Gear oil formulation designed to meet bio-preferred criteria as well as give high performance

Figures & data

Table 1 The additives and fluids formulated with the TP-SO and the commercially available gear oils used in this study.

Abbreviation	Primary structure/active group	Trade name
Synthetic base oils
P-40	Poly alpha olefin	PAO 40
P-8	Poly alpha olefin	PAO 8
E-51	Ditridecyl adipate	Esterex A51
E-81	Ditridecyl phthalate	Esterex P81
E-101	Tri-isooctyl trimellitate	Esterex TM 101
Antioxidant/anti-wear additives
N-531	3,5 Di-t-butyl-4-hydroxy-hydrocinnamic acid,  C7–C9 alkyl ester	Naugalube 531
N-640	Butylated–octylated diphenylamine	Naugalube 640
N-438	Dimethyl diphenylamine	Naugalube 438
N-A	Alkylated phenyl-alpha-napthylamine	Naugalube APAN
22M	2,2′-Methylenebis(6-tert-butyl-4-methylphenol)	Lowinox 22M46
V-EZ	Zinc diamyldithiocarbamate and diamyl  ammonium diamyldithiocarbamate	Vanlube EZ
V-887	Tolutriazole compound in ester	Vanlube 887E
V-81	Dioctyldiphenylamine	Vanlube 81
V-996E	Methylene bis(di-butyl-dithiocarbamate)  and tolutriazole derivative	Vanlube 996E
V-73	Metal dialkyldithiocarbamate	Vanlube 73 Super Plus
ZDDP	Zinc dialkyl dithiophosphate	ZDDP
Pour point depressants
L-02	Proprietary	LZ3702
L-70	Proprietary	LZ7670
L-71	Proprietary	LZ7671A
Commercial gear oils
Com1	Proprietary	SAE 80 W-90 GL-5 Multi-Purpose Gear Lubricant
Com 2	Proprietary	CRC SL2472 API/GL-5 Plus New Generation Limited Slip Gear Oil
Com 3	Proprietary	LS 75 W-90 Synthetic Gear Lube
Com 4	Proprietary	75W90 Synthetic Gear Oil
Com 5	Proprietary	75W140 Synthetic Gear Oil

Figure 1 The measured pour point of TP-SO showing the reduction accomplished by the addition of a pour point depressant.

Figure 2 The measured pour point of TP-SO mixed with co-lubricant fluids.

Figure 3 The oxidation onset temperature of TP-SO with various additives.

Figure 4 The wear scar observed when testing TP-SO with added anti-wear additives in the four-ball wear test.

Table 2 The viscosity characteristics of the base oils and bio-based gear oil formulas from this work compared to those of commercial products.

Abbreviation	Kinematic viscosity at 40°C (mm^2/s)	Kinematic viscosity at 100°C (mm^2/s)	Viscosity index
Com 1	129.1	12.25	95
Com 2	141.19	12.19	96
Com 3	105.48	11.7	136
Com 4	119.94	14.51	156
Com 5	205.29	24.64	181
E-101	134.76	15.82	123
E-81	136.21	12.62	87
TP-SO	386.43	49.43	189
SBO	34.1	8.6	247
Bio-GO	262.6	32.21	165

Figure 5 The observed wear test results of the bio-based gear oil formulated here compared to those of commercial products.

Figure 6 The oxidation onset temperature of the bio-based gear oil formulated here compared to that of commercial products.