2010 EPA Mandate FAQ

What are the new 2010 EPA emissions requirements?
In 2010, the EPA is requiring new vehicles to achieve a new diesel exhaust emissions regulations limit, which is .2 NOx (g/hp-hr) down from 1.2 in 2007.

What choices are bus manufacturers offering?
Next year you’ll have two choices when you purchase a bus: a bus that reduces emissions in the engine cylinder (MaxxForce® Advanced EGR), and a bus that reduces emissions by adding a second fluid (Urea) through an after-treatment system (SCR). With the Advanced EGR solution, operating and maintenance requirements don’t change for your drivers or mechanics. Compare this to the SCR solution, where changes include significant add-on after-treatment equipment, additional attention from your drivers and new maintenance and servicing requirements for your technicians. With SCR, the burden on you is clear, and that’s why we believe advanced EGR just makes sense.

How does Advanced EGR work?
EGR (Exhaust Gas Recirculation) is an emissions reduction technique used in most gasoline and diesel engines. EGR works by re-circulating a portion of an engine’s exhaust back to the engine cylinders and burning off excess pollutants. When temperatures in the combustion chamber get hot, oxides of nitrogen (NOx) form. When these nitrous oxides combine with hydrocarbons, they produce the ugly haze we call smog. EGR re-circulates this exhaust into the intake stream. Since the exhaust gases have already combusted, they don’t burn again. These gases displace some of the normal intake, slowing and cooling the combustion process, which reduces NOx formation. The challenge for 2010 is to precisely control the flow of re-circulated exhaust. MaxxForce Advanced EGR engines have increased injection pressure, improved combustion and refined calibrations with that goal in mind. The result is an engine that treats NOx in-cylinder, and therefore requires no extra effort from our customers.

Why is Navistar the only OEM offering an in-cylinder solution?
We pursued Advanced EGR because it was simply the right thing to do when we looked at it from a customer standpoint. Our customers don’t need extra hassles or higher operating costs, and MaxxForce Advanced EGR is the only solution that avoids both. We developed a high-pressure fuel injection system years ago, knowing that this technology would allow us—and only us—to deliver a superior emissions solution.

What are the main differences between EGR and SCR?
With Advanced EGR there are no extra fluids to buy, store or deal with. There is no new hardware to add. And there is no new training needed. SCR requires all of the above.

Will mounting be easy?
With Advanced EGR, there will be no additional hardware on the chassis and there will be minimal additional body builder chassis packaging requirements.

Will it affect engine reliability and durability?
While other OEMs have been working to re-engineer their engines to include SCR technology, Navistar hasn’t. In fact, Advanced EGR solution based upon the technology solution we brought to market in 2007. This approach means you will not have to rely on unproven technology.

Will it be hard to maintain buses with Advanced EGR?
Our solution does not require the use of urea and therefore requires no additional equipment to learn or new fluids to deal with. It will be just like operating and driving the bus you drive today. For every hundred gallons of diesel fuel consumed, SCR systems will require 1 to 4 gallons of urea. These urea tanks will need to be filled periodically or the bus will become disabled.

Will SCR provide a lower operating cost?
SCR will not yield a lower operating cost; in fact, SCR will likely result in a higher operating costs when you consider the need to purchase urea. Purchasing urea in the United States today can cost over $35 per gallon. Even in Europe (where it’s much more commonly available) the price is as much as 20 euros for a 10 liter container at retail. That equates to $12 per US gallon. Add in the cost of extra maintenance and training and the operating cost equation is clearly in favor of Advanced EGR.

Will engine operating temperatures be dangerously high with Advanced EGR?
Not at all. Cooling capacity will be sized to keep operating temperatures at optimum levels, just like today. Cooling loads have increased over the years with power increases, air-conditioning, and stringent emissions regulations. Cooling capacity has always kept pace and will continue to do so.

Won’t adding an SCR catalyst be just like adding another DPF?
The catalyst itself is only a minor portion of an SCR system. A 10-15 gallon urea tank complete with insulation and heater, and a doser system to meter and inject urea are also in the picture. Taken together, SCR system components will take up more space than a 100 gallon fuel tank and will add 200 lbs. – 300 lbs. weight. Packaging will be a critical challenge, especially in cases where you need space for luggage storage, wheelchair lifts or air conditioning.

Will in-cylinder systems be 2010 compliant?
All MaxxForce engines will be compliant for 2010, just as they are today. If they weren’t, we couldn’t sell them. Some Navistar engines are currently below 2007 NOx levels, as the EPA encourages and rewards this. As a result, we will be able to phase into 2010 emissions regulations with in-cylinder technology because our engines are cleaner, earlier than required. Customers benefit through the longer and smoother transition.