Comparing IE3 and IE4 motors

Choosing the right motor efficiency class is crucial for meeting specific application needs and achieving energy efficiency goals.


At Hoyer, we are committed to the continuous advancement of motor technology and providing our customers with solutions that not only meet but exceed their expectations. Whether it’s about upgrading existing systems or designing new installations, understanding the differences between IE3 and IE4 motors can significantly influence your decision-making process.

What are IE3 and IE4 motors?

IE3 and IE4 motors are classified based on their energy efficiency levels as defined by international standards.

IE3, or Premium Efficiency motors, are designed to offer significant energy savings over IE2 models without the highest upfront costs. IE4 motors, classified as Super Premium Efficiency, further reduce energy consumption and operational costs.

IE3 motors are commonly used in industries where energy costs are a concern, but initial budget constraints are tighter. On the other hand, IE4 motors are often utilised in applications where the highest efficiency and longer-term savings are prioritised.

These motors are part of a global movement towards greater energy efficiency, driven by increasing energy prices and environmental concerns.

What are the advantages of IE4 motors over IE3?

Opting for IE4 motors brings considerable advantages, particularly in terms of long-term energy savings and operational cost reductions.

These motors are designed to minimise electrical power losses and reduce the overall environmental impact of your operations. Industries that operate continuously or have high power demands, such as manufacturing or heavy industry, will find the investment in IE4 motors advantageous. By reducing energy consumption, companies can achieve lower operational costs over the motor’s lifespan, which can offset the initial higher investment.

Why choose IE3 motors?

IE3 motors are a suitable choice in scenarios where the balance between cost and efficiency needs to be managed.

IE3, compared to IE2, offers a significant improvement in energy efficiency and are often sufficient for meeting general regulatory and operational requirements. This makes them ideal for industries where the highest efficiency levels of IE4 motors do not justify the additional upfront cost. Moreover, IE3 motors are widely available and can be a more feasible option when immediate replacements or upgrades are necessary.

How to decide between IE3 and IE4 motors?

When deciding between IE3 and IE4 motors, several key considerations should be evaluated:

  • Application-specific needs: Determine the motor performance requirements based on the operational environment and usage.
  • Budget constraints: Consider the total cost of ownership, including purchase price, installation, maintenance, and energy costs.
  • Energy saving targets: Align motor selection with your energy efficiency goals and sustainability initiatives.
  • Environmental regulations compliance: Ensure that motor selection adheres to local and international energy efficiency regulations.

At Hoyer, we are committed to guiding our customers through the choices between different electric motors. Contact us for guidance on your motor needs.

Frequently asked questions about IE3 and IE4 motors

  • Can IE4 motors be used in place of IE3?

Yes, IE4 motors can replace IE3 motors, offering higher efficiency and potential cost savings in the long run.

Learn more about the differences between all IE motor classifications here.

  • What is the ROI period when upgrading from IE3 to IE4?

The return on investment (ROI) can vary based on energy usage, operational hours, and energy costs, but typically, the higher the usage, the quicker the ROI.

  • How do IE3 and IE4 motors impact maintenance costs?

Both IE3 and IE4 motors are designed to have lower maintenance costs compared to lower efficiency motors. However, IE4 motors, in particular, may contribute to further reductions in maintenance costs due to their superior construction and efficiency.