We know you have many questions regarding the EPA 2010 regulations and how SCR and DEF will affect your business. Below are some answers to the most frequent questions we get at Hino If you have more questions, please do not hesitate to contact us via phone at 248.699 9300


What is DEF?

DEF is an abbreviation for "Diesel Exhaust Fluid", a solution made from 67.5% purified water and 32.5 percent automotive-grade urea that serves as a carrying agent for the ammonia needed to reduce nitrogen oxide (NOx) emissions from diesel engines. When DEF is injected into the engine exhaust gas, downstream of the DPF, it will be rapidly hydrolyzed producing the oxidizing ammonia needed by the SCR catalyst to complete NOx emissions reductions.


What is EGR?

EGR is an abbreviation for Exhaust Gas Recirculation, which lowers combustion temperature and decreases NOx by re-circulating exhaust gas back into the engine. This technology has been adopted by both gasoline and diesel powered vehicles to meet increasingly stringent emission levels.


What is a DPF?

Diesel Particulate Filter. A device which physically captures diesel particulates preventing their discharge from the tailpipe. Collected particulates need to be removed from the filter, usually by continuous or periodic oxidation in a process called "regeneration."


What is SCR?

SCR is an abbreviation for Selective Catalytic Reduction, a general term for aftertreatment equipment which promotes a chemical reaction by using a catalyst for eliminating or detoxifying particular chemical ingredients. To meet the EPA2010 regulation, the vehicle out NOx level will be extremely close to zero (0.2 Grams per brake horsepower). By mixing the NOx with the ammonia contained in urea, it will be separated into harmless water and nitrogen. It is an extremely effective, dependable, efficient and economical selection. SCR has already been adopted in Europe and Japan for truck and mobile vehicle applications, so it only makes sense to be used as a solution for EPA2010. Almost every U.S. diesel engine manufacturer plans to adopt SCR technology, further proving its reliability.


Will Selective Catalytic Reduction (SCR) have any influence on the oil change intervals required to properly maintain my engine?

SCR uses a flow through aftertreatment device downstream from the DPF, so it does not put any excess load on engine itself and therefore will not change the required engine oil change interval.


How much DEF does Hino expect the engine will use?

Our testing results show that the 6 cylinder medium duty engine will use a range of 1-2% DEF for each gallon of fuel consumed. The exact percentage will vary based on the duty cycle of the



Will the exhaust gas from an SCR truck smell like rotten eggs or other chemicals?

No, our SCR system injects DEF into the hot exhaust gas, downstream of the DPR, in the exact quantity needed for a chemical reaction to transform it to harmless water H20, Carbon Dioxide (CO2) and nitrogen. This reaction does not result in any unusual or strange smells.


Where can I buy DEF?

Hino along with other engine and vehicle manufacturers have been working together on infrastructure development for the U.S. market place. All US based Hino dealers will stock and sell DEF in 1 gallon or 2.5 gallon jugs. They will also have the option to sell DEF in 55 gallon drums or 330 gallon totes, along with the necessary pumping equipment for use at major customer locations. In addition, Fuel stations and Truck Stops all over the United States and Canada will have DEF available in various packaging, including bulk DEF pumps at the largest fuel distribution locations. For more information on where to get DEF and how to stock in bulk see the DEF SECTION of this site



I heard that DEF freezes at 12 degrees Fahrenheit, will this affect vehicle operation or vehicle emissions?

DEF will begin to freeze at around 12 degrees Fahrenheit (-11 degrees Celsius), however we have integrated a defrosting system which will melt the DEF shortly after engine startup. This will enable the injection of DEF within the time frame necessary to meet the EPA regulations.


Does DEF itself smell? I'm worried about storing it in our warehouse.

DEF contains 67.5% H20 and 32.5% urea solution which has an aroma similar to Ammonia. As long as the DEF is packaged and mixed properly and the packages remain closed it will not smell. Since DEF is an aqueous solution, even if it spills onto the floor, it can be easily cleaned up with tap water. DEF is considered non-hazardous, in fact, agricultural grade urea is used as Fertilizer all over the world, industrial grade urea is used for SCR in power plants and consumer grade urea is used in food, and medical products.


When will Hino Trucks SCR equipped vehicles will be released?

SCR equipped vehicles were released in the model year 2011. In order to be certain that those vehicles perform to your demands, we have a number of customer demonstration units in operation throughout the US.


What is the size of the Hino Trucks DEF tank?

The DEF tank on the Hino truck is 4.7 gallons. It is designed to be very compact, minimizing interference with vocational bodies needed for a variety of applications.


How far will the vehicle run on one tank of DEF?

Much like fuel economy, it greatly depends on vehicle operating conditions. We estimate that a Medium Duty Hino Truck which runs 800 miles (1,300km) per week achieving a fuel economy of approximately 10 MPG will run almost 2400 miles (3,900km) per tank of DEF. This would be a DEF economy of approximately 500 MPG. We are currently doing additional testing on our EPA2010 demo vehicles in the U.S to acquire additional data points.


Does SCR influence fuel economy?

SCR is designed to chemically reduce the NOx output of the exhaust gas after the diesel particulate filter. Because this is being completed after the combustion process, it allows the engine design to be modified for maximized fuel efficiency; lowering engine EGR rates, thus increasing the in cylinder oxygen content which can lower engine particulate matter output. Less particulate matter also reduces the amount of fuel used for soot regeneration cycles. In total, we are targeting a fuel economy improvement of 3-5%. A recent independent SAE-type test confirmed Hino Trucks fuel advantage. Click HERE for details


Does SCR influence engine power output?

No, the SCR system does not contribute to changes in engine power.


What will happen if I run out of DEF?

The EPA2010 requirements state that we must eventually stop the engine if the vehicle runs out of DEF, however, we have incorporated a comprehensive on board warning system to prevent un-timely engine shutdowns. In addition, the vehicle will be allowed to operate in a "limp home" condition making it possible to operate the vehicle for a short distance. Finally, in the case of an emergency, DEF will be available for purchase through the HinoWatch roadside assistance program.



Will an SCR equipped truck drive any differently?

Drivability will not change.


Will an SCR equipped vehicle's exhaust brake work the same?

The SCR system adds additional aftertreatment but it does not affect the exhaust brake operation and will not change braking performance.


Does SCR need additional maintenance?

Our SCR system is designed for long term durability and reliability. Therefore, the only added maintenance requirement is the replacement of a DEF sediment filter every 220,000 miles (360,000 km).


Will the DEF tank or system components rust?

We will use a plastic resin material for the DEF tank and piping, eliminating concerns about rusting. We have also selected the appropriate materials for all interacting system components to improve overall durability.


Does DEF evaporate in high temperatures and generate toxic gas?

DEF vaporization should not be a problem provided the vessel is closed and the product is stored between 10 and 90 degrees Fahrenheit. Studies have been done regarding DEF toxicity and it will not create toxic gases. In fact, Urea is routinely processed at temperatures above 140 degrees Fahrenheit. Urea is used for processing and producing foods & drugs, and as fertilizer for plants which are often consumed by humans, it is biodegradable and non-toxic.


I heard that some manufacturers will use a Copper Zeolite Catalyst which may cause the formation of dangerous dioxin compounds (harmful chemicals formed by combustion). Is this true, and how will Hino handle this issue?

Yes, some manufacturers may use a Copper Zeolite SCR Catalyst and it does raise this concern, but Hino will use an Iron Zeolite SCR catalyst which has been proven not to develop harmful dioxins.


Since DEF changes NOx into H2O and N2, how will the water actually be emitted from the aftertreatment system?

Because of the high temperature of the exhaust gas, the water will evaporate into the air as it exits the vehicle exhaust system.


What will the impact be on exhaust temperatures at the tailpipe?

The max DPR/SCR system skin temperatures and exhaust gas temperatures will be the same as current Hino DPR System.


 Hino has selected the most environmentally friendly, reliable solution to meet the EPA2010 challenge - Selective Catalytic Reduction - Learn more about SCR & DIESEL EXHAUST FLUID:







Hino 338 Medium Duty Truck Chassis
Hino 195 Hybrid Truck Chassis - Double Cab




XL7 33,000 GVW


XL8  > 33,000 GVW

HYBRID 195h 19,500 GVW


HYBRID 195hDC  19,500 GVW Double Cab














238 23,000 GVW


258ALP  25,500 GVW Air / Low Profile


258LP  25,500 GVW Low Profile


268   25,950 GVW


268A   25,950 GVW Air


338   33,000 GVW

155  14,500 GVW


155DC  14,500 GVW Double Cab


195 19,500 GVW


195DC  19,500 GVW Double Cab