Delvac 1 5w-40 '89 Porsche 928

[Doug Hillary]

Porsche 928S4 - 320hp - 32v water cooled V8
Vehicle used 10% city, 30% urban, 60% country
Oil used = Mobil Delvac 1 - 5w-40 (CH-4/SJ)
Distance on engine = 76090 miles
Distance on oil = 5049 miles
Distance on MANN filter = 5049 miles
Time on oil & filters = 6 months
Top up oil required = nil
Temperatures in period = Low of 18C to High 40C+
Humidity in period = 98% max

Note;
Column 1 = this UOA
Column 2 = the average of all six UOA's on this engine over 18 months and 13475 miles - the first 12 months ( 8426 miles ) and four UOA's on Shell's synthetic Helix Ultra 15w-50

Viscosity @ 40C 86 - NA
Soot Index 0.1 - 0.0
TAN 3.5 - 2.56
PQ Index
Iron 7 - 7
Aluminium 4 - 3
Chrome 1 - Copper 2 - 4
Lead 5 - 5
Silicon 6 - 9
Sodium 1 - 3
Water
This oil was NOT changed at this Sample point as the vehicle is on annual oil drains or via UOA

I welcome your comments

Doug

 

[buster]

Excellent numbers. I'd be happy with those.

 

[Al]

I was a little confused about the "average" milage on the other oils. Was it 13,475 miles or 13,475 miles/6 ???

 

[Doug Hillary]

Hi Al,

the averages column covers a total of 13475 miles
and during this distance there has been six UOA's done including this latest one

Shell Helix Ultra was in the engine for 8426 miles of this distance, over a period of 12 months

The UOA's where taken as follows;

1 - after six months (Helix 4097 miles)
2 - after eight months (Helix 5165 miles)
3 - after nine months (Helix 7039 miles)
4 - at OC at around 12 months (Helix 8426 miles)
5 - at 14 months (Del 1 3375 & 11801 miles)
6 - at 18 months ( Del 1 5049 miles - the 13475 miles point)

Regards

Regards

 

[Patman]

Very nice! Assuming you drive that car the way it was meant to be driven (full throttle!) then it is extremely impressive! Delvac 1 is a good match.

 

[Doug Hillary]

Hi Patman,

yes the engine has responded very well to the sightly lighter viscosity oil. I even think that you may have suggested this move here about a year or so ago

Since being on Del 1 the car has been driven for long distances at 100mph. It has seen 5k on the rev counter often. It is our summer of course and much of its use is in ambient temps of 33C+ and with very high humidity ( 98% at present )

Thanks and Regards

 

[Al]

Thanks for the clarification. Its apparant that this oil is as good as the 50 wt in protecting your engine. The average interval sampled was 5525 miles so this interval is say 10% short of average. So this comparison is very valid.