This document provides the technical basis for lubricant selection and controlled changeover in agricultural and forestry equipment. It is intended for engineering, maintenance and procurement teams responsible for mixed equipment fleets operating under variable and seasonal conditions.
Equipment covered
- Tractors and harvesters
- Forestry machinery and attachments
- Telehandlers and loaders
- Diesel powered auxiliary equipment
Key operating risks addressed
- Cold start operation following extended idle periods
- Wide ambient temperature variation
- High hydraulic load under intermittent duty cycles
- Contamination exposure from dirt, moisture and vibration
Hydraulic oil technical basis
Hydraulic systems used in agricultural and forestry equipment require stable viscosity performance across variable temperatures, defined antiwear protection and resistance to oxidation during intermittent operation. Oils meeting ISO 11158 L-HM and DIN 51524 Part 2 are commonly specified for these applications.
Hydraulic viscosity grade selection
| Operating condition | Typical viscosity grade | Selection rationale |
|---|---|---|
| Cold start operation and wide ambient variation | ISO VG 32 | Supports low temperature flow and responsive hydraulic system operation |
| General agricultural and forestry duty | ISO VG 46 | Provides balanced wear protection, thermal stability and consistent control |
Engine oil technical basis
Diesel engines used in agricultural and forestry equipment commonly specify mid SAPS heavy duty engine oils aligned with ACEA E9 performance categories. These oils are designed to support high load operation, extended service intervals and compatibility with modern emissions control systems.
Engine oil viscosity selection
| Operating focus | Typical viscosity grade | Selection rationale |
|---|---|---|
| General mixed duty and seasonal operation | 15W40 | Provides stable protection across wide temperature ranges and load conditions |
| Cold start performance or efficiency focus | 10W30 | Improves low temperature cranking and reduces internal friction |
Equivalency and approval position
Lubricants meeting ISO 11158 L-HM or DIN 51524 Part 2 for hydraulic systems, and ACEA E9 for diesel engines, are technically suitable for agricultural and forestry equipment when viscosity grades are selected in accordance with OEM requirements and operating conditions.
Changeover guidance
- Changeover should be completed during scheduled maintenance or seasonal servicing
- System flushing is not normally required when replacing oils of the same specification category
- Filters should be replaced in line with standard service practice