Randy_J

For those of you who have not seen Doug Hillary's posts on Oil Condition in the 928 Forum, it's really worth the read:
Thanks Doug!

Hi,
This is the third report on the oil in my car - at nine ( 9) months.
The testing was commenced six months ago to confirm the oil change recommendations from Porsche namely - 20000kms or 12 months for "normal" use
This sample was taken nine months after the oil and filter were changed

Details:

Car - MY89 - 928S4 Auto
Speedo - 114848kms
Oil - Shell Helix Ultra 15w-50 - SJ/CF, A3-96/B3-96 - fully synthetic
Oil/filter change date - 10/17/02
Distance since Oil/filter changed - 11333kms
Oil used since fill - nil
Date of this sample - 7/14/03
Distance since last sample - 3017kms
Use in period - 15% town,25% urban,60% hiway
Avg speed in period - 69 km/h
Fuel economy in period - 11.8ltr-100km
Ambient in period - 26c high to 4c low
Humidity in period - 98% highest
OIl Condition - "use" factors;

Note - last report figures below are shown thus: newest-last-oldest

Viscosity - OK - 98-98-94 ( excellent )
Water - OK - 0.05%-0.01%-0.00% ( excellent )
Soot Index - OK - 0.00-0.00-0.01 ( excellent )
TAN - OK - 4.6-2.6-3.2 ( very good ) the Max allowed is 8.9

Lab. Report Summary

ExxonMobil's rating - "Normal"
Status-Excellent for continued use
Last Report - "Normal"
Estimate of distance remaining to oil change - 3700kms ( 2300 miles ) 3 months
Estimate of distance of oil life left to change - 15000kms ( 9500 miles )
Estimate of total distance to end of oil life - 27000kms ( 16700 miles )

Elemental Analysis;

Iron - 9-7-6 ( excellent )
Aluminium - 3-2-3 ( excellent )
Chromium - 1-<1-1 ( excellent )
Copper - 8-5-3 ( very good )
Lead - 7-4-4 ( very good )
Silicon - 5-11-22 ( excellent )
Sodium - 2-2-5 ( excellent )

Note: None of the elemental movements are significant

The oil has survived for 11333kms (7038 miles) and nine months very well. Porsche's recommendations are looking very very good and with a big margin too!!
Regards


__________________
Doug Hillary
Rennlist Member # 030204-2681
MY1989 928S4 Auto-Diamond Blue
MY1998 BMW Z3 2.8 Manual
My2002 Subaru Outback 2.5 Manual

Randy_J

Doug replied on the 928 forum:
Hi Randy,

Thanks, I hope it all helps

Mobil 1 15w-50 is a great oil Randy, it has a very good low temperature pour point ( about -51C ) and an excellent high shear viscosity at 150C too
This oil will easily do what you intend, and with a big margin

Next time you are in OZ you could take some M1 5w-50 home with you - it would be an excellent oil for your winter

Currently there is an independent test on M1 5-30 in the USA - in a GM 5.7 V8 - that has run easily to 14000 miles and is still within spec. It is still going strong

Regards


__________________
Doug Hillary
Rennlist Member # 030204-2681
MY1989 928S4 Auto-Diamond Blue
MY1998 BMW Z3 2.8 Manual
My2002 Subaru Outback 2.5 Manual

Randy_J

hmmm...

Randy_J

hmmm... replying to all my OWN POSTS but this is well worth reading from the 928 forum:

chris928
User
Registered: Jun 2002
Location: ventura ca
Posts: 239

http://www.amsoil.com/lit/lng_article/march_lng_new.pdf
__________________
chris
'85 928S
5 speed
white
170K miles

adrial

3 cheers for Amsoil! If anybody here needs any I can get it for you cheaper.

Peckster

Very interesting. Sounds like I could get a year out of my Mobil 1 too. My mehanic prefers to use 10/40 dino and change it every three months, but then he has a vested interest.

Randy_J

Here's the link to the 1,000 mile interval study on a Camaro running Mobil 1

http://neptune.spacebears.com/cars/s.../oil-life.html

Thanks to Doug Hillary for the link. Bottom line, change the oil filter but you can keep that synthetic oil in the engine for a lot longer than 3,000 miles! Save a lot of $$ and save the environment!

crushingday

Adrial. I have been using Mobil 1 15-50 in my 968. I have not tried the Amsoil. How much does it cost?
Thanks
Ross T

adrial

http://intershop.amsoil.com/cgi-bin/...1/Catalog/1108

I use series 2000 20-50 racing oil for spring/summer/fall.

Standard high performance 20-50 may be all that you need.

I may be able to get it to you for $1/quart less...have to look into it.

--Adrial