I recently got a used oil analysis from Blackstone for a 2013 C4S. Based off the analysis, is there anything you guys would change (change to 5w/50, shorter interval)? I noticed the iron levels are much higher than average.

Oil used: Mobil1 0w/40
Miles on oil: 8000 miles
Miles on car: 27,000 miles



2013 Porsche C4S UOA

 

Change every 5,000 miles.
Don't use Mobil 0W40.
Don't exceed 4,000 rpm until oil is at operating temperature.

Start there. Retest at next interval and post in this same thread this summer.

That's a TON of iron. My iron is 4 ppm for 6,000 miles on Mobil 5W50 and 50,000 miles on the motor.

Search my scree name and you can see my entire UOA history on my 991 for the past 4 years.

 

Following LexVan's prior posts on oil and the Blackstone reports I started doing them too. This one shows my last two reports for the sake of comparison. Note on the older one below I was running Mobil 1 0w/40 European Formula and the viscosity reading was lower than desired. Based on that and LexVan's prior posts, I changed to Mobil 1 5w/50 and got more acceptable viscosity readings on the more recent reports.

Your iron is certainly much higher than mine, but my most recent one may be helped by the relatively low miles and time between change.

The thing that really strikes me on your report is the low readings on Molybdenum and Boron are low. Compare them to the recommended values and the ones in my report. These are additives that help reduce wear (along with Phosphorous which seems to be okay). I don't know why they would be so low on your report. Maybe this would help explain the high iron? I don't know.

Did you do the oil change yourself or see what was used? I find myself wondering if the oil was actually Mobil 1 with the low additive readings. Of course there could be a perfectly good explanation, but I can't readily think of another reason they would be so low, three to four times less than my readings.

One last thing I noticed is that your fuel percentage is within range but more than twice mine. This may indicate more short drives and less long drives with the oil staying at a lower temperature overall and cooking off less water/fuel. But then I see your water reading is zero, so maybe that isn't it.

 

tc4s, here are my reports:

https://rennlist.com/forums/991/810337-used-oil-analysis-on-991-a.html

Reminds me that I need to add my Fall 2017 report.

What part of the country are you in?

This is only one UOA. Keep doing them. We don't know if your Iron is going up or coming down.

 

Thanks for the suggestions. I'm in the San Francisco Bay Area, and I had my last oil change done by the dealership which showed Mobil1 0w-40 on my invoice.

I'll change out this oil around 5000 miles, and I'll switch to Mobil1 5w-50 for my next oil change. Hopefully I have better looking iron levels in my next report.

 

What kind of driving do you do if I may ask? Short trips? How many miles a year?

 

Commute time ranges between 25 - 45 minutes. 15 miles to and from work from Monday-Friday. On the weekends, I'll have some short trips (10 minute trips that are about 2 miles). Yearly mileage is between 6000-7000 miles.

 

Good plan. I can't wait to see your next UOA with 5,000 miles. Iron should drop about 8-10 ppm. Then with the swith to Mobil 5W50 I'd bet it drops another 5-7 ppm and starts to settle in at about 10-12 ppm total. Let's see.

 

I had the same iron level as you, 25 ppm, with my first GTS analysis. In oil that, based on previous owner's schedule, had gone close to 8000 miles. Blackstone thought that was OK given the OA mileage on the car, mileage on the oil and the fact that it was only the 2nd change overall. I've always shown iron in the 14-15 ppm range on the 2 Caymans I've had tested but that was based on more frequent changes. If iron goes up on the next change with less miles I'll be concerned.

 

Lex - your question on where the OP lived made me wonder about different oil specs based on climate. I am in Houston, would your 5W50 recommendation hold here as well, or would you suggest something different because we are so hot for so much of the year?

 

Mobil 5W50 would be a great choice for Houston, year round. People in the snow-belt or artic should run a 0W40 if they plan to run in the winter.

5W50 is the highest viscosity that's A40 approved for hot climate driving with the 991.

 

5W50 for Houston.

sean

 

 

Hoping to get some feedback on my Blackstone UOA.

My car is a '17 C2 7MT. It was sold by Porsche South Shore in Freeport NY August of '17. The dealer serviced the car May '18 (8,607 miles) and April '19 (18,544 miles). I bought it June '19 as a CPO from the same dealer, with 18,956 miles, and drove it home to Tampa.

I did my first oil service last Feb '20 (25,153 miles) with Mobil 1 0W-40, since I was getting antsy about the OCI going over 5,000 miles. I just did my second change last month at 28,706 miles, based on time, using Mobil 1 5W-50. I used Mahle filters both times. Based on what I understand about the viscosity comment from Blackstone, it was probably a good move to go to the 5W-50.

I'm not exactly a chemist, so any thoughts on my used oil analysis would be appreciated.

 

Looks like a fine report. Your wear metals look good with the 0W40, so while a tiny bit thin, it wasn’t hurting at all. It’ll be interesting to see how your wear metals change with the 0W50.