned minis and used to get through engines & drop gears every six months or so. Swapped to mobil 1 and 35,000 miles (with bigger displacement/power/torque) before an issue.

Tony

 

[Guest]

Well here goes!
If money is no object Amsoil 20/50 Seems to be the ultimate run my 7.1 V12 on this
Sensible Option - Mobil 1 15/50 Currently in my Turbo
Cheaper Option Valvoline Racing 20/50 just change it every 6000 mile swithout fail otherwise youwill start getting carbon build up

 

[edh]

I use Millers CFS 10w60 - keeps oil pressures nice & high when things get hot on the track

For road use, a decent mineral 10w40 & regular changes should be just fine.

 

[zcacogp]

I use 10W40 semi-synth, purchased from a Vauxhall dealer ... yes, Vauxhall - I am reliably assured that Vauxhall specify some of the highest requirements for their oil and it is therefore one of the best out there.

I also have a mate in the trade who can get it cheap from there (as well as from other places), and he recommends it as good stuff too.

A personal opinion is that the quality of the oil is possibly less important than the frequency of changes. Fancy-schmancy Mobil 1 changed every 30,000 miles? Or something more mundane, swapped every 5,000 miles? I know which I would choose. I try to do mine every 6,000, but it's usually picked to be the time when I have a free weekend and I know it's a bit over 5,000 miles since it was last done ...


Oli.

 

[Hilux]

Our cars were not designed for this type of oil (M1) and most of us have been sucked in

I`m inclined to agree.

I use 10W40 semi-synth, purchased from a Vauxhall dealer ... yes, Vauxhall - I am reliably assured that Vauxhall specify some of the highest requirements for their oil and it is therefore one of the best out there.

True..and cheaper to buy.

Also Audi/BMW spec oils too.

Remember that high performance Audis/BMW`s and Vx`s et al are designed to go up to and beyond 12K between changes so I cannot see why a v v expensive specialist oil offers benefits unless you do lots of track work where you do not want oil break down (unlikely with modern synths)

Changes after two or three track days and 3000 miles are what I do.

i`m sure someone here stated that they use Magnatec regularly without any issues???

 

[Guest]

Hi There,

After pndering the same question recently I decided like some others above to put Magnatec 10w40 in mine at the weekend when I did the change.

 

[Guest]

Ah, somebody is getting misinformed!!
If you use Mineral Oil and change your oil too regularly you cause problems. When oil is new it has detergent qualities from its formula that are quite acidic. If you keep changing your oil before the carbonisation neutralises the acidicy you will end up doing damage because your engine will rapidly become more and more acidic. With Aluminium blocks this is dangerous as it can lead to your block becoming porous as well as affecting the white metal on your big end, main, small end and cam shells. It can also affect your gaskets and cause leakage.
From my last dealings with OPC Service they actually recommended and used Mobil 1 15/50 but that was a few years ago. So it was far from our cars not being designed to run on this, it was actually authorised by the factory.
Under no circumstances use the 0/40 this is definately not for our cars.
The Castrol RS is also a good all round oil too.
As for cost of oil, yes it is stupidly high in UK. When I go over to France (quarterly booze cruise!)
I always come back with 12 litres of Mobil 1 15/50 from Aachen supermarkets it is half the price!
Just my $0.02 worth!!

 

[John Sims]

Mobil 1 15w/50 for me.

I used to use Castrol RS but was told that the viscosity enhancers necessary to achieve the 60 rating get chopped up within the first 1000 miles so you are only buying 50 weight after all.

 

[Fen]

I use Texaco Havoline 5w40 synthetic in all my cars. It's BMW recommended whcih is why it goes in there and while it's slightly thinner than most people use in their 944s it did actually stay in the sump - bear in mind my engine was a fresh build.

Of course my engine went bang so maybe my oil recommendation would be the best, but on talking to lots of people I am now convinced it was a fuelling issue. Not an issue with the map as it affected only one cylinder, but more likely a starvation problem that caused #4 (at the far end of the fuel rail) to run lean momentarily on peak demand, either siezing the piston in the bore enough that the rod pulled out of the skirt or creating a momentary detonation event that broke the piston skirt.

 

[944Turbo]

dodgy injector?
Tony

See also http://www.emeraldm3d.com/em_walkers.html about half way down,
Tony

 

[Fen]

Possibly, though I have ruled that out on the basis that it would likely be less intermittent than this seemed to be. I had one misfire in third at peak torque and WOT followed by a smooth run through the rev range at part throttle and then the failure next time I tried WOT.

I think a dodgy injector would have manifested itself at other times than WOT & peak torque, especially as the car had just been run with the det cans on for a couple of hours and a weak injector should have shown up as pinking.

edited as I clicked send too early

 

[Indi9xx]

Mobil 1 - Fantastic oil, but expensive.
Fuchs - in the same group of companies as Mobil and Silkolene, seems very good
Silkolene - as with Fuchs
Shell Helix range - a good oil again, very much as good as mobil
Castrol - used to be good, but we find that engines run on magnatec seem to have a lot of sludge and varnish internally
Valvolene - Pants
Elf - Not a bad oil, almost as good as Mobil
Q8 - So so, nothing bad to report like with castrol... But nothing outstanding either.

All of this is from experience from 944's and also in some ways more importantly with air cooled porsche models, which can tend to be harder on oils due to the oil being important for cooling.... you can tell how good an oil deals with heat and oil pressure based on how good it is within an air cooled engine, as they exagerate the thinning of the oil and problems of heat transfer to and from the oil.