Brad, when you get your UOA results, please post them in my "Used Oil Analysis" post. Thanks! More data, the better.

Don't use 15W50 in the 991. But, if you wanted to consolidate down to one oil, you could use the 5W50 in both cars. Ideally you should really be using two oils for both cars. I'd suggest you start running Mobil V-Twin 20W50 in your 993. Easy to find. Everywhere. In the motorcycle oil aisle.

If you really-really want the 5W50 in the future, I could always drop of a few cases for you with my good pricing. I'm in St. Louis a few times a year for business & fun. Or, I can tell you how to maybe get/find a Mobil distributor in your area, and open your own account for local purchases and pick up.

Many years ago I contacted Mobil, and they gave me PetroLiance as the contact for 5W50 purchases, since no one easily offers it retail. I contacted them, and opened my own account for local will-call pickups and purchases. It was so many years ago, I don't remember the details.

http://www.petroliance.com/mobil-distributor-locations

 

Thanks for the info...and your kind offer. I'll definitely keep that in mind. (I get north to Chicago a few times a year as well. And to Autobahn in Joliet at least twice a summer.)

I'll stick to different oils in the two cars. Have used M1 15w50 in the 993 for over 10 years so will stick with that. Very easy to find locally. And for the next change in the 991 I will run 0w40 and do a UOA afterwards.

I plan to change the oil in my 991 for the very first time this coming week. I wonder if it's worthwhile doing a UOA on that now? 3000 miles and one DE on the car. (My Blackstone vials came in the mail yesterday!)

BTW, a friend runs M1 0w40 in his 991 and gets stellar reports from Blackstone. He does a few DE's a season as I plan to. Will be interesting to see how my results vary.

 

Please do the UOA.

 

Aside from rabid curiosity, has anyone actually ever found anything on an oil analysis that saved the day? Or more importantly, discovered something big that was then fixed under warranty?

 

Ok, will do. I have never done one before. How quickly do they get the results back to you?

 

The slowest part is the US Mail service. I've been using UPS with much greater success.

They email the test results to you the same day.

I've seen results in as little as 3 days from shipping. Longest was almost 2 weeks.

 

No, but then again how often do we see engine failures. Pretty rare. 996s maybe a different story.

I use the UOAs to confirm oil selection and drain intervals. Mainly.

 

i think 5w-50 is a motorsport oil

 

Are you saying racing oil? Not a racing oil. That's for sure.