Ask The Experts: How Have EPA Emissions Regulations Affected Diesel Engines?

As you probably know, modern diesel engines are held to a strict set of regulations regarding their emissions.

Diesel Semi TruckThese regulations have allowed for alterations in the way diesel engines operate and have been the root cause of a lot of the modifications we're familiar with now.

These emissions regulations are not a new thing. But many people don't know just how far back these regulations go. This post will take you through how these regulations came about and what they mean for your engine.

Click To Talk Directly To A Diesel Engine Expert 8-5 EST

What Regulations Affect Diesel Engines? 

A Brief History of Diesel Engine Emissions Regulations

The Clean Air Act, created in 1963, is the legislation that calls for the monitoring and control of air pollution, as well as research into lessening the pollutants. 

The Clean Air Act of 1970 is what allows the federal and state governments to impose restrictions on pollutants and emissions. It has been amended several times through the years to establish the regulations as we know them now.

Federal regulations on engines began in 1974, but it wasn't until 1988-2004 that they really became strict.

Emissions regulations, enacted by the Environmental Protection Agency (EPA) began to affect heavy-duty on-highway applications more strictly in 2002. These regulations put in place fines for all engine manufacturers who did not comply with the regulations set for all engines after that date.

Even more regulations were passed between 2007 and 2010, including PM, NOx, and NMHC limits. The standards put in place in 2010 are the fully phased emission regulations and are sometimes called the "US 2010 Standards."

Additional standards and regulations limit sulfur content in on-highway diesel fuel. These limits became effective in the early 90s and were aimed to help engines meet the emission standards.

Complying With Emissions Regulations

All manufacturers must prove their engines are in compliance with EPA regulations by submitting an application for a certificate of conformity and performing the necessary testing. 

They must do this for each engine they wish to sell. (Check out the EPA's guidelines for more in depth information on this process).

Because of these requirements and the cost associated with continually needing to modify engines, manufacturers like Caterpillar have limited their on-highway options to focus more on off-highway applications with less regulation. 

Click To Shop Diesel Engine Parts

What Changes Have These Regulations Brought?

How Did Manufacturers Handle These Restrictions?

All on-highway heavy duty vehicles are subject to these standards. California, a major force behind the push for these regulations because of the emissions in busy cities such as Los Angeles, have even tighter regulations that need to be followed.

These new regulations led to innovation. Most engine manufacturers created an EGR, or exhaust gas recirculation, engine. Caterpillar, however, responded to these regulations with a different version. They created the ACERT engine, or Advanced Combustion Emissions Reduction Technology.

About the EGR System in Diesel Engines

The exhaust gas recirculation system (EGR) was designed to help control emissions, specifically to reduce the amount of NOx gas emissions. 

It's made up of several major parts, including the EGR cooler and the EGR valve. These components, and the system as a whole have caused problems for operators in the past, but the technology has improved greatly since it was first introduced. 

The EGR cooler is responsible for pulling the heat from the gases before they go back into the combustion chamber. 

The exhaust gas is very hot, and isn't ideal for combustion. So, the EGR cooler cools that gas down to better support the combustion process.

Manufacturers have implemented this system in most modern diesel engines to remain compliant with emission regulations.

Additionally, natural gas engines are becoming more common.


Highway & Heavy Parts Can Help With Your Diesel Engine Needs!

HHP has a wide selection of diesel engine components to help with your repairs! Our team of experts is here to help you find exactly what you need.

At HHP, we have:

  • ASE Certified Technicians on staff to help diagnose your diesel engine problems

  • Fast and accurate quotes

  • A huge inventory of replacement parts

  • Fast and easy ordering—call or shop online!

  • Fast shipping

  • Industry leading warranties

From diagnosis through delivery, we're Highway & Heavy Parts!


Related Articles:





Related Videos:

Give Us A Call!


Short on Time? Take your Quote Online!

We get it- when you need Diesel Engine Parts, time is of the essence. That's why we've developed the HHP Online Quoting System.

Just fill out the form with your name, engine information, and the parts you need, and our ASE-Certified Technicians will get back to you with an estimate. It's as close to magic as a diesel engine gets!

Get A Quote Online!