An Editorial by dieselmann
Volume 11; April 01: Diesel Motor Oil Comparison

The argument over which motor oil is best keeps surfacing. With this last go-around I spent some time getting product specification sheets of some of the oils that have the correct API service ratings for the PowerStroke.

All of the oils below excede the required API ratings of CF-4/SH by being rated CH-4/SJ. They also excede Ford's recommendation of Mack service rating EO-L--Mobil Delvac 1300 Super and Valvoline All-Fleet Plus are EO-M, all others are EO-M Plus.

None of the oils in the table are significantly better than the others over-all, but some are superior in critical areas than others. The high pour point of the Rotella T would make it less suitable for colder temperatures. Likewise the high Cold Cranking Viscosity of the Penzoil Long-Life.

But, to give Shell credit, Rotella T has a higher Viscosity Index than a majority of the other conventional oils.

Some manufacturers did not have product information available on-line (including Motorcraft--I got those from Ford), so they are not included in the following table. This information is not ment to make anyone change brands--if a particular oil works well for you, use it. If you have had problems with an oil in the past, don't use it.

Brand	Properties
	VI	PP	FP	CCV	%ASH	HT/HS	TBN	4-Ball(1)
79 Guardol QLT 15W-40	137	-38	240*	3000*	1.3	4.4*	10.1	n/a
Chevron DELO 400 15W-40	134	-39*	230	3150	1.34	n/a(2)	11.3	0.599
Mobil Delvac 1300 Super 15W-40	150*	-36	215	4000(3)	1.5	4.4*	12*	n/a
Motorcraft Super Duty 15W-40	135	-30	232	3000*	0.9*	n/a(2)	8	n/a
Penzoil Long-Life 15W-40	145	-39*	218	3500	1.4	4.3	11	n/a
Shell Rotella T 15W-40	146	-24	213	n/a(2)	1.35	n/a(2)	10.2	0.683
Valvoline
All-Fleet Plus 15W-40	136	-37	215	3200	1.35	4.2	10.	n/a
Premium Blue 15W-40	139	-30	204	3100	1.35	4.2	10.3	0.707
Synthetics
Amsoil
Heavy Duty Diesel Marine 15W40	178	-44	230	2120*	0.5*(2)	4.1*	12*	0.35*(4)
Series 3000 Heavy Duty Diesel 5W-30	183*	-51*	230	2566(3)	0.5*(2)	3.5	12*	0.39
Mobil Delvac 1 5W-40	n/a(2)	-54	240*	3200(3)	1.3	n/a(2)	11	n/a

Best property ratings are indicated by asterisk (*)

(1) Four Ball Wear test results courtesy of Amsoil, from independent testing. Not all oils listed were tested.

(2) Information was not included in manufacturer's product information sheet. Amsoil ash information from
More Than You Ever Wanted to Know About Motor Oil by Ed Hackett.

VI: Viscosity Index--Rate of change in viscosity over a given temperature range (ASTM D-2270). Larger number indicates lesser change.

PP: Pour Point--Fluidity at low temperatures in degrees Centigrade (ASTM D-97). The lower the number, the colder it will flow. -24°C=-11°F; -51°C=-60°F

FP: Flash Point--Temperature at which the oil starts to vaporize in degrees Centigrade (ASTM D-92). Typically, the PowerStroke operates at 85-110°C, but can excede 120°C. 204°C=400°F

CCV: Cold Cranking (apparent) Viscosity--Resisance at -15°C (ASTM D-2602). Lower numbers indicate easier cold starting. (3)Delvac 1300 tested at -20°C; Series 3000 and Delvac 1 tested at -25°C.

%ASH: Percentage of sulfated ash--Residue remaining after the oil is burned. The lower the number the better.

HT/HS: High Temperature/High Shear Viscosity--Measure of protection under high temperatures (ASTM D-4683). Higher numbers indicate better protection.

TBN: Total Base Number (Detergent Alkalinity)--Indicates stability, engine protection and cleanliness, and performance. Higher numbers are better

4-Ball: Four Ball Wear Scar--Measurement of wear on a spinning bearing under load and at temperature (ASTM d-4172). Lower numbers indicate less wear. Tested at 1800 RPM/40 kg pressure/150°C for one hour. Scar diameter in millimeters. (4)Heavy Duty 15W-40 tested at 1200 RPM/40 kg/75°C.

Charles David Ledger; dieselmann©1999

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1999