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Comment by BashiBazouk | Hacker News Reader

The 4 cylinder TDI was for the economy range of vehicles. The more expensive models with bigger engines use urea tanks or BlueTec as Mercedes Benz politely calls it. More expensive to make and service, but those who buy more expensive vehicles expect these kind of added service costs. Those on the lower end do not.

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I've driven several pickups that require diesel exhaust fluid. It's really not a big deal. If you don't want to pay $3/g for it at Walmart then go to a truck stop where you can get it from a pump for slightly less.

I know someone who recently bought a sportwagen with the urea system. They said it was a $300 service once a year to refill the tank. Though you are probably right that it can be done much cheaper yourself.

It's an ISO-specified solution of CO(NH2)2 and deionized water. If evil automakers want to screw the consumer they could make the fill port difficult to access, but other than that it seems straightforward. The "once a year" thing is also strange, since DEF usage is totally dependent on miles driven and how "hard" those miles were. (High-RPM, high-turbo-pressure driving uses more than low-RPM, low-turbo-pressure driving.)

Mercedes did this on the GLK - the fill port requires a special nozzle. So you buy one of their refill bottles, cut the bottom off, and use it as a funnel with your DEF of choice (since it's a standard ISO solution).

Fun fact: the fill nozzle at the truck stop is also standardized by ISO, so that it will fit all ISO-compliant "commercial vehicles and buses... having a gross vehicle mass of more than 3,5 t". I wonder how how much lobbying it took to convince ISO not to specify anything for smaller vehicles?

Some of the truck stops have DEF nozzles that require a magnet to operate, so the truck drivers don't put it into their diesel tank. There are adapters you can buy that will allow you to fill up your diesel-powered car or RV using the cheaper bulk pump.

That's crazy. I think I probably paid $20 for DEF to cover the ~11,000 miles I drove in my truck last year (and I'd have to imagine it's thirstier than an economy car).

You pop a blue cap under the hood, dump in the DEF, and you're done. RAM and Ford (starting this year I think?) make it even easier by putting the fill behind the fuel door right next to the fuel cap.

5 gallons seems to last me about ~5,000 miles.

DEF only became required in US light-trucks ("1-ton" and below) for the 2015 Model-Year I think.

Anyways, the fluid itself is about the same price as gasoline. A $300 service is just plain gouging.

>The 4 cylinder TDI was for the economy range of vehicles

I have a 2014 Jetta TDI (4 cyl) with urea injection. I'm totally confused by the information surrounding what cars are affected.

Model year vs production/purchase year probably doesn't help.

As far as I understood, "model year 2015" cars (made/sold in 2014) are unaffected as of yet, because of the urea injection.

I'm guessing that the cars with urea injection will be fine. It will be tested by the EPA and CARB if you are in California to make sure. Since the urea injection is there specifically to deal with the pollution this issue is causing, the only cheat I would imagine would be to lengthen the amount of time to change the urea tank and if that is the case, VW will be required to cover the added service costs.

Not so sure myself, check-out page 63:

http://www.theicct.org/use-emissions-testing-light-duty-dies...

Car B was a 4cy VW diesel with urea from last year.

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