No HTwo O

Sorry for the delay. Several here have wanted to see my UOA's. Here is my most recent report from the Turbo's oil change in late October 2011.

A little history, first. I'm pretty sure my Turbo had a steady diet of Mobil 1's 15W50. I know Thomas used this oil during his ownership, and my receipts and history going back to day #1 also indicate this oil was used too.

This was my 5th oil change in 2 years. When I brought the car home (11/20/09 report), we did an oil change with Mobil 15W50 (gold cap extended perf.). And again on 5/25/10 for oil change #2.

After much reading on Rennlist and listening to Kevin's recommendation for Mobil V-Twin 20W50 I made the switch and we start seeing the improvements in my UOA's with report #3 from 10/29/10.

Zinc, phosphorus and viscosity levels have all come up nicely with the V-Twin, and wear metals have dropped.

According to Blackstone the Universal Average is for approximately 3,400 miles on the oil change interval. I run my oil to about 5,000 miles average. Blackstone has 22 active cars (3.6L Turbo engines, like mine/ours) in the sample pool.

I plan to stay with the V-Twin and the only change I may (not sure) make is to change the oil closer to the 4,000 mile mark, as this was the best report I had for wear metals (5/12/11 report #4).

jimbo3

Thanks for the report. I had considered using V-Twin, but shyed away from it due to the potential for the extra additives to adversely affect the cats. Maybe a 50/50 mix of "regular" Mobil 1 15-50 and V-Twin 20-50 might be a good mix to bring ZDDP and other additives up, but not too much?

I'm sticking with Brad Penn 20-50 for now.

No HTwo O

Jim, a few guys are doing the blend, like you.

This was a concern off mine too, but Kevin dismissed it, and I am good with that.

Brad Penn is an excellent choice, too, and guys like Spartan and Wagongotya run this oil in their track monster (changed after each event).

EntropyChaser993

Thanks for posting. These kinds of analysis reports are useful.

No HTwo O

I agree. Especially when you decide to make a change. Like a change in oil brand, or viscosity, or change interval. The reports help you understand if the change made an improvement, or not.

For example, for about 4 years I ran Red Line 5W40 in the Boxster with great results. I recenly change to Mobil 1's 5W50 (hard to find oil). After 2 driving season with the 5W50 Mobil I can see an improvement over an already quality oil and excellent reports. IMO, if I had not been doing the reports over the years, I'd never know if my selection was "validated".

Here is the Boxster's recent report:

EntropyChaser993

This thread is so much better than the "what oil should I use" ones.
I plan to start doing this with my next oil change.

No HTwo O

True on point #1. And smart move on point #2.

Glenn Evans

It will be interesting to see whether the iron readings go up again after another interval on the low ZDDP oil. This UOA for a Boxster run on low ZDDP oil was posted earlier this year, with a higher iron reading: https://rennlist.com/forums/993-foru...-analysis.html

AC/911's

Just called local Autozone, said they had over 12 quarts in stock, $9.99 each, not bad.

Glenn Evans

According to
http://www.mobil.com/usa-english/mot...duct_guide.pdf Mobil 1 5W-50 has 1100ppm of zinc and 1000ppm of phosphorus. Your UOA levels of 1020 and 865 are well under this.

As far as I am aware, previous versions of that product guide have stated that 5W-50 has 1000ppm phosphorus, so your low levels of zinc and phosphorus are unlikely to be because the oil you used a year ago was supposed to be lower in Zn and P. Steve Weiner advocates testing new oil to validate zinc and phosphorus levels.

The ratio of Zn to P in the anti-wear additive ZDDP is 1.056:1 by weight, so the ZDDP content indicated by your oil sample's P level is equivalent to only 913ppm of Zn.

No HTwo O

Not sure I see your point. You are comparing apples to oranges.

Yes, a virgin oil sample of Mobil 5W50 may be 1100ppm zinc and 1000 ppm phosphorus but one would expect these levels to drop after +5,000 miles, as the Used Oil Analysis is showing.

TB993tt

Guys, I heard people did this oil analysis thing but geeez this is a whole new level of geekiness and H20 you are saying that some people change their oil every 3400miles on average ?

What exactly is the goal of all this apart from being ultra geeky, which I admit I am partial to about some things but why the forensics, surely if the motor wears and leak downs get too high it is 3.8 time, smiles all round, these are not throw away non Mezger engines, bolt on some new bigger and better bits and you're good to go.

Mike J

The reason is to find the oil that gives the engine the best chance of longevity. While you might be able to just throw money at a 3.8l conversion, some of us try to really enjoy what they have, and any cheap choice (ie. which oil we choose) can make a difference , why not?

Cheers,

Mike

No HTwo O

I am a geek, yes I am.


As to your question, yes, Blackstone has Universal Averages for the 3.6 Turbo motor (22 different units at this time) and the average miles drive between oil changes is approx 3,400 miles.

TB993tt

Geek is good

3400 miles is plain barking mad IMVHO, does no-one actually drive these 22 cars or is it a case of lusting after the next set of oil analysis figures in an OCD sort of way