Best engine oil for 964?
11-30-2016, 02:11 PM
#65
RL Technical Advisor
I much prefer a 15w-40, 15w-50, or 20w-50 for these air-cooled engines unless one is operating in arctic conditions.
11-30-2016, 04:58 PM
#66
Track Day
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The search function at this UK website enables you to get recommendations specifically for our engines:
http://www.opieoils.co.uk/
There's a range of leading global brands and some specialist producers. All recommendations for the 3.6 engine are 5W40 oils.
http://www.opieoils.co.uk/
There's a range of leading global brands and some specialist producers. All recommendations for the 3.6 engine are 5W40 oils.
12-01-2016, 12:42 AM
#67
Drifting
I agree with Steve's recommendations. 5W40 is too light for air cooled motors. Even the oils designed by Porsche for their air cooled motors are either 10W50 or 20W60. Not that I use their classic oil, as I feel it is over-priced.
12-01-2016, 05:33 AM
#68
Why should a 40 be too light? I've never seen my oil's temperature rise over 120°, even after hard mountain driving.
If I understand correctly, the right viscosity should be 10 CST @ operating temperature, so 40 should be just perfect.
Also, with 50 grade oil, I used to read 5 bars of oil pressure at little more than 2000 rpm, which appears too high to guarantee a good flow... Now, with a 40 grade oil, I read 5 bars @ 3500-4000 rpm, numbers that look better to me...
Outside temperature where I live: 0-40 celsius.
Steve, please, explain me where I'm wrong!
If I understand correctly, the right viscosity should be 10 CST @ operating temperature, so 40 should be just perfect.
Also, with 50 grade oil, I used to read 5 bars of oil pressure at little more than 2000 rpm, which appears too high to guarantee a good flow... Now, with a 40 grade oil, I read 5 bars @ 3500-4000 rpm, numbers that look better to me...
Outside temperature where I live: 0-40 celsius.
Steve, please, explain me where I'm wrong!
12-01-2016, 12:06 PM
#69
Three Wheelin'
Why should a 40 be too light? I've never seen my oil's temperature rise over 120°, even after hard mountain driving.
If I understand correctly, the right viscosity should be 10 CST @ operating temperature, so 40 should be just perfect.
Also, with 50 grade oil, I used to read 5 bars of oil pressure at little more than 2000 rpm, which appears too high to guarantee a good flow... Now, with a 40 grade oil, I read 5 bars @ 3500-4000 rpm, numbers that look better to me...
Outside temperature where I live: 0-40 celsius.
Steve, please, explain me where I'm wrong!
If I understand correctly, the right viscosity should be 10 CST @ operating temperature, so 40 should be just perfect.
Also, with 50 grade oil, I used to read 5 bars of oil pressure at little more than 2000 rpm, which appears too high to guarantee a good flow... Now, with a 40 grade oil, I read 5 bars @ 3500-4000 rpm, numbers that look better to me...
Outside temperature where I live: 0-40 celsius.
Steve, please, explain me where I'm wrong!
12-01-2016, 02:32 PM
#71
AIr cooled engines have higher tolerances than the new generation water cooled engines. They need this because they have a broader operating temperature range and more thermal expansion. Anything lighter than 15w at cold startup will not protect the wear surfaces at startup and will leak more.
12-01-2016, 03:40 PM
#72
Technical Guru
Rennlist Member
Rennlist Member
AIr cooled engines have higher tolerances than the new generation water cooled engines. They need this because they have a broader operating temperature range and more thermal expansion. Anything lighter than 15w at cold startup will not protect the wear surfaces at startup and will leak more.
12-01-2016, 04:17 PM
#73
Please, next time get more informed before writing.
AFA leaks, I only care about my engine's protection, even if this means some leaks...
12-01-2016, 04:20 PM
#74
12-01-2016, 07:46 PM
#75
Rennlist Member
I think every oil thread ends up like this, so I don’t know why I’m posting. Possibly confirmation bias to protect the ‘investment’ in 28 litres of Mobil 1 Racing 4T 10W 40 
Porsche recommended fully synthetic 5W 40 for my car.
The higher the viscosity the thicker the oil.
5W 40 means that when at 0F the oil flows like an oil with a viscosity grade of 5 and when at 212F it flows like an oil with a viscosity of 40.
The thinner viscosity at lower temperatures reduces engine wear at start up whereas the viscosity grade at operating temperatures is ideally at what the factory tested as appropriate.
I selected Mobil 1 Racing 4T because of a Porsche racing mechanic recommendation. The higher ZDDP levels are apparently good for air cooled engines.
As there is no local supply of Mobil 1 Racing 4T 5W 40 I either have to accept 10W 40 may increase start up wear or find a 5W 40 with similar ZDDP levels.
The latter appears more difficult so I’ll run the risk in my temperate climate. Bias confirmed
Porsche recommended fully synthetic 5W 40 for my car.
The higher the viscosity the thicker the oil.
5W 40 means that when at 0F the oil flows like an oil with a viscosity grade of 5 and when at 212F it flows like an oil with a viscosity of 40.
The thinner viscosity at lower temperatures reduces engine wear at start up whereas the viscosity grade at operating temperatures is ideally at what the factory tested as appropriate.
I selected Mobil 1 Racing 4T because of a Porsche racing mechanic recommendation. The higher ZDDP levels are apparently good for air cooled engines.
As there is no local supply of Mobil 1 Racing 4T 5W 40 I either have to accept 10W 40 may increase start up wear or find a 5W 40 with similar ZDDP levels.
The latter appears more difficult so I’ll run the risk in my temperate climate. Bias confirmed