The Hydraulic Efficiency Gap: Why Replacing the Engine Is Only Half the Battle

The mobile machinery industry is in the middle of a structural power transition.

Driven by electrification targets, emissions regulation, and the rapid shift toward E-Mobility, OEMs are investing heavily in:

• diesel-to-electric drivetrain replacement

• battery-electric machine platforms

• electrified working hydraulics

On paper, this looks like a complete transformation.

But in reality, one fundamental question remains unresolved:

Are we improving system efficiency — or just relocating the losses?

At DMCA Solutions, we track how architecture decisions in hydraulics and electrification directly impact sourcing strategy, supplier selection, and system-level risk.

And one pattern is increasingly clear:

The powertrain is changing faster than the system it drives.

1. The efficiency illusion: replacing the engine is not enough

The logic behind electrification is compelling:

• diesel engines: ~30–40% efficiency

• electric drives: often >90% efficiency in optimal range

So the assumption is:

remove combustion → solve efficiency

But this only addresses one layer of the system.

The hydraulic circuit — which actually performs the work — remains largely unchanged in many machine architectures.

And this is where the real losses persist.

Because:

improving the energy source does not automatically improve the energy consumption mechanism. Powertrain efficiency and hydraulic efficiency are separate problems.

2. The hidden cost: throttling losses inside the system

One of the largest but least visible inefficiencies in mobile machinery is throttling loss.

In traditional constant-flow hydraulic systems:

• the pump delivers maximum flow continuously

• excess flow is throttled through valves

• energy is dissipated as heat regardless of demand

This means:

the system consumes energy even when it is not doing useful work

Losses are not caused by components alone.

They are driven by operating logic.

Which leads to a critical insight:

efficiency is not only a hardware problem — it is an architecture problem

3. Flow-on-Demand: efficiency through operating strategy

The shift toward Flow-on-Demand control fundamentally changes this equation.

Instead of fixed supply:

• pump output matches actual demand

• excess flow is eliminated at source

• throttling losses are reduced structurally

Efficiency improvements are not marginal. In representative machine categories such as telehandlers and wheel loaders, system-level energy consumption can drop dramatically compared to constant-flow architectures.

The key point is not the exact percentage. It is the direction:

operating strategy is becoming as important as component selection

4. Electric drive enables a new control dimension

Electrification introduces a capability that diesel systems cannot naturally provide:

continuous, efficient motor speed variation.

This enables:

• real-time adaptation of pump speed to hydraulic demand

• operation in optimal efficiency zones

• reduced reliance on throttling-based control

In other words:

speed becomes a control variable, not just an output consequence

This unlocks a new generation of system behavior:

• smoother energy profiles

• lower peak losses

• improved controllability across load cycles

For OEMs, this shifts design complexity upward:

from component engineering → to system control architecture

5. Noise: the hidden system architecture indicator

As diesel engines disappear, another effect emerges:

hydraulic noise becomes fully exposed

Previously masked by combustion engines, system acoustics now matter more than ever.

Noise is no longer a comfort feature. It is a system design output.

Hydraulic noise comes from:

• airborne radiation

• structure-borne transmission

• fluid-borne pressure pulsations

And critically:

noise is strongly influenced by operating strategy, not only component design

Lower-speed, demand-matched operation reduces:

• vibration intensity

• pressure pulsation amplitude

• perceived acoustic output

Which means:

acoustics are becoming an architectural KPI, not an add-on feature

6. Complexity is the new constraint

As systems evolve, functionality increases:

• electrified hydraulics

• multi-pump architectures

• autonomous machine functions

• integrated safety and control systems

At the same time:

• engineering resources are tightening

• software complexity is increasing

• cyber security requirements are emerging

A structural reality is forming:

system complexity is increasing faster than engineering capacity

This creates a sourcing implication:

capability is no longer just about components — it is about integration burden

7. Cybersecurity enters the hydraulic system

As hydraulics become digitally controlled, connected, and software-defined:

cyber security becomes part of the hydraulic architecture

Not as IT, but as system engineering.

Risks include:

• CAN communication vulnerabilities

• ECU-level access exposure

• remote diagnostics attack surfaces

• functional safety interdependencies

This introduces a new sourcing dimension:

suppliers are no longer just component providers — they are system security contributors

8. Subsystems: the shift from engineering to integration

The emerging response is subsystem-based architecture:

Instead of building systems from scratch, OEMs increasingly integrate:

• pre-engineered hydraulic modules

• embedded control logic

• validated safety and communication layers

• plug-and-play functional units

This changes the development model:

From:

full custom engineering per machine

To:

subsystem integration with defined interfaces

The impact is significant:

• faster development cycles

• lower integration risk

• reduced engineering load

• improved validation consistency

In sourcing terms:

the question is shifting from components to architectures

9. Industry signals: what OEM priorities reveal

Across industry discussions, the focus is shifting toward:

• energy efficiency

• noise reduction

• functional safety

• system-level architecture

• autonomous capability integration

Not isolated component performance.

But system behavior.

This confirms a structural shift:

innovation is no longer component-driven — it is system-driven

Final Thought

Replacing the diesel engine is only the first step.

The real transformation in mobile machinery lies deeper:

• hydraulic system architecture

• operating strategy

• control logic

• integration complexity

• and now increasingly cyber resilience

At DMCA Solutions, we help industrial teams navigate exactly this transition — where engineering decisions directly shape sourcing strategy and supplier architecture.

Because in modern mobile machinery:

efficiency is no longer defined by what powers the machine but by how the machine uses that power