Hacker News Reader

Comment by kmeisthax | Hacker News Reader

No, none of the lockouts were actually intended to prevent farmers from rolling coal in their tractors. Also, I'm not sure why a farmer would want to roll coal. But since rolling coal is a thing that people occasionally do, it's a useful boogeyman.

Serialized parts don't prevent you from defeating emissions controls anyway - there's plenty of low-tech ways to tamper with sensors to do the same thing. Even the theft prevention[0] benefits are limited, because the chip with the serial codes on it can be desoldered and resoldered onto a new board.

[0] i.e. if someone were to chop-shop your phone or tractor. It happens.

View on HN

Removing the emissions controls on diesel engines (EGR and DPF specifically) can actually give a significant boost to fuel economy. At the cost of higher emissions of particulates and nitrogen oxides. Diesel engines recirculate the exhaust gas for cooler combustion (though less thermodynamically efficient, this reduces nitrogen oxide formation). They also come with particulate filters on the exhaust, which both increase pumping losses and require extra fuel to periodically regenerate the filter (basically burning off the soot particles that were collected, which needs extra heat which takes some fuel).

There are reliability improvements to be had as well, reducing operating costs still further (the emissions equipment can get clogged up, especially if the engine isn't running perfectly).

So yeah, farmers (all commercial diesel users really) have a strong financial incentive to avoid or remove these emissions controls, provided they don't get caught of course.

Thanks for the explanation. I did not know rolling coal was a thing. But it clearly looks like a boogeyman

Roll coal? Would that be a dangerous term to search for, or should I play ignoramus and ask here?

A practice typically done by rednecks with their diesel pickup trucks, tweaking the ECU and fuel profiles run the engine overly rich so the exhaust billows out thick black clouds (thus, "rolling coal"), particularly when they rev the engine.

Disgusting. I just watched some videos and it seems to be mostly used as a soft attack on bicyclists, environmentalists, pedestrians, people on the left etc. Some “anti-environmentalists” were literally sticking their face right next to the exhaust while it was rolling coal to make a point lol. That’ll show them.

It's usually done as a form of protest, and in the same way as a horn, not continuously.

Perfectly SFW example here: https://www.youtube.com/watch?v=Y2G44D7_p50

Looks like the Reaver ships in Firefly.

Reply on news.ycombinator.com