Okay, I know I'm not the only one who's had this deep, dark thought since the announcement that aqueous urea would be one of primary means of diesel exhaust after-treatment. Many U.S.-spec diesels from the 2009 model year onward, will be equipped with an onboard auxiliary urea reservoir which will constantly inject a small amount of urea into the exhaust stream to reduce NOX emissions.

The onboard tank would have to be periodically topped off at regular intervals to ensure proper function of the emissions treatment system. Supposedly, this currently hard-to-find fluid will miraculously be available at all auto-parts stores, gas stations, supermarkets and everywhere else once clean diesels start going on sale in large numbers. Perhaps that's true. But if it's not, and all of a sudden the "SCR Fluid Low" light starts coming on in the middle of West Texas, rural Nevada, or some similarly isolated locale, what's one to do?

Well, I know some ingenious (or stupid, choose your adjective) Bubbas would probably say, "Shoot, pee is mostly urea. Why can't we just pee in the tank?" Well, maybe in absolute emergency situations, it might get the job done, I'm sure it's probably the last thing engineers would recommend, and might cause some other long-term problems if done on a repeated basis.

Thus, my prediction is that this sticker, or some variation thereof, will become commonplace on the new generation of diesels employing SCR Urea catalysts. I'm not trying to be vulgar here, just matter-of-fact. What are your thoughts?