Correlation Study of Physicochemical, Rheological, and Tribological Parameters of Engine Oils

Table 7

Correlation coefficient matrix for lubricant properties (physicochemical and tribological).

	@ 15°C; g-cm^−3	@ 40°C	@ 100°C	VI	TAN	TBN	Sulphated; ash	Zn	Mo	P	COF	WSD
@ 15°C g-cm^−3	1	0.83	0.73	0.73	0.08	0.59	−0.68	0.08	0.92	0.01	0.41	0.75
@ 40°C	0.83	1	.91	0.90	−0.53	0.91	−0.50	−0.15	0.95	0.22	0.73	0.78
@ 100°C	0.73	.91	1	0.76	−0.34	0.85	−0.46	0.02	0.88	−0.04	0.68	0.81
VI	−0.73	−0.90	−0.76	1	0.71	0.94	0.13	0.53	−0.83	0.60	−0.92	−0.97
TAN	−0.08	−0.53	−0.34	0.71	1	0.70	0.33	0.96	−0.20	0.98	−0.84	−0.55
TBN	−0.59	−0.91	−0.85	0.94	0.70	1	0.08	0.50	−0.76	0.56	−0.92	−0.91
Sulphated; Ash	−0.68	−0.50	−0.46	0.13	0.33	0.08	1	0.51	−0.46	−0.47	−0.31	−0.45
Zn	0.08	−0.15	0.02	0.53	0.96	0.50	−0.51	1	0.03	0.99	−0.79	−0.42
Mo	0.92	0.95	0.88	0.83	0.20	0.76	−0.46	0.03	1	−0.04	0.55	0.88
P	0.01	−0.22	−0.04	0.60	0.98	0.56	−0.47	0.99	−0.04	1	−0.83	−0.49
COF	0.41	0.73	0.68	−0.84	−0.84	−0.92	−0.31	−0.79	0.55	−0.83	1	0.82
WSD	0.75	0.91	0.76	−0.97	−0.55	−0.91	−0.45	0.88	−0.35	0.65	0.82	1

Not relevant.