I agree that it's kind of dumb. The EPA along with other on-road regulatory agencies do some funny stuff from time to time. I know they get feedback from the industry on law proposals but who knows what other kind of crazy shit they were asking for when this got left on the table. 0.2 NOx is pretty ridiculous…

I had similar thoughts but that's one of the first pictures that comes up when you search "DEF gauge."

Now that sounds like a serious problem.

It's the warning light for the DEF (diesel exhaust fluid, yes, that's a real thing) system. Usually the light will come on when the urea tank is low. Most passenger cars the tank is sized to be refilled at the oil change interval. In the heavy truck industry, you usually have an option of what size tank you can get so…

Hey! No cheating. jk, that's right though.

I'm liking these potential theories on what this light means.

Still bummed that this didn't make the list.

I would say that it blows as a power source.

How was I supposed to know you're lactose intolerant?

Yeah, I realized that after I submitted it. I attempted to edit but Kinja thwarted my efforts to change it to "emissions equipment."

Yeah, considering that F-150 sales were almost as much as Toyota Corolla AND Camry in 2011, I think it says a lot about the US light truck market. I assume these are consumer vehicles and doesn't include class 4 and heavier vehicles.

They can't hear when anyone speaks because their tinfoil hat is blocking the brain corrupting sound waves. (I.e. logical arguments)

Ah, the joys of being a niche carmaker.

Those are people that clearly have no idea how the auto industry works.

I found the table that showed weight and the fact that the big 3 have a corporate average weight of over 4200lbs. While the top 3 in mpg are around 3300lbs.

Sure they can touch but then the plane needs to be repaired afterward. How do I know? Because I worked in repair design office in aircraft and we saw this happen. Although the one I worked on specifically had one of the landing gear collapse.

Most vehicles run fine without emissions. This is a government mandate.

Do you mean refill it? DEF is a consumable so I don't know why you'd be changing it. It's like changing your washer fluid. Some OEMs recommend flushing the tank from time to time but that's all I've heard of.

Yes, I've seen it happen. People do this all the time in Chicago (blocking and passing on the shoulder).

DEF (diesel exhaust fluid) system warning. Yes, this is actually a thing. They spray urea into the exhaust to react with NOx gas.