Choosing between ISO 46 and ISO 68 hydraulic oil comes down to three factors:
- your operating temperature
- the workload your equipment handles; and
- the age of your machine.
Before diving in, it’s worth understanding why you should search by ISO grade rather than a general SAE weight like “SAE 20.” ISO is the international standard for industrial lubricants and refers to a precise kinematic viscosity measured at 40°C.
SAE grades are broader ranges built around engine oils, and the two systems don’t translate cleanly.
The core difference between ISO 46 and ISO 68 is thickness. ISO 46 is the thinner of the two, which makes it better suited for colder climates, lighter equipment, and faster-moving systems where flow resistance matters.
ISO 68 is heavier, holds its lubricating film better under high heat, and handles the constant pressure demands of heavy machinery like excavators and forklifts.
Older machines with internal wear also tend to benefit from ISO 68, since the added thickness helps compensate for gaps in worn components.
ISO 46 Hydraulic Oils
These ISO 46 options cover synthetic-technology, fully synthetic, conventional mineral, and food-grade formulations for different operating environments and budgets.
Mobil DTE 10 Excel 46
Mobil DTE 10 Excel 46
Mobil DTE 10 Excel 46 is for high-pressure systems where deposit formation, wide temperature swings, or close-tolerance components are a concern. Also available in 68 grade.
Quick Specs
- Viscosity: 45.7 mm²/s @ 40°C
- Viscosity Index: 163
- Pour Point: -45°C
- Shear Stability Loss: 8%
Mobil DTE 10 Excel’s standout feature is the zinc-free anti-wear system combined with a high viscosity index. Most anti-wear hydraulic oils rely on ZDDP (zinc) for protection, which creates ash deposits in high-pressure systems. Mobil DTE 10 Excel provides wear protection without that buildup.
This is critical for tight-tolerance servo valves and CNC machines where internal deposits cause valve malfunction.
This hydraulic fluid is for operators of CNC equipment, plastic injection molding systems, or mobile hydraulics where cold starts and sustained heat are both present. If deposit-related valve failures have been an issue, the keep-clean chemistry addresses that directly.
Also approved for:
- Denison HF-0, HF-1, HF-2
- Bosch Rexroth 90245
- Eaton E-FDGN-TB002-E
- Husky injection molding systems
- Krauss-Maffei hydraulic systems
Mobil SHC 625
SHC 625 ISO VG 46 Synthetic Circulating and Gear Oil
Mobil SHC 625 fully synthetic ISO 46 gear and bearing oil engineered for extreme temperature performance and efficiency gains in heavy-duty industrial applications. U
Unlike Mobil DTE 10 Excel, which is built for hydraulic systems with synthetic-technology base oils, SHC 625 uses fully synthetic base stocks with a low traction coefficient optimized specifically for reducing friction in gears and rolling bearings.
Quick Specs:
- Viscosity: 46 mm²/s @ 40°C
- Viscosity Index: 161
- Pour Point: -54°C
- Flash Point: 225°C
SHC 625’s low traction coefficient reduces fluid friction in non-conforming surfaces like gears and rolling bearings. This lowers operating temperatures and can improve gear efficiency by up to 3.6% versus mineral oils.
SHC 65 is for operators of filled-for-life gearboxes, remotely located equipment where oil changes are costly, or mixer bearings and plastic calenders where sustained high temperatures are normal. The high VI makes it suitable for wide temperature swings without seasonal fluid changes.
Also approved for:
- SEW-Eurodrive
- AGMA 9005-F16
ISO 68 Hydraulic Oils
These ISO 68 alternatives range from synthetic-technology to conventional mineral and food-grade formulations, each suited to different heat loads and system requirements.
Mobil DTE 10 Excel 68
Mobil DTE Excel 68
Mobil DTE 10 Excel 68 is a synthetic-technology ISO 68 hydraulic oil designed for high-pressure systems operating in hot climates or under sustained heavy loads. Unlike gear oils that prioritize low traction coefficients, DTE 10 Excel uses synthetic-technology base oils with a zinc-free anti-wear system specifically formulated to protect hydraulic pumps and prevent deposit formation in tight-tolerance servo valves.
Quick Specs:
- Viscosity: 66.9 mm²/s @ 40°C
- Viscosity Index: 155
- Pour Point: -42°C
- Flash Point: 260°C
DTE 10 Excel 68’s zinc-free anti-wear package protects gear, vane, and piston pumps without creating the ash deposits that can jam servo valves in CNC machines and plastic injection molding systems.
DTE 10 Excel 68 is for operators of mobile hydraulics working in hot climates (above 30°C), heavy construction equipment under constant pressure, or older systems with internal wear where the thicker viscosity helps maintain system pressure and reduce internal leakage.
Also approved for:
- Denison HF-0, HF-1, HF-2
- Bosch Rexroth 90245
- Eaton E-FDGN-TB002-E
D-A PresurFlo 68
Presurflo Hydraulic Fluid ISO 68
D-A PresurFlo 68 is a conventional mineral-based ISO 68 anti-wear hydraulic oil designed for high-pressure systems in construction equipment and stationary industrial installations.
This is a straightforward AW oil with zinc-based anti-wear additives that also doubles as an R&O oil for industrial gearboxes.
Quick Specs:
- Viscosity: 68 mm²/s @ 40°C
- Viscosity Index: 100
- Pour Point: -25°C
- Flash Point: 232°C
PresurFlo 68’s anti-wear package provides protection for steel, brass, and bronze pump components in both vane and piston pumps operating at maximum pressure ratings.
The VI of 100 is typical for mineral-based oils, which makes it suitable for moderate temperature ranges but less capable than synthetic options in extreme cold or sustained heat. The demulsibility feature helps water separate out rather than emulsify, which protects the system in wet service environments.
PresurFlo 68 is for operators looking for a cost-effective AW hydraulic oil that meets standard OEM specifications without the premium pricing of synthetic or synthetic-technology fluids. It works in both mobile and stationary hydraulics and can pull double duty in industrial gearboxes requiring R&O oil, which reduces inventory complexity.
Also approved for:
- Eaton Vickers HF-0, HF-1, HF-2
- Cincinnati Machine P-69
- Bosch Rexroth RD 90220
- ISO 11158 HM
- DIN 51524 parts 1, 2, 3
Petrochem FoodSafe FMO 68
Petrochem Synthetic Hydraulic Oil, Food Grade, ISO 68
Petrochem FoodSafe FMO 68 is an NSF H1-registered ISO 68 anti-wear hydraulic oil formulated with pure white oil base stocks for use in food processing, pharmaceutical, and personal care facilities.
Unlike conventional mineral-based hydraulic oils, this is designed for environments where incidental food contact is a possibility.
Quick Specs:
- Viscosity: 68 mm²/s @ 40°C
- Viscosity Index: 110
- Pour Point: -9°C
- Flash Point: 210°C
- NSF H1 Registration: 147438
FoodSafe FMO 68 can be used in hydraulic systems, enclosed gearboxes, chains, and bearings where a leak or overspray could come into contact with food products. The VI of 110 sits between conventional mineral oils and synthetic options, providing reasonable temperature stability without the premium cost.
FoodSafe FMO 68 is for operators of food processing equipment where regulatory compliance requires NSF H1-registered lubricants. It allows for inventory consolidation since it can replace non-food-grade hydraulics in facilities transitioning to all-food-safe lubricants.
Applications include:
- Hydraulic systems in food processing plants
- Pneumatic lubricators and light-duty air compressors
- Enclosed gearboxes, chains, and bearings
- Vacuum pumps and blowers
- Angelus seamers (Manzel lubricators)
Important Considerations for Hydraulic Oils
ISO VG stands for International Organization for Standardization Viscosity Grade, and the number (32, 46, 68) represents the oil’s kinematic viscosity measured at exactly 40°C. Whether a label reads “ISO 46,” “ISO VG 46,” or “VG 46,” these all refer to the same thing, and the higher the number, the thicker the oil.
Do not use motor oil as substitute for hydraulic oil
Using SAE motor oil as a substitute to hydraulic fluid is NOT a safe workaround. Motor oils contain detergents designed to keep engines clean, but in a hydraulic system those same detergents cause the oil to hold water in suspension rather than letting it separate.
That leads to corrosion, cavitation, and degraded lubrication. Standard hydraulic oils are formulated to shed water, not absorb it.
AW and ISO are not the same thing
When you see a label that reads “AW 46” or “AW ISO 46,” you’re looking at two separate pieces of information combined into one product name. ISO tells you how thick the oil is. AW tells you what’s in it.
ISO, as covered earlier, refers to the oil’s kinematic viscosity at 40°C. The number indicates thickness: the higher the number, the heavier the oil. AW stands for Anti-Wear, and it describes an additive package, typically containing ZDDP (zinc dialkyldithiophosphate), that forms a protective layer on metal surfaces under high pressure.
Most modern hydraulic oils are AW-formulated, but not every ISO-rated industrial oil is. Some systems, including certain air compressors and older machinery, call specifically for R&O oil, which stands for Rust and Oxidation inhibited, and does not carry the heavy anti-wear additives found in AW hydraulic fluid. Using an AW formula in a system designed for R&O oil is not a safe upgrade. It is a mismatch.
An AW Formula can damage the wrong system
The risk is chemical incompatibility, particularly when an AW oil enters a system that already contains a different additive package.
When two incompatible oils meet, their additive chemistries can react. The result is what engineers call an additive clash: gelatinous deposits, colloidal solids, or flocculent precipitation forming inside the system. These deposits move through the circuit and clog filters fast. In documented cases, a 5-micron filter lost more than 60% of its service life after an incompatible fluid was introduced. The deposits also adhere to valve cores and jam them.
Moreover, incompatible additive packages can generate acids that corrode internal components. You may also see oil temperatures spike unexpectedly and pressure gauges fluctuate erratically, both signs that the system is working against compromised fluid.
A note about multi-viscosity fluids
MV 46 stands for Multi-Viscosity ISO 46. It meets the same ISO 46 viscosity standard at operating temperature, but behaves differently at the extremes.
Standard ISO 46 is a monograde oil: reliable within a normal temperature range, but prone to thickening in the cold and thinning out when the machine runs hot. MV 46 contains viscosity index improvers that counteract both problems, keeping the oil fluid enough for cold starts and thick enough to protect the pump under sustained heat.
Closing Note
Choosing between ISO 46 and ISO 68 is straightforward when you know your operating temperature and equipment age. The real danger comes from overlooking what else the oil needs to do.
If your hydraulic system shares a reservoir with wet brakes or clutches, particularly in agricultural or construction equipment, standard hydraulic oil is not enough.
These components require specialized UTTO (Universal Tractor Transmission Oil) formulations with friction modifiers that prevent brake disintegration. Standard hydraulic oils also shed water by design, allowing it to settle and drain.
Using engine oil as a substitute emulsifies water instead, keeping it suspended and accelerating corrosion. Always verify your owner’s manual for specific requirements.
