How SCR Works
Just say NO to NOx.
The new EPA regulations for 2010 call for an 83% reduction in NOx from 2007’s already low levels. Volvo has always welcomed efforts to minimize environmental impact and this new challenge is no different. Volvo has met this standard with a system that delivers near-zero emissions of NOx and particulates, while saving fuel and reducing driver involvement.
All this —and fuel efficiency, too.
Volvo’s unparalleled SCR system not only meets environmental regulations; it not only relieves drivers of concern about regeneration; on top of all that, it provides improved fuel efficiency when compared to other systems. Volvo addresses other critical areas that effect fuel efficiency with Fuelwatch, a comprehensive fuel management approach.
How our engineers took an unsolvable problem and solved it.
You don’t need an advanced degree to understand the dilemma (although you may need one to try and tackle it). The conundrum is as follows: when a diesel engine combusts fuel, it produces NOx, a pollutant. It also puts out some soot. If an engineer designs an extremely efficient engine that produces little soot, that same engine (unfortunately) will produce even more NOx.
Where there once were two pollutants, there are now nearly zero.
Here’s where our SCR solution really shines. We created an unusually efficient engine, which provides the obvious benefits of fuel efficiency and low particulate emissions. To combat the resultant NOx emissions, our system injects Diesel Exhaust Fluid (DEF) downstream from the DPF. The exhaust gas and the DEF enter a catalytic converter, which turns the NOx into harmless nitrogen gas and water vapor.
DEF will be everywhere drivers are.
The DEF is fed into the system from an on-board tank that is simple to fill. Over 2500 Volvo Truck Dealers, truck stops, and other locations in North America will offer DEF, and the number is growing every day. A driver can travel from the West Coast to the East Coast and halfway back on a single tank of DEF, passing scores of DEF locations in the meantime.
SCR together with the “No Regen Engine”: A win-win.
This new system is the only one that meets the EPA’s near-zero NOx emissions requirement while at the same time relieving the driver from ever having to worry about active regeneration in normal highway operations. It all happens seamlessly.

