ORLANDO, Fla. — At a press conference held to introduce its new lineup of 2010 BlueTec engines, Detroit Diesel used the opportunity to counter what it says is misinformation floating around about the selective catalytic reduction (SCR) technology it and other OEMs are using to meet upcoming emission regs.

One mistake many have made in the past is that the diesel exhaust fluid (DEF) required for SCR engines is not, in fact, urea, the engine maker explained at the annual Technology and Maintenance Council meeting in Orlando. 

The two are not quite interchangeable as the latter is only a raw material component of the DEF spec used in 2010 SCR engines.

Be sure to pick up the current February print issue of Today’s Trucking for a feature that explains everything you need to know about DEF, but basically the fluid reacts with smog-forming nitrogen oxide (NOx) in an SCR catalyst, turning that NOx into safe nitrogen and water at the tail end of the pipe.

Bulk dispensers at fleets’ home depots will be
a popular choice for DEF fill ups at the start of 2010.

Among the myths that Detroit fought to counter is the notion that DEF is toxic. In fact, the company assures, it’s not toxic at any temperature.

And while it will freeze at something like 11 degrees F, immersion heaters in the DEF tank will prevent that. It will warm up quickly anyway, and the EPA is not concerned about this short delay since NOx is mainly produced at high combustion temperatures not seen in cold starts.

Nor is DEF as expensive as some have claimed. Mark Lampert, senior sales vice president at Daimler Trucks North America, allowed that, "we can’t predict what prices will be for DEF, or even diesel fuel.” But he said there have been wild exaggerations about pricing, including one claim of $19 per gallon uttered by one OE rep during the show.

Currently, DEF can be had for about $3 a gallon in bulk and about $7 for a half-gallon jug purchased at a car parts store, usually not know for price cutting.

Historically, urea and DEF alike have been somewhat volatile in pricing terms. There’s general agreement, however, that it will always be manageable, as it has been in Europe, where 500,000 trucks are running with SCR emissions-control systems without any issues.

Dave Siler, marketing chief at Detroit Diesel, explains that heavy Freightliner and Western Star trucks with 2010 Detroit engines will have 23-gal DEF tanks, good for 5000 to 7000 miles between fills. Two smaller versions will be used in smaller trucks, one as small as 6 gal. There’s no real likelihood of fitting larger tanks at this point.