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Long Term Update 1: 2011 Chevrolet Silverado 2500HD


There is a new era of diesels in the United States, one that includes more power, cleaner emissions (lower measured amounts, no diesel smell, and next to no black smoke), and less noise than in the past. So when getting into the Silverado, it wasn't a surprise that there was no "oil-burner" smell. Without that well-known -- and now basically obsolete -- odor, it was surprising what scent was more prominent: that of the outgassing from the plastics in the cabin. The gases smelled exactly like a children's doll. Who knew that a heavy-duty truck interior could smell like a "Wets 'N Wiggles" baby doll? But after a couple of weeks, that smell subsided and the truck's interior developed a much more masculine odor -- not sweat and old socks, mind you; a lot more neutral smell, without the kid's toy aroma.

One day, while stopped at a red light, I noticed that the truck sounded like it was revving a little high. I looked down at the tachometer to see what was going on, and the needle was at a whopping 800 rpm. This truck exhibits the same low-rpm range as every other diesel out there (by design), and that was a little higher than usual. When it came down again, the tach read 650. This brings up the first big questions I have about the CHEVROLET SILVERADO HD: what happens when the emissions system burns off the particulates it collected? Was that was I had heard and saw? When a diesel truck with the Selective Catalyst Reduction system (urea and purified water are injected into the exhaust to dramatically reduce what comes out of the tailpipe) is at work, should there be indicator that burn off is happening? Or, if it happens behind the scenes and there's no need for the driver to know about it, should it just happen when it happens? I've heard that the ideal time for burn off to happen is out on the highway, driving at a steady speed. If that's true, I wonder if future versions of the SCR system would allow drivers to cause the burn off to happen.

It could be that the driver would know when he or she is going to be out on the road, and can start a burn off; not prompting it could have the burn off happen as it always would, based on how full the diesel particulate filter gets. And what happens if the system is in the middle of burning off this excess soot/particulates, and you shut off the engine after parking? Does it start the process again when the engine is back up to temperature? These are all things I'm going to look into over the next several months.
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