New rules on replenishment of diesel exhaust fluid (DEF) will allow vehicle manufacturers more leeway in equipping trucks with DEF tanks without certifying them individually, according to the Environmental Protection Agency.
As reported by Heavy Duty Trucking, one practical outcome of the rule is that trucks might get smaller DEF tanks.
Truck owners and drivers are not directly affected by the new rules, but must continue to maintain vehicles as before and ensure they work properly.
DEF is required in new model selective catalytic reduction (SCR) diesel engines which reduce nitrogen oxide through a chemical reaction.
The new rules reflect EPA’s greater confidence in availability of the special fluid, reports HDT. DEF is much more widely available today than it was four years ago, so not as much of it needs to be carried aboard the vehicle.
The new rules set tank-size “ratios” of DEF to fuel, which builders can use for any vehicle. This will give manufacturers “more flexibility” in choosing tank sizes than before, an EPA source told HDT.