HLP oil
Mobil DTE 20 Ultra
For precision industrial hydraulics.
- For pumps, servo valves and NC machines exposed to deposits, with controlled water separation.
- Match the machine’s requirements.
Oil selection tool
Guide · hydraulic oils
Which hydraulic oil? HLP, HVLP and ISO VG viscosity
Choose hydraulic oil by class, ISO VG viscosity and machine requirements. Compare specifications and applications across Mobil oils.
In short
Start with the manual: note the oil class and required viscosity. Your chosen hydraulic oil must meet the machine’s requirements. HLP is used in typical industrial hydraulic applications. For cold starts and hot running conditions, consider a high-viscosity-index HVLP oil.
- Sample analysis helps inform oil changes.
- Assess the results alongside the manufacturer’s recommendations.
- Compare selected series in the Mobil hydraulic oil range.
01Oil classifications
Understanding HL, HLP and HVLP
Letters describe the oil class; the VG number describes viscosity. Mobil data sheets give DIN 51524 and ISO 11158 classifications to compare with the manual.
Do not replace HLP with HL without the machine manufacturer’s approval.
Reading the designation
HLP 46
Combines an oil class with a viscosity grade. Similar numbers do not make oils interchangeable.
| Classification | Standard | Application scope | Mobil example |
|---|---|---|---|
| HL | DIN 51524-1 | Hydrostatically driven systems under thermal stress and at risk of corrosion, for example from water | — |
| HLP | DIN 51524-2 | As for HL, plus hydraulic pumps and motors requiring anti-wear protection under mixed-friction conditions | DTE 20 Ultra, Nuto H, DTE 10 Excel |
| HVLP | DIN 51524-3 | As for HLP; Mobil data sheets assign this class to high-viscosity-index oils | Univis N, selected DTE 10 Excel grades |
| L-HM / L-HV | ISO 11158 | International classifications listed alongside the corresponding DIN classes | DTE 20 Ultra: L-HM; Univis N: L-HV |
02ISO VG viscosity
How to read ISO VG viscosity
ISO VG indicates nominal kinematic viscosity at 40°C, in mm²/s. A higher number means greater flow resistance; suitability depends on the machine requirements.
Choose grade 32, 46 or 68 according to the pump manual. Also consider VI: a higher index means greater viscosity stability as temperature changes.
| Product, VG 46 grade | Nuto H | DTE 25 Ultra | Univis N | DTE 10 Excel |
|---|---|---|---|---|
| Data sheet VI | 98 | 110 | 152 | 163 |
Within the same grade, a higher-VI oil retains better cold flow and greater viscosity when hot.
Hydraulic oil selection, step by step
Start with the manual, current product and operating conditions.
Read the requirements
Check the machine or pump manual. Note the class, grade and specification before comparing hydraulic oils.
Identify the current product
Copy the full name from the drum or product data sheet. A label photograph helps distinguish similarly named series.
Describe operating temperatures
A machine may start cold and its hydraulic system run hot. Check whether the manual permits HVLP across that temperature range.
Identify special requirements
Note servo valves, water exposure or leakage risks.
Plan the oil change
Check product compatibility before switching series. Ask whether the system needs flushing.
Compare Mobil hydraulic oils
Compare machine requirements with each series’ applications. The cards show viscosity variants and current shop offers.
- All Mobil hydraulic oils
- Which one to choose? Ask an expert
HVLP oil
Mobil Univis N
For changing operating temperatures.
- High-VI oil for cold starts and hot operation, including damp conditions.
- Applications include industrial, mobile and marine equipment.
Zinc-free oil
Mobil DTE 10 Excel
For demanding hydraulic systems.
- Zinc-free, high-VI oil for high pressures and temperatures, including CNC servo valves.
- Supports cleanliness, efficiency and anti-wear protection.
Avoid hydraulic oil selection mistakes
Check compatibility with the machine, operating temperatures and contamination. These five mistakes can undermine selection and condition assessment.
Mistake
Topping up by grade number alone
Instead:
Check the oil class and compatibility before mixing.
Mistake
Increasing viscosity instead of diagnosing
Instead:
The manual remains the reference.
Mistake
Choosing on price alone
Instead:
Compare VI and temperature requirements too.
Mistake
Relying on the calendar alone
Instead:
Follow the manufacturer’s recommendations and monitor oil condition through testing.
Mistake
Overlooking contamination
Instead:
Include water and solid particles in your assessment of the hydraulic system.
Have a similar case?
When to change hydraulic oil
Base oil changes on oil condition and the machine manufacturer’s recommendations. Sampling every 3 months or 500 operating hours is a starting point, not a drain interval.
A good result does not automatically extend the drain interval. Analysis includes:
- Viscosity and oxidation or total acid number (TAN)
- Water, particles and wear metals
- Cleanliness by ISO 4406 code
Check your selection with an expert
Provide the machine model, pump type and current oil. Our specialist will compare the requirements and reply with a specific product recommendation.
Jan Kowalski
Technical Engineer for Lubricants, Mobipol
“Tell me the machine, pump type and current oil. I will say whether HLP is enough or a high viscosity index oil is the better choice.”
Frequently asked questions
Do not top up with a different series without checking compatibility. Even similar classes and grades are not enough; ask an expert or the machine manufacturer before switching.
HLP suits typical industrial hydraulic applications that meet its requirements. For cold starts and hot operation, consider HVLP, such as Univis N; compare the classes in the table.
The HL standard covers thermal loading and corrosion risk. HLP also addresses anti-wear protection for hydraulic pumps and motors operating under mixed-friction conditions. The manufacturer specifies the required class.
It identifies class L-HV under ISO 11158 and viscosity grade VG 46. The Univis N data sheet lists L-HV alongside DIN 51524-3.
Follow the manufacturer’s recommendations and monitor oil condition through testing. Sampling every 3 months or 500 hours is a starting point for analysis, not a universal oil-change interval.
Appearance and smell are not enough for a diagnosis. Analysis checks water, particles, metals and changes in oil properties; assess the result alongside the equipment’s history.
Check the machine’s hydraulic system requirements; Univis N also covers mobile applications. UTTO transmission-hydraulic oils for tractors and agricultural machinery require separate selection.
