Understanding Hydraulic Oils – HLP 32, HLP 46 & HVLP Compared
Hydraulic oils transmit power, lubricate components, and protect against wear. But what are the differences between HLP 32, HLP 46, and HVLP? Here is a clear overview with practical tips for choosing the right oil.
Thinner & better for cold conditions
With a viscosity of 32 mm²/s at 40°C, HLP 32 is more fluid. Ideal for winter operation, as it remains flowable at lower temperatures.
Thicker & more durable
With 46 mm²/s at 40°C, HLP 46 is more viscous. It provides a more stable lubrication film under high temperatures and continuous load – ideal for summer use.
Which oil should you choose?
The choice depends on temperature range and manufacturer specifications:
- HLP 32: better for cold conditions & winter use.
- HLP 46: suitable for warm temperatures & continuous operation.
HLP
Standard hydraulic oil with additives against wear and corrosion.
HVLP
Stable across large temperature variations. Thin in cold, stable in heat.
HVLP 46
A universal solution for year-round use. Slightly more expensive but versatile.
HVLP downside
Slightly higher energy consumption and cost compared to standard HLP oils.
| Category | Properties | Application |
|---|---|---|
| H | Base oils without additives | Rarely used today |
| HL | Oxidation & corrosion protection | Up to approx. 200 bar |
| HLP | High-pressure additives, wear-resistant | Up to and above 200 bar |
| HVLP | Like HLP + temperature stability | For varying temperatures |
| HLPD | With cleaning additives | Special applications, region-specific |
Important: Always follow manufacturer approvals and machine manuals.
Can I mix HLP 32 and HLP 46?
Not recommended. Different viscosities can affect performance. It is better to switch to one type according to manufacturer specifications.
When is HVLP worth it?
Especially if your machine is used year-round or exposed to extreme temperature variations.
What does the number in HLP/HVLP mean?
The number indicates the kinematic viscosity at 40°C in mm²/s. Higher values mean thicker oil.
