Tier 4 Final Engine Regulations – A Quick Explanation of the Regulations and the Expected Effects

Tier 4 Engine from John Deere
Tier 4 Engine from John Deere

Now that Tier 4 Final Engine Regulations are upon us, you might have some questions about them. They can be somewhat difficult to understand, particularly for folks without technical knowledge of diesel engines. When it comes down to it, they really aren’t that difficult to understand when explained in plain, non-technical words.

What are Tier 4 Regulations?

Tier 4 refers to the highest tier of standards in regards to emissions reductions of diesel engines, particularly off-road diesel engines as found in tractors, earth-movers, and other types of equipment. It specifically refers to nitrogen oxide and particulate matter in the smoke – basically, what makes the exhaust dark. These regulations determine the amounts of pollutants allowable in the emissions of non-road diesel engines.

Tier 4 Regulations are, for the most part, aimed at companies that keep an entire fleet of non-road diesel engines, and can include those that make use of diesel generators for power on a regular basis. Owners of single pieces of equipment will not have to run out and buy a new, Tier 4-compliant piece of equipment.

Why are Tier 4 Final Engine Regulations in place?

The Tier 4 Final Engine Regulations signify the end of the Tier 4 implementations. This has been a process that has been underway since 2006. Tier 4 is the strictest tier of non-road diesel engines, cutting down on pollution. The Final regulations cover all non-road diesel engines up to 750 horsepower.

It is anticipated that these regulations will be the final changes for the near future, and will help to greatly reduce the fleet emissions of construction companies, work crews, and even small farms. Significant reductions will help to improve quality of life in our country. Less emissions means that living near a construction site will not be as toxic, either.

What do tractor owners need to know?

These regulations apply only to new equipment manufactured, not to existing equipment. If you own a tractor already, you don’t have to worry about bringing it into compliance. However, going forward all new engines sold in the United States will have to be compliant with Tier 4. You will be able to continue using earlier engines, as well as finding the parts to repair and rebuild non-Tier 4 engines. You may even be able to find replacement engines, although they will likely be restricted.

If you field a fleet of equipment, there are some restrictions. In this case, you can only use remanufactured pre-Tier 4 engines if they are up to the latest Tier 4 standards, or if you are retiring a pre-Tier 4 engine and replacing it with a Tier 4 engine at the rate of 1 to 1. This means that anytime your fleet replaces a pre-Tier 4 engine with a similar engine, they have to remove another pre-Tier 4 engine and update the machine with a current, Tier 4 Final engine. Another option will be to use “Best Available Control Technology,” also referred to as BACT. BACT is technology that is available for specific machine and engine combinations that can be retrofitted to bring a pre-Tier 4 machine into compliance with Tier 4 restrictions. This technology is only available for a handful of machine and engine combinations.

Will pieces of equipment with Tier 4 Final Regulation-compliant engines work differently?

There will be a handful of new switches and dash lights in the new compliant equipment. Each machine will have different switches and lights, and you will need to consult the owner’s manual in the new piece of equipment to determine which new switches control what functions, and which lights may indicate problems. Every new user will need to know what to look out for, and how it may differ from previously used pieces of equipment.

Additionally, while the new equipment may functionally be the same, you may not be able to maintain some of the systems on your own. You will also need to make sure to use the proper oils and fuels in the new machines – they will not be tolerant of using the incorrect fuel or oil, which can damage the internal components of the engine. The usage of high-sulfur fuel can cause operational issues.

Lastly, the use of a diesel exhaust fluid may be necessary. This fluid will need to be refilled much like the fuel in your equipment is refilled. Some equipment may position tanks for fuel and diesel exhaust fluid side by side for easy refilling.

What solutions are being used to create emissions that meet Tier 4 Regulations?

There are a wide variety of solutions that have been, and will be used to reduce the emissions of engines that meet the Tier 4 Final Regulations.

  • New engine control modules with improved sensors. These will be able to precisely control how the engine operates, and will be able to maximize power output will minimizing the burning of fuel.
  • Solenoid-controlled electronic injection systems can regulate the flow of fuel more precisely.
  • Changing the shape of components, such as adjusting the geometry of the combustion bowl to improve combustion.
  • Changing the materials used in producing components. Pistons can be manufactured using a stronger, more durable and more efficient material than aluminum. These would be more expensive, but also more effective.
  • The use of cooled exhaust gas recirculation (EGR). This is a popular idea, which takes some of the exhaust and recycles it. It can be used to lower combustion chamber temperatures and to reduce emissions when an engine has only a partial load.
  • Aftertreatments that address the exhaust beyond in-cylinder technological advancements. One of these ideas is the Diesel Particulate Filter, which physically captures particulates in the exhaust stream before they reach the end of the tailpipe. A second idea is the Diesel Oxidation Catalyst, which would be put in place before the exhaust pipe, and would contain materials that can oxidize unburned hydrocarbons, reducing the pollutants emitted.

Different manufacturers are using different technologies and taking different courses of action to bring their equipment into compliance with Tier 4 regulations. Consult with your local salesperson or with your company representative to see what the manufacturer is doing, and what they may recommend in regards to retrofitting an existing piece of equipment. There is likely to be a difference even from engine to engine from the same manufacturer – some engines might have required only a minor tweak to bring into compliance, while others may have needed an entire overhaul.

Will Tier 4 Regulations cause costs to rise?

Unfortunately, yes, engines that are Tier 4-compliant will likely be more expensive to produce, more expensive to buy, and will require Ultra Low Sulfur Diesel and after-treatment chemicals that will cause daily use expense to rise. On the good side of things, Tier 4 engines will likely have improved efficiency, and may be able to get 5% more run time out of the same amount of fuel as Tier 3 engines. Due to the new technology that is part of the new Tier 4 machining, they may end up being slightly more expensive to repair as well.

What can result from not bringing a fleet into Tier 4 compliance?

For the individual tractor owner, there’s nothing likely to happen. But for the fleet owner, they may see some or all of the following:

  • Loss of bids due to bid specifications and site permits that may call for Tier 4-compliant equipment to be used.
  • Local and state agencies will be stepping up inspection and enforcement in the wake of these final regulations, so fines could be more likely to occur.
  • Potential profit loss due to required downtime for a vehicle to be upgraded at the last moment.

Tier 4 Final Regulations are nothing to be seriously worried about, and while they will have an effect on everyone in the industry in one way or another, it will not be damaging. The good news is, there are plenty of resources out there that can help fleet or individual owners work with these new standards, so no one is going it alone. Every dealership should be well-briefed on these regulations and the current situation, and should be able to provide a helping hand.


  • Wow! All that to say absolutely nothing about what tier 4 actually is. May have extra lights and switches. WHAT FOR?!!! May need exhaust fluid. WHAT FOR AND WHAT DOES IT DO?!!! Never mind, I’ll find another “explained” article that actually explains something.

  • I’ve seen Tier-4 running very badly (extreme cold weather and the like) on OTR vehicles. What (if any) accommodations exist to mitigate freezing exhaust fluid or malfunctioning fluid systems in construction and farm vehicles? This last winter was tough, and these systems need to be functional to -40F or they are useless.

  • More costs to make farmers less competitive with foreign countries. Must have been a payoff from political contributors.

  • Just more government regulation. Everything that the government gets involved in creates more cost and will kill businesses and jobs.

  • How did we ever survive the 20th Century without all of these crazy regulations? The Democrats are for the little guy, that why they put all of these expensive burdens on us!

  • I have not been impressed with the dealership electronic skills with regards setup and repair of farm and construction equipment. You are too optimistic as to their skill set. That includes but not limited to John Deere and Case/New Holland and Kubota. As a electronic and electrical engineer the lack of understanding that these dealerships have of emission systems is evident every time I been to the dealership. As far as trouble shooting skills they are non existent. It is easy to charge a customer $125 an hour has you guess your way through the system that is in question. A one hour job may cost a customer several hours because of the lack of skill set to quickly and accurately diagnosis a problem. Tier 4 engines create a whole new nightmare for the customer.

  • The EPA is totally out of control. Most of us know it and seem frozen in place unable to do anything about it. Emission controls on farm equipment will only produce a tiny (if not trivial) % of reduction in pollution compared to automobiles and trucks. Fractions of one percent. So the basis for all this is flawed. Secondly, a very simple subset of Tier4 cleanup would have achieved most of the cleanup while being radically more simple and cheap. This entire topic is a near-perfect example of the overreach of the Federal Govt and totally out of control EPA, answering to no one and devoid of common sense.

  • Thank you for pointing that out Dave, we have fixed that error.

  • We’re sorry you feel that way, Mike, unfortunately, we can’t explain how every company will address Tier 4 Regulations. Every company is going to be addressing it differently, a number of companies are using different methods within their own roster of engines. If you want an explanation of specific models and how they address Tier 4 regulations, you should contact a dealer.

  • I am not impressed with tier 4 requirements. What a lot of expense and hassle to support unproven theories. The expense to operate is going to be significant and cause thin profit margins to be thinner yet. I sure am thankful I am not on the front lines where this equipment could be required. Chalk another one up to government regulations due to EPA hype.

  • It won’t freeze completely until it reaches -11°C. It starts freezing at -10°C.

    Freezing does not affect its performance once thawed. Also, AdBlue® tanks tend to be next to exhausts, which keep the temperature of the contents above freezing when the engine is running. Where the AdBlue® tank is situated elsewhere, it is heated using engine coolant which is circulated through the tank.

    I’m on my second T4 compliant (on road) vehicle, open air parking occasionally below zero Fahrenheit. Zero problems. DEF isn’t used by the engine, but is thawed and/or kept liquid by engine-generated heat. Personally I’d be more concerned about diesel fuel gelling before I’d break sweat over DEF freezing.

  • In Australia we have the same emission controls on our engines. EGR feeds a lot of carbon and sludge back into your motor causing wear and blocked manifold.
    The particulate filter blocks if you run the motor for short periods, hence needing it burnt out.
    There are other problems as well.
    So your motor wears out quicker and it causes about the same amount of pollution to make a new motor. Crap idea I think.

  • The article says that Tier IV (4) will not be a big deal. Bull. I work on this stuff for a living. I can tell you that thus far, tier 4 engines have been a nightmare compared to Interim tier 4 and earlier engines. Electronic issues. Engine issues. They use more fuel (a LOT more…regen injects fuel at BDC, that fuel isn’t burnt to produce horsepower, it is used to heat the DOC and DPF to burn off ash and change the characteristics of the exhaust chemicals). Regen on a certain small tractor uses about 1/2 gallon of fuel in a 20 minute regen cycle. That fuel isn’t used to make torque and power-it’s “wasted”. Costs? Yes. It costs more to run. Costs more to maintain. Costs more to buy. Costs more to fix. Ultimately who pays the costs? The consumer. Farmers are required to have tier 4 engines in their new equipment. The tractor has a DPF failure outside the warranty period. $2500 fix. He has to charge more for his crop. The crop buyer charges the supermarket more. Supermarket charges the customer more. Same thing happened with 18 wheelers when DPF’s were mandated on those. They have to up their prices to cover higher maintenance and repair costs and use of more fuel. So we, the consumer, have to pay more for the stuff that gets hauled on 18 wheelers (almost everything).

    If that weren’t bad enough, if a dealer has to replace an engine, he has to destroy the old engine before a new one can be shipped. Not part of the tier 4 deal, but it is part of the USEPA’s regulations. I’ve already had to do several. You drill or knock a big hole in the side of the block, take pics of it with the engine’s serial number, send it to the manufacturer. If they like the pics, they send you an engine. They don’t like them, they tell you to drill or knock more holes and take more pics. The old engine is therefore deemed useless, which is what the EPA wants, so that those engines cannot be rebuilt to be used again.

  • Government rules and regulations add up to the demise of any free market economy. the Democrats live under the notion that big government can fix all your problems when it in fact destroys all that really matters. free will + choice = freedom.

  • Government happens to have an inverse Midas touch when it comes to environmental regulations (and, most other things, as well). Everything that the government touches, with rules and regulations, turns to crap.

    The more one regulates a good or service, the less of the good or service that the customer will receive. Also, the more the regulation, the higher the price of the good or service, if it has not been regulated out of existance altogether.

    The problems that we face as a nation of free and independent individuals cannot be solved by the addition of more layers of government. Government cannot solve the problem when GOVERNMENT IS THE PROBLEM.

  • This pure poppycock,you have yet to prove to me that Nox emissions are that harmful(they are a consequence of the high combustion temp of a diesel-ever sniff a coal fire?)It doesnt matter,increased fuel consumption , equals more CO2 emissions(energy and matter are equivalent-thus you cannot destroy energy or matter).
    Anyrate,I hate a stinky smoke belching Diesel too,but the smell of a good clean running Diesel is the smell of properity-they are clean enough!

  • Your Comments
    I was the service manager in our Dodge – Toyota shop from 1973 to 1984. Car emissions started in ernest in 1973 and I can state first hand that it was a nightmare. Our technicians had a very difficult time adapting to the new technology. The training that was available at the time was not adequate because it too was in the beginning stage of development. Nobody predicted how the new systems would function in weather extremes, etc. I could go on and on but you can see where I am going with this. Over time it will all get sorted out but in the mean time get ready for a very rough ride.

  • “The Tier 4 Final Engine Regulations signify the end of the Tier 4 implementations. This has been a process that has been underway since 2006.”… in case those folks who are (knee jerkingly) blaming Obama and Democrats (both, who like Bush and republicans, have F’d up plenty). It’s not a D or R thing…. it’s a common sense thing. Or lack there of.

  • All you need to know is that this is your Govt interfering with a marketplace under the guise of “public safety” in this case the “Environment”
    things are ALWAYS worse after uncle sam gets involved.

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