Mobil DTE 26 Ultra Hydraulic Oil
ISO VG 68 Antiwear Hydraulic Oil for High-Pressure Industrial Systems
Mobil DTE 26 Ultra is a high-performance ISO VG 68 antiwear hydraulic oil designed for demanding industrial hydraulic systems using high-pressure, high-output pumps and precision hydraulic components.
Part of the Mobil DTE 20 Ultra Series, it provides wear protection, strong oxidation and thermal stability, deposit control, corrosion protection and controlled water separation. Its keep-clean performance is particularly useful in hydraulic systems with close-clearance servo and proportional valves where sludge or deposits can interfere with reliable operation.
Mobil DTE 26 Ultra is the ISO VG 68 grade in the series and is the current corresponding product for compatible applications that previously used Mobil DTE 26.
Key Benefits
- ISO VG 68 hydraulic oil
- High-performance antiwear formulation
- Designed for high-pressure and high-output hydraulic systems
- Helps protect hydraulic pumps and system components
- Outstanding keep-clean performance
- Helps reduce sludge and deposit formation
- Strong oxidation and thermal stability
- Enhanced corrosion protection
- Controlled demulsibility for water separation
- Suitable where small amounts of water may enter the hydraulic system
- Suitable for hydraulic systems containing gears and bearings
- Supports close-clearance servo and proportional valves
- Up to 2X longer oil drain intervals versus qualifying competitive hydraulic oils in Mobil testing
- Bosch Rexroth Fluid Rating List 90245 approved
- Denison HF-0, HF-1 and HF-2 approved
- Eaton E-FDGN-TB002-E approved
- Recommended for applications requiring Fives Cincinnati P-69
- Meets DIN 51524-2:2017-06
- Meets ISO L-HM under ISO 11158:2023
ISO VG 68 Hydraulic Oil
Mobil DTE 26 Ultra is classified as ISO VG 68.
- Kinematic viscosity at 40°C: 68.6 mm²/s
- Kinematic viscosity at 100°C: 8.9 mm²/s
- Viscosity Index: 104
ISO VG 68 should only be used where the equipment manufacturer specifies or permits that viscosity grade.
Antiwear Protection for Hydraulic Systems
Mobil DTE 26 Ultra is formulated to provide antiwear protection in demanding hydraulic systems.
Mobil specifically identifies the DTE 20 Ultra Series for systems requiring:
- High load-carrying capability
- Antiwear protection
- High-pressure operation
- High-output pumps
The current Mobil approval list includes major hydraulic-equipment requirements from Bosch Rexroth, Denison and Eaton.
Keep-Clean Performance
Modern hydraulic equipment can contain very small internal clearances.
Deposits, sludge and varnish can interfere with components such as:
- Servo valves
- Proportional valves
- Hydraulic pumps
- Control valves
- Precision hydraulic components
Mobil DTE 26 Ultra is formulated with keep-clean performance to help reduce deposits and sludge that can contribute to sticking, malfunction and maintenance requirements.
Oxidation and Thermal Stability
Heat and oxygen gradually degrade hydraulic oil during service.
Oxidation can contribute to:
- Sludge
- Varnish
- Deposits
- Oil thickening
- Filter restriction
- Reduced valve performance
Mobil DTE 26 Ultra is formulated for strong oxidation and thermal stability to help maintain hydraulic-system cleanliness during demanding operation.
Up to 2X Longer Oil Drain Intervals
Mobil states that DTE 20 Ultra Series oils have demonstrated up to two times longer oil drain intervals compared with similar competitive hydraulic oils.
The comparison is against qualifying hydraulic oils with approximately 100 viscosity index and antiwear performance meeting at least ISO 11158 L-HM and/or DIN 51524-2 HLP requirements.
Actual hydraulic-oil life depends on factors including:
- Operating temperature
- Contamination
- Water ingress
- Filtration
- Equipment design
- Duty cycle
- Maintenance practices
- OEM requirements
Used-oil analysis is recommended when establishing extended drain intervals.
Water Separation and Demulsibility
Water can enter hydraulic systems through condensation, seals, maintenance, process conditions or environmental exposure.
Mobil DTE 26 Ultra provides controlled demulsibility to help separate water from the hydraulic oil so it can be removed.
The current ISO VG 68 technical data lists 20 minutes to 3 mL emulsion at 54°C under ASTM D1401.
Mobil specifically includes hydraulic systems where small amounts of water are unavoidable among the intended applications for the DTE 20 Ultra Series.
Corrosion Protection
Current typical laboratory results include:
- ASTM D665 Procedure B Rust Test: Pass
- ASTM D130 Copper Strip Corrosion: 1A
These laboratory results characterize the oil's rust and copper-corrosion performance under standardized test conditions.
Load-Carrying Performance
Mobil identifies DTE 20 Ultra for hydraulic systems requiring high load-carrying capability.
For DTE 26 Ultra, the typical FZG Scuffing Fail Load Stage is 11.
Mobil also lists hydraulic systems containing gears and bearings among the intended applications for the DTE 20 Ultra Series. This does not make DTE 26 Ultra a general-purpose industrial gear oil.
Industrial Hydraulic Applications
Potential compatible applications include:
- CNC machinery
- Manufacturing equipment
- Hydraulic presses
- Industrial hydraulic power units
- Automated production machinery
- Process equipment
- Systems using proportional valves
- Systems using close-clearance servo valves
Always verify that the equipment requires ISO VG 68 and the relevant hydraulic-fluid specification.
Mobil DTE 26 Ultra vs. Mobil DTE 26
Mobil DTE 26 Ultra is the current ISO VG 68 product in the DTE 20 Ultra family.
Mobil identifies the older DTE 20 Series products as being replaced by corresponding DTE 20 Ultra viscosity grades.
Mobil DTE 26 Ultra corresponds to legacy Mobil DTE 26.
Current Approvals
- Bosch Rexroth Fluid Rating List 90245
- Denison HF-0
- Denison HF-1
- Denison HF-2
- Eaton E-FDGN-TB002-E
- HOCNF Norway-NEMS, Black
Recommended for Applications Requiring
Meets or Exceeds
- ASTM D6158 Class HMHP
- China GB 11118.1-2011 L-HM General
- China GB 11118.1-2011 L-HM High Pressure
- DIN 51524-2:2017-06
- ISO L-HM, ISO 11158:2023
Note: Mobil's current DTE 26 Ultra table does not list Husky approval, JCMAS HK VG68 or the older Vickers M-2950-S / I-286-S references.
Typical Technical Properties
| Property |
Typical Value |
| ISO Viscosity Grade |
68 |
| Density at 15.6°C |
0.8743 kg/L |
| Kinematic Viscosity at 40°C |
68.6 mm²/s |
| Kinematic Viscosity at 100°C |
8.9 mm²/s |
| Viscosity Index |
104 |
| Pour Point |
-30°C |
| Flash Point, COC |
252°C |
| FZG Scuffing Fail Load Stage |
11 |
| Copper Strip Corrosion |
1A |
| Rust Characteristics, Procedure B |
Pass |
| Emulsion, Time to 3 mL at 54°C |
20 min |
| Total Acid Number |
0.7 mg KOH/g |
| Foam Sequence I |
10/0 ml |
| Foam Sequence II |
20/0 ml |
| Foam Sequence III |
0/0 ml |
Typical properties represent normal production values and should not be treated as guaranteed batch specifications.
Frequently Asked Questions
What is Mobil DTE 26 Ultra?
Mobil DTE 26 Ultra is a high-performance ISO VG 68 antiwear hydraulic oil designed for demanding industrial hydraulic systems.
What viscosity is Mobil DTE 26 Ultra?
Mobil DTE 26 Ultra is ISO VG 68. Its typical kinematic viscosity is 68.6 mm²/s at 40°C and 8.9 mm²/s at 100°C.
Is Mobil DTE 26 Ultra the same as Mobil DTE 26?
Mobil DTE 26 Ultra is the current corresponding ISO VG 68 product in the DTE 20 Ultra family for applications that previously used legacy Mobil DTE 26.
Is Mobil DTE 26 Ultra an antiwear hydraulic oil?
Yes. Mobil classifies the DTE 20 Ultra Series as high-performance antiwear hydraulic oils.
Is Mobil DTE 26 Ultra suitable for high-pressure hydraulic systems?
Yes. The product is designed for hydraulic systems using high-pressure, high-output pumps.
Can Mobil DTE 26 Ultra be used in CNC machines?
The DTE 20 Ultra Series is intended for hydraulic systems with close-clearance servo valves and numerically controlled machine tools. The individual machine must require ISO VG 68 and compatible specifications.
Does Mobil DTE 26 Ultra help control hydraulic deposits?
Yes. Outstanding keep-clean performance and deposit control are central features of the DTE 20 Ultra Series.
Can Mobil DTE 26 Ultra extend hydraulic oil life?
Mobil reports up to two times longer oil drain intervals compared with qualifying competitive hydraulic oils under its stated testing conditions. Actual service life depends on equipment, contamination, temperature, filtration and operating conditions.
Is Mobil DTE 26 Ultra approved by Bosch Rexroth?
Yes. Mobil currently lists Bosch Rexroth Fluid Rating List 90245 among the approvals for DTE 26 Ultra.
Does Mobil DTE 26 Ultra have Denison approval?
Yes. Mobil lists Denison HF-0, HF-1 and HF-2 approvals.
Is Mobil DTE 26 Ultra approved by Eaton?
Yes. Eaton E-FDGN-TB002-E is listed as a current approval.
Does Mobil DTE 26 Ultra meet Cincinnati P-69?
Mobil recommends DTE 26 Ultra for applications requiring Fives Cincinnati P-69.
Is Cincinnati P-69 an approval for DTE 26 Ultra?
Mobil places Fives Cincinnati P-69 under its recommended-for-use category rather than its formal approvals section.
Does Mobil DTE 26 Ultra meet DIN 51524-2?
Yes. Mobil currently lists DIN 51524-2:2017-06 among the requirements met or exceeded.
Does Mobil DTE 26 Ultra meet ISO 11158?
Yes. Current Mobil information lists ISO L-HM under ISO 11158:2023.
Does Mobil DTE 26 Ultra have Husky approval?
No current Mobil DTE 26 Ultra approval table lists Husky for the ISO VG 68 grade. Husky is listed for Mobil DTE 25 Ultra, the ISO VG 46 grade.
Does Mobil DTE 26 Ultra meet Vickers M-2950-S or I-286-S?
Those older Vickers references are not included in Mobil's current DTE 26 Ultra specification and approval table. They should not be presented as current DTE 26 Ultra specifications without separate current documentation.
What is the pour point of Mobil DTE 26 Ultra?
The typical pour point is -30°C.
What is the flash point of Mobil DTE 26 Ultra?
The typical Cleveland Open Cup flash point is 252°C.
What is the viscosity index of Mobil DTE 26 Ultra?
The typical viscosity index is 104.
How does Mobil DTE 26 Ultra handle water?
The fluid uses controlled demulsibility to help separate water from the oil. Mobil includes hydraulic systems where small amounts of water are unavoidable among its intended applications.
Can Mobil DTE 26 Ultra be used in systems containing gears and bearings?
Yes. Mobil specifically lists hydraulic systems containing gears and bearings among DTE 20 Ultra applications.
Is Mobil DTE 26 Ultra a gear oil?
No. It is an ISO VG 68 antiwear hydraulic oil. Its suitability for hydraulic systems containing gears does not make it a replacement for dedicated industrial gear oil.
Can Mobil DTE 26 Ultra be used instead of ISO 46 hydraulic oil?
Only when the equipment manufacturer permits ISO VG 68. ISO VG 46 and ISO VG 68 are different viscosity grades and should not be substituted solely because both are hydraulic oils.
How often should Mobil DTE 26 Ultra be changed?
Follow the equipment manufacturer's recommendations and consider oil-condition monitoring when establishing extended drain intervals. Mobil's up-to-2X oil-life result is comparative test performance rather than a universal oil-change schedule.
