Demystifying the EGR Diesel System

EGR part in use inside car

If you’re not a car enthusiast, you’ve probably only heard the term EGR when the local mechanic was giving you bad news about the repairs required to fix your vehicle.

It likely went something along the lines of, “Your EGR valve is having problems,” or “You need to change your EGR sensor.”

When it comes to either diesel engines or motors, EGR systems are a key component in increasing gas mileage and lowering carbon and CO2 emissions, all while lowering the working temperature of your engine.

If you like cars, you should know all about the EGR diesel system, how it works, and why it is used in 99% of diesel engines produced by automotive manufacturers.

What Exactly Is an EGR Diesel System?

EGR stands for “Exhaust Gas Recirculation.” Contrary to what you might imagine, this is a very simple process of recirculating part of the exhaust fumes back into the power stroke.

In layman’s terms, it means what would normally come out of your exhaust pipe is sent back into the engine to get burnt again—re-using the same air and diesel a second time around.

Why Use an EGR System?

There are a few different reasons to consider an EGR system. The first reason concerns pollution.

When your diesel engine compresses the diesel and creates combustion, not all the diesel gets burnt off. To avoid excess diesel-infused CO2 from entering our atmosphere, the system is designed to recirculate some of the exhaust.

The recirculated diesel is burned along with the unused diesel to get a cleaner burn, preventing global warming, smog, and a whole host of other environmental problems. This is done by using more of the diesel that would have been wasted out of the exhaust pipe, thus causing less pollution.

close up of used car EGR

It’s Efficient

The second reason for the system is efficiency. With the rising prices of fuel and the costs associated with burning fossil fuels, the less you waste, the cheaper it is, in terms of fuel costs.

The EGR uses less fuel as part of the combustion, as the diesel/air mix is partly used exhaust fumes, rather than 100% fresh fuel. By adding up to 50% exhaust back into the system, you need less diesel to cause the combustion that powers the motor, saving you money and fuel.

Doing this allows the computer to control the heat and get more efficient use out of the engine. This results in a lower running temperature and better efficiency. Consequentially, an EGR is sometimes called an “EGR cooler” when referring to the overall system.

These days, every major diesel car or truck manufacturer is using an EGR system in their engines. Ford introduced it in the late 1970s on their bigger model pickups and commercial fleet vehicles. Since then, all other major manufacturers have incorporated the idea and concept in some form.

With the help of EGR systems, the heavy polluting diesel engines of our youth are now much more environmentally friendly and can produce up to 60% fewer carbon emissions, though that’s still not a mandatory requirement in vehicle and engine production worldwide.

EGR valve isolated

EGR Regulations

EGR systems are regulated and mandatory in most developed countries, including Canada, the U.S., the UK, and Europe. They are not used in older models and developing countries where the rules governing pollution by vehicles are less regulated.

The EGR systems for large trucks and pickups now come with a huge degree of customization based on personal preference and need. In some cases, people opt to add additional aftermarket or performance versions of EGR systems to their trucks, cars, and buses.

Aftermarket performance EGR systems are some of the most sought-after custom jobs that enthusiasts make to their diesel truck engines, and, in most cases, come combined with ram air or super chargers. These systems are specially designed to increase power and/or efficiency.

Final Thoughts

Most diesel engines in the trucks and SUVs we love to drive wouldn’t meet federal pollution and fossil fuel guidelines without their EGR systems. As the world continues to become more polluted, we can still enjoy our big trucks without losing power or having to pay more taxes for our workhorse vehicles.

What fun would your F350 be with a 3.0-liter engine or, worse yet, a fully electric one? It would lack the power required to tow, haul, or move our goods and equipment.

There is nothing more exciting than the throaty growl of a diesel engine as it thunders under the hood of your truck. EGR systems help to make them more efficient, convenient, and responsible to both our pockets and our environment!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s