From the Tokyo auto show comes confirmation that Honda’s 2.2-liter diesel engine will come to the U.S. installed in the 2009 Accord. The aluminum engine is fairly conventional in that it has a balance shaft, dual overhead cams, and high fuel pressure. The redline should be around 4500 rpm; that’s where the Euro-spec diesel Accord we drove topped out.
Power and boost levels have not been specified yet, but we can expect at least 150 horsepower and 260 pound-feet of torque. Honda engineers say the diesel is about 44 pounds heavier than a similar gas engine, but they wouldn’t confirm the actual weight of either.
One interesting tidbit is the cast stainless-steel exhaust manifold, but the most compelling story here is the NOx converter. There are two substrate layers on the converter’s honeycomb matrix: an outer layer that stores NOx and a lower layer of platinum particles that, although it also stores a little NOx, mostly reacts with the exhaust to produce ammonia during rich combustion. The ammonia, which is described by the formula NH3, reacts with the stored NOx to produce nitrogen and water. The process is choreographed by the ECU.
Honda claims its system was developed in-house and that, unlike VW’s similar NOx trap that will be for sale soon, Honda’s is scalable to larger vehicles. In other words, Honda says it believes it can put a V-6 diesel in a Pilot or similarly sized vehicle that meets 50-state emissions without having to inject urea, as will be the case with the VW Touareg diesel. Three different engineers repeated these claims; that gives us the feeling that such a vehicle is in the works.
