Here's my compendium of part number crosses for the A3.
Item OEM Mfg OEM P/N Commercial Mfg Comm'l P/N
Air Dryer Dessicant Kit Haldex DQ6026 Midland Brake MBI DQ6026
Primary Fuel CAT 7E9763 Napa FIL 3239 Fram P1120
Engine Oil CAT 1R-0739 Napa FIL 1791
1R-1807 FIL 1791XE
FIL 1791 XD
FIL 7791
Fram PH8842 PH8842FP
TPH8842FP
PH49A
HPH49A
HPH49AFP
Transmission, External Allison 12356825 Napa 1268 AC PF897
Fram PH3519A
PF141
Napa 1553 Fram HP1
Napa 1551 Purolator PER20
Transmission, Internal Allison 29506392
Baldwin 19992
29540976
Napa ATP14959
Trans Oil 21qt capacity, 10 refill w/filter Dexron III, C-4, MIL-L-46167
Napa Premium Performance ATF Dexron III
Napa NHF 85-405 Premium Heavy Duty Tractor Hydraulic & Transmission Fluid GL-4
Engine Oil 21qt capacity, 19 refill w/filter, 18 refill w/o filter CAT ECF-3, API CJ-4 15W-40
Rotella T6 5W-40 Synth
T5 10W-40 Synth Blend
T Triple 15W-40
Delo Delo 400 Multigrade SAE 15W-40
Engine Coolant 27qt Capacity Antifreeze, Ethylene Glycol Federal Spec O-A-548, Type II 50/50 mix
Brake Fluid 2qt reservoir capacity BFS, Mil-B-46176 (Silicone) DOT-5 (Silicone) Napa DOT5 Silicone brake fluid 45-101
Transfer Case 7qt GO 80/90 MIL-L-2105 SAE J2360, API MT-1, API GL-5
80W/90 Gear Oil
Front/Rear Differentials 6qt GO 80/90 MIL-L-2105 SAE J2360, API MT-1, API GL-5
80W/90 Gear Oil
Steering Gearbox 3.13pt GO 80/90 MIL-L-2105 SAE J2360, API MT-1, API GL-5
80W/90 Gear Oil
Grease MIL-G-10924 NLGI #2 Lucas Red Tacky, X-tra Heavy Duty
Front shock
Monroe 34787
Water Pump Belt CAT 7E0744
Napa NBH 259345HD
NBH 259345
PBH17345
Fan Belt CAT 7PK1639.6
12448759