AW ISO 32, 46, and 68 Hydraulic Oil Compared
ISO VG 32, 46, and 68 are viscosity grades centered near 32, 46, and 68 cSt at 40°C. The number does not state quality. Select the grade that keeps the system within the pump and OEM operating-viscosity range at actual oil temperature.1
Quick comparison
| Grade | Nominal viscosity at 40°C | Relative behavior |
|---|---|---|
| ISO VG 32 | 32 cSt | Flows more readily |
| ISO VG 46 | 46 cSt | Intermediate |
| ISO VG 68 | 68 cSt | Higher viscosity |
A hotter climate may influence selection, but it does not automatically require ISO 68.
What does AW mean?
AW means antiwear. These oils commonly include additives for pump wear, oxidation, rust, corrosion, foam, and water separation. Confirm the exact DIN, ISO, Denison, Eaton/Vickers, Bosch Rexroth, or equipment requirement.
Which grade is used where?
Applications vary by machine. ISO 32 is often considered for colder or high-speed systems; ISO 46 is common in general industrial service; ISO 68 may suit hotter or slower systems. Those are tendencies, not recommendations.
Use reservoir temperature, not just ambient temperature.
Which Inforca products match the grades?
Inforca lists:2
- PureGuard XL AW ISO 32, PG801;
- PureGuard XL AW ISO 46, PG802;
- PureGuard XL AW ISO 68, PG803.
Supplied sheets describe zinc-based antiwear formulations and mention DIN 51524, ISO 11158 HL/HM, and Denison HF-0. The files do not include a complete properties table, approval status, or package matrix, so confirm the current TDS and availability.
Can these oils go in tractors?
Not when a common reservoir requires J20C or another multifunction tractor fluid unless the manufacturer explicitly permits AW oil. Wet brakes and clutches need friction performance not established by ISO VG.
PureGuard PG805 is the active tractor-hydraulic product for applications where its J20C positioning matches.
What data should be sent for selection?
Machine and pump model, manual specification, ISO grade, normal/minimum/maximum temperature, pressure, filter rating, current oil, contamination, capacity, monthly volume, and package size.
Frequently asked questions
Is ISO 68 better than ISO 46?
No. It is more viscous, not inherently higher quality.
Can ISO 32 and 46 be mixed?
Avoid deliberate mixing. It changes viscosity and may mix additive systems.
Does a leak mean use thicker oil?
No. Repair the leak and use the specified grade.
Can AW oil be used in a transmission?
Only if the equipment maker specifies it.
Does Florida require ISO 68?
No. Determine actual operating temperature and OEM limits.
Confirm the operating viscosity
Send Inforca the machine, pump, specification, temperatures, current oil, capacity, volume, and packaging. The team can compare PG801, PG802, and PG803 documentation.
Sources
Footnotes
-
Bosch Rexroth, General Hydraulic Fluid Specifications, accessed September 10, 2026. ↩
-
Inforca International, Products: Hydraulic Oils, accessed September 10, 2026. ↩
Related Inforca products
Check each product's data sheet against your exact specification before ordering.
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