Which Engine Oil?

[Ashley James]

Interestingly they don’t say whether or not their classic oil is mineral or synthetic, but they do offer a 10w60 alternative, which almost certainly is.

[mycar]

This 20W-50 Porsche Classic Motor Oil is specially adapted to the early air-cooled models for all 356, 914 and 911 models with a displacement of up to 2.7 liters. This mineral oil is available in 1 or 5-liter cans.

For all 356, 914 and 911 models up to the 2.7-liter G-Model, Porsche recommends the multi-grade version with a viscosity of 20W-50. Back in the 1950s, 1960s and 1970s, engines were built with much more generous tolerances than today, which is why the viscosity of an oil must be low enough for it to penetrate into all areas of the engine as quickly and uniformly as possible during cold starts. At the same time, however, its viscosity must not be so low that a stable lubricating film is no longer present when the engine heats up. The developers went to particular lengths to achieve excellent cold start properties for the oil, so that the engine can be lubricated as quickly as possible when started. The CCS test was especially important in this respect, since it simulates the behavior of the oil in the crankshaft bearing during cold starts and at low temperatures.

The Porsche Classic 20W-50 is a mineral oil known as a hydrocracked base oil with mildly alloyed additives. Hydrocracked base oils are characterized by a very low level of contaminants, a very low sulphur content and very good oxidation and aging stability, which prevents deposits, for example. At the same time, the Porsche Classic Motor Oil 20W-50 has an extremely high HTHS viscosity (High Temperature, High Shear), which describes the quality of the engine oil at high temperatures (150 °C) in the lubricating gap and with high shear rate (engine speeds). Finally, the excellent shear stability ensures that the optimum lubricating properties are reliably retained at high engine temperatures, even after long periods of operation and under high loads.

In a nutshell: low levels of deposits (at both hot and cold temperatures), optimum care for classic engines and excellent compatibility with the special materials found in these engines such as cork seals or leaded bearing shells.

[neilbardsley]

This 20W-50 Porsche Classic Motor Oil is specially adapted to the early air-cooled models for all 356, 914 and 911 models with a displacement of up to 2.7 liters. This mineral oil is available in 1 or 5-liter cans.

For all 356, 914 and 911 models up to the 2.7-liter G-Model, Porsche recommends the multi-grade version with a viscosity of 20W-50. Back in the 1950s, 1960s and 1970s, engines were built with much more generous tolerances than today, which is why the viscosity of an oil must be low enough for it to penetrate into all areas of the engine as quickly and uniformly as possible during cold starts. At the same time, however, its viscosity must not be so low that a stable lubricating film is no longer present when the engine heats up. The developers went to particular lengths to achieve excellent cold start properties for the oil, so that the engine can be lubricated as quickly as possible when started. The CCS test was especially important in this respect, since it simulates the behavior of the oil in the crankshaft bearing during cold starts and at low temperatures.

The Porsche Classic 20W-50 is a mineral oil known as a hydrocracked base oil with mildly alloyed additives. Hydrocracked base oils are characterized by a very low level of contaminants, a very low sulphur content and very good oxidation and aging stability, which prevents deposits, for example. At the same time, the Porsche Classic Motor Oil 20W-50 has an extremely high HTHS viscosity (High Temperature, High Shear), which describes the quality of the engine oil at high temperatures (150 °C) in the lubricating gap and with high shear rate (engine speeds). Finally, the excellent shear stability ensures that the optimum lubricating properties are reliably retained at high engine temperatures, even after long periods of operation and under high loads.

In a nutshell: low levels of deposits (at both hot and cold temperatures), optimum care for classic engines and excellent compatibility with the special materials found in these engines such as cork seals or leaded bearing shells.

There is a real lack of technical data on that oil. What is the Viscosity Index, zddp content, flash point etc! That would put me off using it.

[mycar]

The ignition temperature is a deciding factor when choosing motor oil ?

[Ashley James]

Given US owners and PRS’s preference for VR1 Porsche’s classic oil would be a good marketing department choice and you could argue that owners probably won’t benefit from more expensive 10W60 fully synthetic oil. Also with all the old wive’s tales swishing around the internet, Eric the Car Guy anyone, it’d be a more difficult sale.

I’m sure no one would put a 0w30 in an old air cooled engine though old water cooled ones were supposed to use SAE30 in summer and 20 in winter till oil consumption increased when 40 took over. This was until Duckhams produced the first multgrade 20/50 and everyone switched. Until then oils had to be too thick cold to be thick enough when they were hot.

[Ashley James]

The ignition temperature is a deciding factor when choosing motor oil ?

About 75% of the petrol you burn is wasted heating the engine and water is a better coolant as anyone who swims will tell you. Air cooled engines often get hotter hence thicker oils are needed when this happens.

I think ignition temperature is fairly constant or should be if the mixture and timing are, so probably not a factor in oil viscosity selection, which is more to do with temp and shear strength of the crank bearings, cam/tappet protection and cylinder walls/piston cooling etc.

[mycar]

I think Neil was referring to the ignition temperature/flashpoint of the engine oil itself.

I was wondering how important that would be when deciding which oil to use.

[neilbardsley]

I think Neil was referring to the ignition temperature/flashpoint of the engine oil itself.

I was wondering how important that would be when deciding which oil to use.

My take on this was How stable is the oil v index? What temp does it stop being a lubricant - flash point? How much zddp does the oil have?

[mycar]

You're probably right to be wary of this product.... but I wonder, what if a company, one of the most successful engineering companies in the history of mankind, (the same company that designed and built your engine) produced a oil that was specifically designed to be used in that engine ?

What if this oil had been 'subjected to extensive laboratory and road tests to prove its running and lubricating characteristics'.

What if this magical substance was freely available ?

Why would you question its suitability ?

Don't get me wrong, I don't have shares in Porsche oil but there's an awful lot of guff spoken about oil on the internet.

If in doubt, why wouldn't you be happy to take Porsche's word for it ?

[neilbardsley]

"produced a oil"

Porsche didn't! It's relabel from another company

"f in doubt, why wouldn't you be happy to take Porsche's word for it?"

This is the bit a struggle with!

However, almost all the oils we have mentioned will do the job well if changed regularly.

[alastairp]

You're probably right to be wary of this product.... but I wonder, what if a company, one of the most successful engineering companies in the history of mankind, (the same company that designed and built your engine) produced a oil that was specifically designed to be used in that engine ?

What if this oil had been 'subjected to extensive laboratory and road tests to prove its running and lubricating characteristics'.

What if this magical substance was freely available ?

Why would you question its suitability ?

Don't get me wrong, I don't have shares in Porsche oil but there's an awful lot of guff spoken about oil on the internet.

If in doubt, why wouldn't you be happy to take Porsche's word for it ?

Would this be an opportune moment to raise the issue of N-rated tyres..........

[corner shop]

This 20W-50 Porsche Classic Motor Oil is specially adapted to the early air-cooled models for all 356, 914 and 911 models with a displacement of up to 2.7 liters. This mineral oil is available in 1 or 5-liter cans.

For all 356, 914 and 911 models up to the 2.7-liter G-Model, Porsche recommends the multi-grade version with a viscosity of 20W-50. Back in the 1950s, 1960s and 1970s, engines were built with much more generous tolerances than today, which is why the viscosity of an oil must be low enough for it to penetrate into all areas of the engine as quickly and uniformly as possible during cold starts. At the same time, however, its viscosity must not be so low that a stable lubricating film is no longer present when the engine heats up. The developers went to particular lengths to achieve excellent cold start properties for the oil, so that the engine can be lubricated as quickly as possible when started. The CCS test was especially important in this respect, since it simulates the behavior of the oil in the crankshaft bearing during cold starts and at low temperatures.

The Porsche Classic 20W-50 is a mineral oil known as a hydrocracked base oil with mildly alloyed additives. Hydrocracked base oils are characterized by a very low level of contaminants, a very low sulphur content and very good oxidation and aging stability, which prevents deposits, for example. At the same time, the Porsche Classic Motor Oil 20W-50 has an extremely high HTHS viscosity (High Temperature, High Shear), which describes the quality of the engine oil at high temperatures (150 °C) in the lubricating gap and with high shear rate (engine speeds). Finally, the excellent shear stability ensures that the optimum lubricating properties are reliably retained at high engine temperatures, even after long periods of operation and under high loads.

In a nutshell: low levels of deposits (at both hot and cold temperatures), optimum care for classic engines and excellent compatibility with the special materials found in these engines such as cork seals or leaded bearing shells.

There is a real lack of technical data on that oil. What is the Viscosity Index, zddp content, flash point etc! That would put me off using it.

an oil analysis undertaken here - https://symphonyofshrapnel.blogspot.com ... ?q=porsche

if you're hooked on ZDDP, you may be disappointed

[hot66]

Porsche stuff just rebranded

[mycar]

However, almost all the oils we have mentioned will do the job well if changed regularly.

And this is your considered opinion ?

After all your fretting about zddp content, viscosity index, flash point and oil v index stability I felt sure you'd be more specific in your recommendation.

[Bruce M]

I’ll just leave this here...


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