Since 2000, the United States’ Environmental Protection Agency (EPA) has required diesel engine manufacturers to minimize exhaust emissions on new engines designed for off-road use in the United States.
The EPA Tier 4i (Interim) emissions rules were in effect until the end of 2012, when they were replaced by the Tier 4 Final. According to the EPA, any diesel engine developed after January 1, 2013 for use in an off-road product sold in the United States must comply with the stricter EPA Tier 4 Final compliance rules. The EPA has made provisions for some leeway in completing the changeover.
The major addition of Diesel Exhaust Fluid to the exhaust system was a contentious necessity (DEF). It’s a combination of pure water and urea. A chemical reaction occurs when it is injected into the exhaust, turning the exhaust to nitrogen and water vapor. For the DEF system to work, the engine system must be hot enough to totally burn the gasoline. Diesel particulates build in an exhaust filter if the engine isn’t running hot enough, producing back pressure.
Tier 4 engines must be used in the construction of new pump stations. Existing applications, on the other hand, can continue to use Tier 3 engines that meet certain criteria. There are numerous benefits to refurbishing existing Tier 3 engines rather than replacing them with new Tier 4 engines, according to MWI Pumps expert Joe Hathcock.
Here are seven reasons why rebuilding a Tier 3 engine is preferable to purchasing a new Tier 4 engine.
- Engines of Tier 4 are more expensive. When comparing the cost of purchasing a Tier 4 engine to the cost of rebuilding a Tier 3 engine, the cost of purchasing a Tier 4 engine is around 60% more. Many other components are also necessary, such as DEF fuel and a particle filter that, if blocked, can cause the engine to shut down.
- A pump station modification may be required as part of a Tier 4 upgrade. The larger Tier 4 engines will almost always necessitate a larger platform, which adds to the upgrade time and cost.
- DEF fluid is not required for Tier 3 engines. DEF (also known as AUS 32 and marketed as AdBlue) is a liquid that is used to reduce the amount of pollution produced by diesel engines. To achieve Tier 4 final emission criteria, equipment manufacturers use selective catalytic reduction (SCR). By breaking down particulate matter and nitrogen oxide, this technique injects DEF into the diesel engine exhaust system to achieve the desired emission reduction.
DEF is nontoxic, nonpolluting, nonflammable, nonhazardous, stable, and colorless, which is great news. The disadvantage is that DEF is corrosive to most metals and coatings because it is nitrogen-based. DEF is also more vulnerable to contamination than other fluids.
There are no DPF filters on Tier 3 engines. DPF (diesel particulate filter) is a technology that uses high-tech filtering and regeneration processes to eliminate the majority of solid carbon-based emissions from exhaust. These Tier 4 filters can become clogged and require removal in order to be cleaned, resulting in additional costs and downtime.
There are fewer sensors in Tier 3 engines, thus they are less likely to malfunction or break. A sophisticated engine control system is one of the primary components necessary to satisfy Tier 4 regulations. The engine control unit (ECU) houses this control system, which controls dozens of operating and environmental factors in order to optimize horsepower, torque, and load responses. It enables the engine to retain combustion efficiency throughout a wide range of operating situations while reducing exhaust pollutants. This control system communicates all engine characteristics, including pressure, temperature, regeneration requirements, and engine failures.
However, according to Hathcock, having these sensors has more drawbacks than benefits. The Tier 4 engine sensors tell the engine when it’s time to regen, or clean itself. The sensors must all be working when the diesel exhaust sprays into the engine and burns off. If one of them fails, the system enters “limp mode,” which means it can only perform at 20% of its normal capacity, he noted. When this occurs, the regen must be manually forced. This can result in a large amount of downtime. Tier 3 engines do not have these sensors because they do not use a DPF and so do not require them because they do not burn anything.
The regen procedure for Tier 4 engines may necessitate downtime. Regen is an expensive self-cleaning process for the system and exhaust filter. To burn off the DEF liquid and send it out the exhaust, the temperature must be at a specified level.
Tier 3 engines are capable of handling a broader variety of loads. A Tier 3 engine can run at high speeds or idle for hours. A Tier 4 engine must maintain a high rpmgenerally at least 1600 rpmeven if this is not the most efficient speed for every application. The Tier 3 engine’s ability to run efficiently at a variety of speeds, according to Hathcock, is an advantage.
According to Hathcock, repairing a Tier 3 engine is not difficult. It will need to be taken out of service, stripped down, properly cleaned, and rebuilt with new parts. Hathcock proposes using replacement parts from the original equipment manufacturer and claims that the process can be completed in a matter of weeks. Liners, pistons, cooling injection pumps, and other parts may need to be replaced.
When the efficiency of the Tier 3 engine begins to deteriorate, Hathcock says it’s time to consider rebuilding it. However, if done correctly, a professionally rebuilt Tier 3 engine can live another 5 to 10 years, depending on how often it is used and whether it receives regular preventive maintenance.
If your engine requires repair or you’re thinking about rebuilding a Tier 3 engine, give MWI Repair a call at (772) 770-0004 or fill out a contact form to go over all of your maintenance and servicing choices.
What are Tier 4 engines?
Tier 4 is the most recent emission standard set by the US EPA and the California Air Resources Board for new engines used in off-road equipment such as construction, mining, and agricultural equipment, marine vessels and workboats, locomotives, and stationary engines used in industrial and power generation applications. These emissions standards apply to new engines that power equipment usually found in construction and agricultural applications as of January 1, 2014, whereas new engines designed for significantly bigger uses, such as marine and locomotives, must meet the standard by January 1, 2015. These emissions rules only apply to new and remanufactured engines; older engines are exempt.
Particulate matter (PM) and nitrogen oxides (NOx) emissions from Tier 4 compliant engines are reduced to near-zero levels. Tier 4 compliant engines lower emissions by over 95 percent for most agricultural and construction equipment and just over 86 percent for significantly bigger applications like locomotives and marine vessels when compared to earlier emissions requirements.
The Tier 4 emission standards are identical to the emission reduction criteria for heavy-duty truck engines. While engine manufacturers have created a relatively consistent suite of clean diesel technologies to fulfill truck emission rules, given the significant diversity in engine size and equipment use in off-road applications, a wide array of ways to accomplish emission reduction are visible.
Despite the seemingly limitless array of emission-reduction technologies present in Tier 4 engines and equipment, most manufacturers also include fuel-saving and productivity-enhancing features. Lightweight materials, fuel-efficient engines, hybridization, advanced energy storage capabilities, and the use of global positioning systems and telematics developed to make the most of expensive equipment are increasingly found in off-road equipment that help equipment owners save fuel, conserve energy, reduce greenhouse gas emissions, and, most importantly, improve air quality for everyone.
Tier 1 Standards
Tier 1 NOx emission rules for Category 3 engines were adopted by the EPA in 2003, and they are similar to the international IMO MARPOL Annex VI limits. Depending on the engine speed, these restrictions range from 17 to 9.8 g/kWh, with higher limits for slower engines.
For new engines developed after 2004, the EPA Tier 1 limits are in place. These restrictions will be met without the use of exhaust gas aftertreatment, thanks to engine-based controls. Other than NOx, no emissions are regulated.
Tier 2-3 Standards
The EPA introduced Tier 2 and Tier 3 emission requirements for newly constructed Category 3 engines in a 2009 rule.
- Beginning in 2011, Tier 2 criteria will apply. Engine-based controls, such as engine timing, engine cooling, and advanced electronic controls, are required. Tier 2 requirements reduce NOx emissions by 15 to 25% compared to Tier 1 limits.
- Beginning in 2016, Tier 3 criteria will be implemented. They can be reached by employing high-efficiency emission control technology like selective catalytic reduction (SCR), which can yield NOx reductions of up to 80% below Tier 1 standards.
The relevant IMO Tier II-III regulations are similar to the EPA Tier 2-3 NOx limits. Tier 2 limitations range from 14.4 to 7.7 g/kWh depending on engine speed, whereas Tier 3 limits range from 3.4 to 1.96 g/kWh. In addition to the NOx limitations, the EPA established a 2.0 g/kWh HC emission standard and a 5.0 g/kWh CO emission standard for new Category 3 engines. Although no emission regulation for PM has been established, manufacturers are obligated to monitor and report PM emissions.
Emission Control Areas of the International Maritime Organization (ECA). The IMO has established the North American ECA for NOx and SOx emissions along the US and Canadian shorelines (effective August 2012) and the US Caribbean ECA for NOx and SOx emissions around Puerto Rico and the US Virgin Islands (effective August 2012). (enforceable from 2014).
While in US waters, the ECAs verify that foreign flagged vessels adhere to IMO Tier III NOx limitations (the IMO Tier III standards are only applicable within ECAs). Low sulfur fuel regulations for vessels in US waters are also triggered by the ECA, which are imposed by the IMO and the US EPA.
When did Tier 3 engines come out?
Light-duty vehicle Tier 3 emission rules were proposed in March 2013 and passed into law on March 3, 2014. The Tier 3 regulations, which are very similar to California’s LEV III rules, will be phased in from 2017 through 2025. Sulfur restrictions for gasoline are also tightened as a result of the rule.
Tier 3 standards follow the same structure as Tier 2 standards in that manufacturers must certify vehicles to one of seven “certification bins” and achieve fleet-average emission standards for their vehicle fleet in a given model year. Tier 3 criteria are more severe, and also feature a number of additional significant changes:
- The sum of NMOG+NOx emissions is used to calculate both the certification limits (bins) and the fleet average standards.
- The bins are named by the NMOG+NOx limit in mg/mi that corresponds to them. Bin 160 (NMOG+NOx = 160 mg/mi) is the highest emission bin and corresponds to Tier 2 Bin 5.
- By 2025, the fleet’s average NMOG+NOx emissions must be 30 mg/mi (Bin 30 = Tier 2 Bin 2), according to the EPA.
- The required emission durability has been raised from 120,000 to 150,000 miles.
- Gasoline vehicles are tested with gasoline containing 10% ethanol for exhaust and evaporative emissions (E10).
Emission criteria for heavy-duty vehicles (HDV), such as heavy-duty pickups and vans, chassis-certified as whole vehicles, are also included in the Tier 3 rule.
The Tier 2 definitions are used to define vehicle categories such as light-duty vehicles (LDV), light-duty trucks (LDT), and medium-duty passenger vehicles (MDPV).
The EPA’s Tier 3 web page offers information and regulatory notifications about Tier 3 regulation.
What makes a diesel engine a Tier 4?
Tier 4 diesel engine emissions rules are currently the most stringent EPA emissions requirements for off-highway diesel engines. This regulation limits the quantity of particulate matter (PM), often known as black soot, and nitrogen oxides (NOx) that an off-highway diesel engine can generate.
Tier 4 criteria were phased in beginning in 2008, based on an engine’s horsepower rating. PM and NOx emissions had been lowered by 99 percent compared to 1996 levels by the time the final Tier 4 standards were fully implemented in 2015.
What is a Tier 2 diesel engine?
CO stands for carbon monoxide; g/kW-hr stands for gram per kilowatt-hour; HC stands for hydrocarbons; THC stands for total hydrocarbon; kW stands for kilowatt; NOx stands for nitrogen oxides; PM stands for particulate matter; rpm stands for revolutions per minute.
Commercial compression-ignition (diesel) engines having a power rating of at least 37 kW are subject to Tier 2 emissions requirements set by Congress.
These specifications apply to both propulsion and auxiliary engines, however land-based engines used in portable auxiliary equipment must fulfill land-based engine standards.
A special rule applies to smaller compression-ignition engines. The US Environmental Protection Agency (EPA) also plans to regulate recreational marine diesel engine emissions under a separate rule, with exemptions for category 1 and 2 engines used as auxiliary engines in US-flagged vessels engaged in foreign trade or overseas operations for at least 75% of the time (i.e., operation will occur more than 320 nautical kilometers outside the United States, not including trips between U.S. ports in Alaska, Hawaii, the continental United States, or its territories).
Tier 1 emissions regulations are MARPOL Annex VI nitrogen oxide (NOx) limits (international norms adopted by the International Maritime Convention on the Prevention of Pollution from Ships).
These requirements apply to any diesel engine with a power rating of more than 130 kW installed on a vessel built on or after January 1, 2000, as well as any engine undergoing major conversion after that date. MARPOL standards are now optional for ships traveling within the United States, but will become mandatory for ships traveling internationally with countries that have ratified MARPOL standards. The EPA pushes engine manufacturers to create compliant engines and urges owners to purchase them, despite the fact that they have not yet been ratified by the United States. MARPOL Annex VI NOx regulations will be retrospectively effective on January 1, 2000 if ratified by the United States.
c Emissions requirements are determined by cylinder displacement and rated power. The three groups of standards are as follows:
These engines are typically employed as propulsion engines on relatively modest commercial vessels (category 1 = 37 kW) (fishing vessels, tugboats, crewboats, etc.). Auxiliary engines are also employed aboard vessels of all sizes and uses.
Category 2 (>= 5 liters displacement/cylinder to =37 kW): The largest engines utilized as propulsion engines in U.S. harbor and coastal vessels. Auxiliary power is also provided by these engines on very large ships. Many of these engines have the same size and configuration as locomotive engines, and they use similar emissions control systems.
Category 3 engines (displacement/cylinder > 30 liters, rated power.=37kW): These are exceptionally big, high-power engines that are virtually solely utilized for propulsion on international commerce vessels.
d Tier 2 marine engines with a power output of less than 37 kW must meet the same emission criteria as land-based engines.
g Engine or engine family manufacturers must show that the engine or engine family will meet all criteria for the duration of its useful life. Testing a sample of engines is used to determine useful life certification. Each engine manufactured is covered by a warranty period. Each engine’s manufacturer must provide a warranty to the ultimate purchaser or owner (and each subsequent purchaser or owner) that the engine is designed, built, and equipped to comply with Tier 2 standards at the time of sale and is free of defects in materials and workmanship that would cause the engine to fail to comply with these standards for the duration of the warranty period. Furthermore, this warranty must be at least one-half of the useful life duration and cannot be shorter than any mechanical warranty on the engine. The useful life is measured in hours or years, depending on whatever comes first.
What is DEF on diesel?
We get a lot of questions about DEF and how to use it effectively on your forecourt, so we asked the expertise of Danny Seals, a forecourt solutions expert, to provide us with some simple answers.
What is DEF?
DEF is a urea-water solution that is injected into the exhaust stream of diesel automobiles to convert NOx gases (harmful emissions) into nitrogen and water. Vehicle manufacturers introduced a Selective Catalytic Reduction (SCR) technology to meet EPA emissions limits in 2010. This is a strategy to achieve the requirements without sacrificing engine performance or fuel economy. DEF isn’t a fuel additive, and it’s kept in its own tank.
Who needs DEF, why?
DEF is required for medium and heavy-duty vehicles equipped with diesel engines manufactured after 2010. To meet emissions rules, the vehicle is configured to inject DEF into the exhaust stream. The engine performance will be diminished and lower speeds will be imposed if the vehicle is allowed to run out of DEF.
What are the different delivery modes of DEF?
DEF is available in a variety of forms. A driver can purchase jugs/containers in a variety of sizes. This necessitates the driver physically transferring the DEF into the car. When installed, DEF can also be dispensed into the vehicle using a fueling dispenser.
Which retailers should offer DEF and what indicators can they use to decide?
Because there is such a vast population of automobiles on the road, DEF is an excellent product for all c-stores to offer. Retailers who sell diesel at their gas stations can utilize the volume sold to estimate the number of diesel customers they have. DEF is required by the majority of today’s heavy-duty trucks. Locations with a separate large truck filling station might think about putting DEF in the dispensers. Because they buy DEF in quantity to keep in their tanks, this results in higher profit margins. Some places that sell a lot of diesel on their forecourt should also consider a dispenser option.
How can Gilbarco help retailers get into DEF?
Since the inception of DEF requirements, Gilbarco has been the industry leader in DEF dispensers. Over the years, we’ve worked with large stores to provide dispenser functionality, and we’ve established the industry standard for this service. Gilbarco assists merchants in entering the DEF dispensing market by providing factory-installed options and retrofitting existing dispensers where DEF is stored in bulk.
Is highway diesel low sulfur?
Diesel Standards Overview Beginning in 2006, the Environmental Protection Agency (EPA) began implementing more rigorous restrictions to reduce the amount of sulfur in diesel fuel to 15 parts per million (ppm). Ultra-low sulfur diesel is the name given to this type of fuel (ULSD). The EPA’s diesel guidelines aim to reduce emissions from two types of vehicles: on-road (or highway) vehicles, and off-road (or highway) vehicles.
Do Tier 4 engines use DEF?
Diesel exhaust fluid (DEF) is required for diesel engines with more than 74 horsepower under Tier 4 Final pollution requirements. DEF has long been used in over-the-road trucks and other construction equipment as part of the selective catalytic reduction (SCR) system.
Does Tier 4 have DEF?
Selective Catalytic Reduction (SCR) is used in Cummins Tier 4 Final engines with more than 751 horsepower to reduce NOx in the exhaust. Diesel Exhaust Fluid is an important component of the exhaust aftertreatment (DEF). DEF is a non-toxic solution made up of 67.5 percent water and 32.5 percent automotive grade urea, and it’s one of the SCR system’s most important components.
