Mechanical Pumps vs Electric Fuel Pumps: A Comparison

When choosing a pump, you want to make sure you select whichever is the most efficient at moving fluids from point A to point B. Sounds simple, right?

Well – maybe not.

The fact is, not all pumps are created equal. In the world of pumping technology, the choice between mechanical and electric pumps is dictated by an array of factors, from the nature of the fluid being pumped, to the specific flow requirements. 

Here, we discuss the differences between mechanical and electric pumps, examining their principles of operation, performance, and the distinct applications they’re best suited for.

Pump Basics: Mechanical vs. Electric

Pumps are critical components in various industries, facilitating the movement of fluids from one place to another. The type of pump used depends on the application, and it can either be mechanical or electric. 

Before we discuss fluid & flow requirements, let’s lay out the main differences between mechanical and electric pumps.

Mechanically Driven Pumps: 

Mechanically driven pumps generally have their input shafts coupled to the crankshaft of an engine, the input shaft of a mechanical or automatic transmission, or the output shaft of an electric motor. Until recent years mechanically driven pumps dominated oil and fuel applications in on and off-highway, agricultural, and construction equipment industries. Mechanical pumps can be either positive or variable displacement in construction with unique benefits.  

A mechanically driven / positive displacement pump is generally one of the least expensive pumps to manufacture. They’ve gained a reputation for being one of the most cost-effective ways to provide fluid for several applications.  For ICE applications, they are generally mounted on the crankshaft and produce a flow output that follows the engine’s speed.  Engine lube pumps are generally sized at the worst-case operating condition for the engine and pump (hot idle).  This generally results in the pump producing more flow than is needed at higher RPMs.  A pressure-regulating valve is generally added to the system to limit the increased available pressure.

A mechanically driven / variable displacement pump can be significantly more costly to the manufacturer due to the complexity of the flow control device and control mechanisms. However, the ability to vary the output flow to match the engine’s demand saves power, which ultimately reduces fuel consumption for the end user. The application of these devices has grown significantly over the past decade and they are now commonly found in engine lubrication and automatic transmission applications.

Electrically Driven Pumps:

Electrically driven pumps can also have their input shafts driven by the output shaft of the electric motor. The most significant advantage of an electrically driven pump is the speed of the pump. Therefore, the output flow of the pump can be controlled completely independently of the device they are providing flow to. 

In the case of a small ICE, the speed of the electrically driven pump can be increased so that the pump doesn’t need to be oversized at the hot-idle condition typical of a mechanically driven pump. This allows for the use of a smaller pump head which generally reduces the manufacturing costs of the pump head itself. 

Additionally, it allows for the flow output of the pump to exactly match the flow demands of the engine or transmission. By doing this, it eliminates the flow control components of a variable displacement mechanical pump thus saving manufacturing costs.  

Another advantage is that by matching the flow output of the pump to the device it’s lubricating power consumption is minimized and energy costs are reduced for the end user.

Wrapping Up the Pump Debate: Mechanical vs. Electric

While mechanical and electric pumps may serve the same fundamental purpose, their differences in operation, performance, and suitability for specific applications make them unique. Whereas one job may benefit from the robust nature of a mechanical pump, others may require the flexibility and precision of an electric pump.

Remember, the right pump can significantly boost your operations’ efficiency, ensuring smooth sailing no matter what your industry throws at you. 

If you’re looking for more information on all things pumps - check out our blog. Alternatively, you can also contact one of your experts with any questions you may have.