First Blackstone Report
 

I was a little nervous about what the results would be. But I'm pretty pleased with this report. Whew! :)

1997 with 47,000 mile. I bought it about 2 years ago, with 36,000 miles.

https://i.imgur.com/opge42M.jpeg

Looks good to me as well. Would not use 0W-40 for 5.000 mls, stick to 5W-50 what is btw the recommendation from Porsche for these engines (now).

I didn't know that 5W-50 was recommended. Thanks! I guess I need to do another oil change.

Yes, 996 + 986 have a (Classic) Porsche recommendation for 5W-50, I would use a quality fully synthetic brand. They even have a number for 1l, PCG-043-210-40.

No need to buy this extreme expensive stuff ;-)

Edit: Full/High SAPS

As 997_996 says, when Porsche's developed their "classic" oil for the 986, they chose 5w50. Probably has to do with age and wear of these engines in general now. A lot of 0w40 and 5w40 oils are still on the approved list of porsche. The most important is choosing a A40 approved oil, next is choosing a quality oil that has some proven performance over time.

A 0w40 oil should still be fine, allthou It is said to avoid the mobil 0w40 because it shears and looses viscosity quickly. I choose mobil 5w40 instead with some ceratec added. I suspect other 0w40 oils like castrol is higher quality.

Mobil does have a 5w50 oil now with porsche A40 spec. The Mobil 1 Peak Life 5W-50. I'm running a low temp thermostat which lowers oil temps and live in northern europe, so I will stick with 5w40 unless it starts consuming oil.

Got my car back from the indy now, and they used Castrol 0w40. I will run with this until next oilchange.

i don't understand how a low temp thermostat allows lower oil temps, isnt it just it just go wide open sooner on the warm up ? I imagine low and regular temp thermostats are both fully open when car warms up after first 5 minutes no ?

This is from the LN Engineering website, in the section describing their spin on filter adapter:
"Oil change interval should not exceed 6 months or 5,000 miles for street using a 0w40 or 5w40 viscosity motor oil... higher viscosity is not recommended".

Is that only for a spin on filter or is this outdated info?

It doesn't. Period. Fully open.

And, yes.

Math and science. :cheers: