Best oil for a 110k S2?
- Thread starter Joss Walker
- Start date
Just what I was thinking. I buy good quality 10W40 semi for a smidge under £2 per litre.
It strikes me that oils seem to come in two price ranges; reasonable (for the semi-synths) and oh-my-word-that's-pricey (for the esoteric fully-synths). I'm sure the esoteric fully-synths are worth the money in modern engines if you are leaving it 50,000 miles between changes, but in an agricultural old Porsche engine then I am more than happy to use the cheaper stuff and change it more frequently.
As they say, you pays your money and takes your choice ...
Oli.
Sandspider
New member
I did a second fully synth oil change, with 10w50, as I thought the 5w40 may have been too thin. It still consumed / lost more oil than previously, and continued to do so when I went back to 10w40 semi synth.
I did trace a small oil leak to the rocker cover gasket. This has now been replaced, and I hope that (and continued use of semi synth oil) will fix the problem. I will stick to semi synth oil, as I feel it's more appropriate to the older 944 engine, and it's so much cheaper that I can get good quality oil and replace it much more often.
Giles
Copperman05
New member
An old post and discussion that still goes on regarding ZZDP levels in modern oils. ZZDP is an old yet cost effective anti-wear additive, used for many years as a cheap boundary lubricant.
Times have moved on, and although ZZDP is good there are now better alternatives, Molybdenum and Boron Nitirate being two. If your concernd about ZZDP levels in your oil just make sure you buy one that contains it!
Edd
Copperman05
New member
Premium oil demands a premium price tag, like most other things. Although TBO when compared to how much you might spend on fuel in a year, £2000+ (10,000 miles), £74 is just pocket money for piece of mind.
Edd
Edd,
I'm not well versed enough on the additional properties of expensive oil vs. cheap oil, but I do know that a LOT of tribology development has centred around oil life expectancy and how long you can maintain the lubrication properties and thus lengthen service intervals. On this basis I'd wager that the extra expense of such oils is wasted if you are changing it every 5,000 miles - as I do.
Maybe £74 is a drop in the annual ocean of Porsche running expenses, but if it's a drop I don't need to spend then it's staying in my pocket.
Oli.
I'm not well versed enough on the additional properties of expensive oil vs. cheap oil, but I do know that a LOT of tribology development has centred around oil life expectancy and how long you can maintain the lubrication properties and thus lengthen service intervals. On this basis I'd wager that the extra expense of such oils is wasted if you are changing it every 5,000 miles - as I do.
Maybe £74 is a drop in the annual ocean of Porsche running expenses, but if it's a drop I don't need to spend then it's staying in my pocket.
Oli.
Copperman05
New member
I know I should really get a life (and I hope to one day) but oil and how it functions in our engines fascinates me.
I do see your point, although there are other added benefits to using synthetic oils beyond the extended service intervals. Better fuel MPG, increased winter protection, superb high heat stability and improved anti wear properties. Although some service intervals are now 15,000+ I think OCI's are optimum at 7,500-10,000 miles with synthetic oil due to metal contaminants and possible fuel dilution of the oil.
In my mind I prefer to pay the added premium for synth oil in return for the extra insurance it brings.
Edd
I do see your point, although there are other added benefits to using synthetic oils beyond the extended service intervals. Better fuel MPG, increased winter protection, superb high heat stability and improved anti wear properties. Although some service intervals are now 15,000+ I think OCI's are optimum at 7,500-10,000 miles with synthetic oil due to metal contaminants and possible fuel dilution of the oil.
In my mind I prefer to pay the added premium for synth oil in return for the extra insurance it brings.
Edd
Edd,
As a founder member of the no-life club (I am being referred to as 'boring' on the Sat Nav thread on here at the mo! [&:] ) I share your interest! And the fact that I don't know what I am talking about is underlined by my failing an engineering degree many years ago ...
I am sure there are other advantages in using synth oils, but can't believe that they are worth the money. The advantages, that is. Fuel economy is a function of viscosity and lubrication, which is denoted by the oil grade. Winter protection may be better, but winters make me worry about car bodywork, not engines. High heat stability - yes, but not necessary on a road car. Anti wear - again, this is an issue if you are stretching the service intervals, but I don't do this. A cheaper oil changed often is (almost always) better than an expensive oil changed infrequently - an an engineering principle. (Heck - look at the spec for the cars, as posted above - that recommends mineral oils for 944's changed at 6,000 miles!)
As I said, I am sure you are getting benefits for your money with the fully-synth, but they aren't useful benefits which are useful to me.
Incidentally, service intervals are getting longer and longer, and I think that Dodge has a model in the US with a 100,000-mile service intervals. (Yes, 100,000 miles.) Longer service intervals are seen as a sales point on new cars, and manufacturers want to be able to offer this hence oils have been developed with this in mind. (Would you really want to leave the oil in your car for this long? No ... but most car buyers aren't of that mindset!)
Oli.
As a founder member of the no-life club (I am being referred to as 'boring' on the Sat Nav thread on here at the mo! [&:] ) I share your interest! And the fact that I don't know what I am talking about is underlined by my failing an engineering degree many years ago ...
I am sure there are other advantages in using synth oils, but can't believe that they are worth the money. The advantages, that is. Fuel economy is a function of viscosity and lubrication, which is denoted by the oil grade. Winter protection may be better, but winters make me worry about car bodywork, not engines. High heat stability - yes, but not necessary on a road car. Anti wear - again, this is an issue if you are stretching the service intervals, but I don't do this. A cheaper oil changed often is (almost always) better than an expensive oil changed infrequently - an an engineering principle. (Heck - look at the spec for the cars, as posted above - that recommends mineral oils for 944's changed at 6,000 miles!)
As I said, I am sure you are getting benefits for your money with the fully-synth, but they aren't useful benefits which are useful to me.
Incidentally, service intervals are getting longer and longer, and I think that Dodge has a model in the US with a 100,000-mile service intervals. (Yes, 100,000 miles.) Longer service intervals are seen as a sales point on new cars, and manufacturers want to be able to offer this hence oils have been developed with this in mind. (Would you really want to leave the oil in your car for this long? No ... but most car buyers aren't of that mindset!)
Oli.
Copperman05
New member
Better fuel economy due to viscosity and lubricity, the first as you state governed by oil grade the second by the base stock used. Synth oil generally has a higher lubricity than semi or dino oils, this creates less friction, less drag and better MPG and even a tiny bit more HP.
Winter protection, about 90% of all engine wear occurs during start-up in winter, ester oils are expensive because they contain synthetically modified saturated fats that are almost near perfect in being the same size and are highly polar. This polarity means they are electrostatically attracted to the metal surfaces in an engine, meaning surfaces are protected even before oil has started circulating the engine. This is very much the same tech as used by Castrol magnatec, except magnatec was a marketing gimmick as it only used about 1-2% ester, most ester oils are 25-50% ester + PAO base oils.
High heat stability on a road car, perhaps not something you'll need going to Sainsburys, but surely of benefit stuck in a summer traffic jam, or holiday to south of France driving in the alps, or trip to the Nurburgring, in an occasional track car the benefits are further apparent.
100,000 oil change interval! Thats just mad. Even if the oil did manage to maintain its lubrication (which I doubt it would) just imagine how much worn metal, crap that gets through the air filter (because some crap does get through), carbon build up, there would be. Any savings in servicing costs would be countered by replacement of worn parts. Which brings me to my original point, if you have no intention of keeping the car beyond the 100,000 mark, it probably doesnt matter. Maybe thats the point....
Edd
We looked at trying a machine which basically cleaned all the crap out of the oil and the same oil went back in the sump. This was done through centrifuge and also a very fine filter. This was for railway locomotives as they take between 400 to 800 litres of oil per loco. The oil is very rarely changed on a loco as it is topped up quite often. The filters should however be changed more often as this is what stops the crap running round the engine. It is also dirt in the oil that can cause premature wear in any engine. We also use straight 30 oils in all our engines. The engines were designed for this so this is what is best to use. A modern multigrade would just be a waste of money. The engines typically do 10,000 hours before rebuild is required and have some interesting thermal cycling. Either idle or full power with nothing really in between. Think of your lovely 944 flat out at the redline continually for 3 to 4 hours.
As stated, the original spec of oil for these cars was quite a lowly spec when they were used, there was no fancy oils really 25 to 30 years ago. If the car is being raced, fair enough but if it is used as the maker intended, what is the point in putting 50 or 60 quids worth of oil in a car that is changed every 6000 miles. I use semi synthetic with the top API and SAE rating which is miles better than anything when the cars were used. I also change the oil on cars at 4,000 and use genuine filters with a non return valve, many of the cheap filters don't have them. Genuine ones are £7 a go so not expensive.
Alasdair
As stated, the original spec of oil for these cars was quite a lowly spec when they were used, there was no fancy oils really 25 to 30 years ago. If the car is being raced, fair enough but if it is used as the maker intended, what is the point in putting 50 or 60 quids worth of oil in a car that is changed every 6000 miles. I use semi synthetic with the top API and SAE rating which is miles better than anything when the cars were used. I also change the oil on cars at 4,000 and use genuine filters with a non return valve, many of the cheap filters don't have them. Genuine ones are £7 a go so not expensive.
Alasdair
[FONT=arial"]No disrespect intended but to suggest that the basis of that thread and some of the main contributors are living in the past is somewhat hasty.
![[FONT=verdana,geneva"]](/forum/styles/default/pcgb/space.gif ". [FONT=verdana,geneva\"]")
[FONT=arial"]Moly and Boron are also products that have been around since Adam so they're certainly nothing new. [FONT=arial"]People like Steve Weiner and Charles Navarro have built literally hundreds if not thousands of Porsche motors so I am very happy to listen to them. [FONT=arial"]Let alone accounts from my own mechanic who has seen premature engine wear with cars that have used so called 'Approved oils'. Most of these [FONT=arial"]being lower viscosity synthetics with reduced ZDDP in the package. We have seen these oils come out of a hot car that appear to have consistency of [FONT=arial"]hot water! Clearly climate and usage have a large bearing on what Visc to use, but we have had very good success with mineral oils of between 20w/50 and 25w/60.[FONT=arial"] ORIGINAL: 333pg333
[FONT=arial"]No disrespect intended but to suggest that the basis of that thread and some of the main contributors are living in the past is somewhat hasty.
Millers claim their CFS and classic range contain the optimum amount of ZDDP, that's one of the reasons I decided to use their oil. There had been a minor but persistant leak around the front of the cam box on my car for around 3 years whilst using 5w40 oil, since I changed to 10w50 the leak has stopped.
Copperman05
New member
ORIGINAL: 333pg333
[FONT=arial"]No disrespect intended but to suggest that the basis of that thread and some of the main contributors are living in the past is somewhat hasty.
I'm sure you do Patrick, there is nothing wrong with using 20w50 in the right application and seeing as you race your cars alot it would appear to be a good choice in your climate.
My point is that in a engine that is in good mechanical condition there is no reason why one cant use the thinner oils and the fact that these (5w40) were used as factory fill from 1992 confirms that point (contrary to popular belief it seems).
Edd
Copperman05
New member
A bit like blaming water for being too thin when your sunroof leaks, fix it and the leak stops whether its thick or thin oil. The leak is still there the 10w50 just masks it better.
Many modern oils still contain sufficient amounts of zinc (ZDDP), synthetic and semi/mineral, about 1200ppm is apparently a sufficient quantity. Finding which though can prove more problematic as this is not widely published. There are analysis avaialble on the web but most people I would assume would not bother to find it.
I should get the oil company we use to make up some Porsche specific oil, I could make a killing! At the end of the day, there are 2 companies in the UK that make additive packages and 3 that supply the base oils. As long as the spec is the same and the additive package is correct, you are paying for a name. Why do you think there is such large profits with oil companies?
Alasdair
Alasdair
Copperman05
New member
I mean surely its better to fix the leak by fitting new seals, etc than by masking it using a thicker oil. It may not leak whilst you are using a thicker oil but it does mean that the underlying problem is still there. My point is its not the oil but the damaged/worm seal that is the issue here.
Edd
Copperman05
New member
I'm sure its a very good oil, it seems to be good at stopping leaks at least.[
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Edd
]Edd
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