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Click above for a high-res gallery of the MB GL320 BlueTEC

Owners of the new crop of clean diesels will have another maintenance item to concern themselves with if their new cars are equipped with urea injection. The EPA requires that all diesels meet strict new emissions standards, which almost always requires the use of either a NOx trap or urea injection. To ensure that the system is working, a sensor checks both the level and the quality of the urea solution and will keep the car from starting if the tank is empty. The new VW Jetta TDI doesn't use urea, but the new Mercedes-Benz BlueTEC vehicles do. According to Mercedes, a counter will appear on the dash when there are twenty starts remaining. If the driver ignores the message, the car will not operate until at least two gallons of urea solution is added to the tamper-proof tank that resides in the spare tire well.

Engineers have designed the urea tanks to be large enough to last about 15,000 miles. This should be large enough that drivers never run out, as the tanks will be checked at every schedules service. As an alternative, small bottles of the urea solution will be available for owners who want to maintain the system themselves. The cost of the urea solution, which MB refers to as AdBlue, will mirror the cost of diesel fuel, so a refill shouldn't cost more than $30 or so. Before anybody asks, yes - urea is a component of urine, and no - peeing in the tank will not fool the sensors. You've been warned.


[Source: Automotive News - sub. req'd]


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    • 1 Second Ago
  • 37 Comments
      • 6 Years Ago
      "at least two gallons of urea solution is added to the tamper-proof tank that resides in the spare tire well"

      Tamper-proof? Is that a challenge?
        • 6 Years Ago
        Yeah, basically they just removed any and all sense of security of that tank. It will be cracked by the end of the week if not sooner. I'll bet the seams degrade when pissed on.
      • 6 Years Ago
      The comment section on these stories about urea really give you a snapshot of the mental age of the different commenters. It couldn't be any clearer even with a bar graph.

      If you ever find yourself trading endless comments with someone regarding pushrods vs. DOHC or how many Mustang variants there need to be and you wondered who the person behind the name was, just check their comments on a urea related story. You might just be arguing with a 7th grader.

      P.S. - BOOGERS!!!!
        • 6 Years Ago
        7th grader? Hey, I resemble that statement, and my wife agrees with you. Enjoy life.
      • 6 Years Ago
      Didn't Honda's diesel pass emissions requirements without the urea usage in the EU? It would seem to be a good selling point to not have that added worry.
        • 6 Years Ago
        Additionally, the EU standards are not as strict. So, not many diesel vehicles there would require urea injection anyhow.

        But, yes LS2LS7 is right, urea is really only needed on larger engines, smaller ones can get by with a NOx trap generally.
      • 6 Years Ago
      Just pull to the side of the road and peee into it.
        • 6 Years Ago
        You people are aware, right, that urea is not urine? That urea isn't even obtained from urine, that it's synthesized in a lab? That urea solution doesn't smell, look, or work like piss? That you're making your lack of education as abysmally obvious as your stunted maturity?

        Just checking. Because to those of us who survived to about age 25, and paid attention in school, you sound like a moron.
        • 6 Years Ago
        I don't know about you, but I can't piss out 2 gallons on a whim.
        • 6 Years Ago
        Or maybe, and I'm going to blow your mind, here, Snark, some of us are kidding and like the simple pleasure of a joke about bodily functions. That, and--again, blowing your mind--you have no sense of humor.
        • 6 Years Ago
        @ Gag

        Your "unit" has nothing to do with storage capacity, so unless you have a bladder the size of a beach ball I'm still calling BS.
        • 6 Years Ago
        ...mine comes in a sparkling Martinelli bottle. ;)
        • 6 Years Ago
        @Snark
        Urea isn't urine but in theory you could attempt to make your own AdBlue solution in a pinch if you had a lot of pee. A human being's daily pee can have up to approximately 35 grams of solid urea in it (although usually it's less than this). So if you've held in your pee for the whole day on a long road trip you might have enough urea to make almost 100cc's of this solution or a 1/10th of a bottle. It's just made up of distilled water and urea (approximately 2 parts water and one part urea by weight). Really, if you have an entire car full of people who haven't peed all day, and you ran out of urea in the middle of nowhere (I doubt AdBlue is going to be easy to get when there aren't dealers nearby), you could probably make your own pee version of it. You'd just need to get something to boil pee in and a few bottles of isopropyl alcohol and distilled water, then boil off your pee until it's thick and syrupy, add the alcohol, boil it down again (making sure not to set yourself or your car mates on fire while doing this since it's super flammable, so have a chemical fire extinguisher ready), add distilled water water, boil it down again-you might have to repeat this a few times to separate out the urea, but finally you should be able to crystallize off somewhat pure urea (this is not the most efficient way to get urea at all but probably the only way you can do it with stuff you can buy anywhere). It'll look like a bunch of crystals sitting in an oily yellow goop at this point, and you can grab a coffee filter and pour this goop onto it. The other stuff should filter through leave the urea crystals on the top. You can probably repurify these crystals by again dissolving only these crystals in distilled water or alcohol and boiling it down and letting it crystallize then refiltering. Then just dissolve the crystals in distilled water equivalent to 2x the weight, and voila-ghetto AdBlue solution.

        Of course, since this all takes an obscene amount of time you'd probably end up holed up in some motel boiling your pee in alcohol when the cops kick down the door thinking you're a meth dealer, lol.
        • 6 Years Ago
        @ Yar, well i don't like to brag but you know......you know....two gallons is not a problem for me seeing as my unit is ..............
      • 6 Years Ago
      Great so now people are going to be pissed because they are stuck some where because they are out of piss. What has the world come too?
      • 6 Years Ago
      chances are the urea tank only has a level sensor that feeds the ECU with info. So if your stuck just fill it with water! the ECU will just read a level and it will indicate that it is full.

      But you wont be emmisisons compliant!
        • 6 Years Ago
        eh, they'll probably use something a little more complicated, maybe measure the resistance of the solution or some other electrical property.
      • 6 Years Ago
      "the car will not operate until at least two gallons of urea solution is added to the tamper-proof tank that resides in the spare tire well."
      Thats funny. I've never heard of a tamper proof anything. The best part is they tell you where the tank is too.
      • 6 Years Ago
      Haha what a great note to leave the office on. More pee-jokes than i can shake a..... never mind.
      • 6 Years Ago
      Hmm, makes me wonder what people will do with the fuel tank runs dry? Pee in there, too?

      Seriously, we already have one tank that has to be filled up every 250-600 miles anyways. Forget to fill that one and it WILL leave you on the side of the road with no recourse but to put more fluid in it. If the urea lasts 15,000 miles, I really don't see the hangup here. Just top it off with each oil change. That gives you four opportunities to forget with no consequences...
        • 6 Years Ago
        And you'd win, too.
        • 6 Years Ago
        So the 20 start warning light meant nothing to you?

        Not to mention that as was mentioned above, you'd likely have changed the oil at least a couple of times over the ensuing 15K miles as well. Assuming a competent mechanic(if not the dealer) would check the level or at least offer to fill it. if not, sue them, not the manufacturer, they would be the liable party int hat case.

        But, there is definitely plenty of time there to check the level and fill it up. Especially if it seems you are planning a trip to a remote area.

        If you'd choose to sue after all of those warning signs and opportunities, I'd put that on the same level as those who sue McDonald's for making them fat.
        • 6 Years Ago
        What utter nonsense. I don't think you recognize the magnitude of this. If this tank runs dry, the vehicle will refuse to start next time you turn the key.

        So if you run out after it warns you 20 times, and you then stop on the side of the road in the desert a million miles from nowhere and turn the car off, THE CAR WILL REFUSE TO START.

        If this happened to me, I'd sue.
      • 6 Years Ago
      So why is everyone making sad, angry, dissapointed , funny comments....lets be honest none of us are gonna buy a Bluetec Benz.
      • 6 Years Ago
      I'd pee in it even if MB said I shouldnt.
      • 6 Years Ago
      Looks like I'm going to have to keep a bottle of urea, along with my usual bottle of oil, washer fluid, and antifreeze that stays in the trunk. Not a big deal, but annoying none the less.

      Either that, or I'll wait until someone finds a way around it. :-/
        • 6 Years Ago
        Do you already keep a separate bucket for emptying the water separator on ur TDI? No? Because that's done during servicing? oh. then why keep this bottle around if you/your mechanic are going to be doing at at service intervals? Unless you typically run your new car until ever last quart of oil has dried up.

        oh and PEE!
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