Doug Hillary

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

Marc Schwager

Good info. This proves even oil likes life in the Whitsundays!

Doug Hillary

Hi Marc, ( my son's name spelling too )

I really love the SF Bay area too - and the Napa Valley wines - great place

Regards

Ell

Looking at this, you can get a good 15000 miles on an oil change. When you drive cars that hold massive amounts of oil, this is good to know. Thanks for your information.

tekwaldo

Would there be a time factor to worry about? It could take me 3-4 years to put on that kind of mileage.

Doug Hillary

Hi,

tekwaldo - oil changes should be distance or time based ( or engine hours, or fuel used ). Porsche say either 20000 kms or 12 monthe whichever is reached first or, whatever is in the Handbook for your car

With my heavy Detroit Diesel powered trucks, 12 months would equal about 240000 kms - I change their engine's oil every 100000 kms

Regards

Old & New

Doug,

With a recommendation of 10000 miles and your data indicating a useful oil life of 16700 miles, there is apparently little grounds for 3000 mile oil change intervals under normal driving conditions... unless one takes some pleasure in squandering our natural resources.

How long do you intend to keep the oil in the car? Will you test it beyond 10000 miles if the numbers keep looking good?

Jim bailey - 928 International

Doug I believe you are the first to post real facts about oil . No rumor , marketing hyp , self serving "recomendations", beliefs , myths ......... just real information from a real person.......Thank You

Gretch

Doug, that statistic translates to every 60,000 miles on your Diesels. I run a couple of big tractors that hold large quantities of oil and I use the higher performance Diesel oil. The oil change recommendations are for 200 hours max (100 hours in harsh conditions) which translates to about 12,000 miles. How do your detroits hold up for such a long time between oil changes?......

Doug Hillary

Hi,
Jim,
thanks for your comments

Old & New,
I will drain the oil regardless at around the one year mark. It is best to do an annual change if the distance is not met. I may put it on to Mobil Delvac 1 then to standardise the oil stocks. My Subaru, BMW and light and heavy trucks are already on this oil

Gretch,
Detroit did not like it much when we commenced long drain intervals in 1992. They talked about "breaching warranty" isuues. Castrol's 15w-40 RX Super was sampled at 20000 kms and we settled on 25000 oil changes ( OC ) ( a CG oil ) - Detroit recommend 15000 kms in Australia.
In 1995 Castrol introduced a CH semi-synthetic "Enduro LD" a great product, and with analysis we went out to 40000kms. Castrol gauranteed the results and the warranty - it worked well
In 1999 we moved to ExxonMobil's Delvac 1 5w-40 ( CH4 ) on an economics basis ( at 80000 kms OC minimum ). After some extensive sampling on a number of engines we settled on 100000 kms OCs. The oil will go a lot further - I won't.
Detroit now recognise that using a professional servicing approach is cost effective. They have been amazed at how internally clean our engines are.
Warranty is no longer an issue as our records are extensive and accurate
Average oil consumption is about 1 ltr per 6300 kms
I do fit a Spinner 2 by-pass centrifuge filter when the trucks are new and this is cleaned at every second oil change. I only use expensive Donaldson ELF long life filters which stay in place for the 100000 kms
For your interest my trucks average 80 km/h - speedo distance/against hour meter - for whole of life. A 1250 hours OC cycle
I always sell my vehicles with about 1-1.3 million kms on them with full service records

I no longer sample the trucks unless we are looking for a mechanical problem - I have an extensive database on wear metal trends with Detroit 60s

I hope this is of interest

Regards

Randy_J

Doug, hope you don't mind, but I posted this report #3 on the 944 Forum - so much debate about oil changes on that forum and people are getting completely paranoid now with one owner claiming 1500 mile (!) oil change intervals!

Your methodical reports will put some people at ease. I've taken to changing Mobil 1 15W50 every 8,000 miles and changing the OEM Mahle filters every 4,000 miles (only $4 a piece from eBay!). Still that only works out to 12 mos / 6 mos changes.

Thanks for all the great reports and relaying the experiences with your fleet.

Doug Hillary

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

Gretch

Doug,

I will say it is of interest!!!!!!!!!!!

I have posted the results on the wall of the shop for reference. I am rabid about oiling the hardware, including grease fittings. My equipment application is agricultural and a burnt spindal can ruin a whole weeks worth of planned work. I now have the confidence I needed to run my diesels to 200 hours without feeling guilty.

Every high oil capacity machine in the fleet (including my P cars) now run mobil one. Now if I could get a high capacity oil pan for my Tahoe.........

I too have distributed your results to my "car" buddies. Thanks for sharing the information with us.

SteveG

Your independent report is welcome. Even Click and Clack said years ago that 3000 miles was ridiculously low. My other cars are/were Honda with over 200K on each and going strong, were changed at 5-6K with no issues. I'm so tired of being lied to by entities whose profit motives outweigh "truth and the American way." -- partial quote = Clark Kent.

chris928

interesting article

http://www.amsoil.com/lit/lng_article/march_lng_new.pdf

http://www.amsoil.com/lit/lng_article/march_lng_new.pdf