[4wsn]

I know this is a popular take, but the blindspot is commercial engines.

> bypass emissions sensors on 630,000 RAM pickup truck engines

In this case, and in nearly _every report of a scandal_, the issue is with passenger vehicle engines, not commercial vehicle engines.

Diesel engines can be engineered to meet emissions requirements without cheating, they just aren't except for commercial use.

[fragmede]

Why is that? Are the parts necessary to meet emissions requirements extra expensive and so are only worth installing on commercial vehicles which are more expensive, vs passenger vehicles have a different profit margin, or is it something else, like commerical vehicles have lower standards for noise or higher standards for maintenance?

[4wsn]

A combination of factors; cost, customer expectations, and convenience.

It's easy to produce a lot of power, it's not easy to do so reliably and within emissions specs. That's where the cost comes in, and where customer expectations come in. If VW is going to be offering a 110 kW 2.0 liter engine, well, Mercedes-Benz can't come in and offer a 90 kW 2.0 liter engine just to meet specs. At the end of the day, margins are fairly thin and regulators are compliant. It's cheaper to just cheat the emissions than make the engine meet emissions specs.

The convenience factor is diesel exhaust fluid (AdBlue); the stuff really does work very well. However, dispensing it at the most effective rate in regards to emissions would mean it has to be topped up between service intervals; very inconvenient. Increasing the tank size is a non-starter because packaging space in modern vehicles is at a premium. So the dirty secret (at least for Mercedes-Benz, confirmed by one of their engineers) is that they calibrate it to last service intervals; not to meet emissions. It's only in rare cases where the owner has to refill the tank themselves.

In regards to the AdBlue situation, if you're in Europe where there are a lot of diesel passenger vehicles and also a lot of diesel trucks and buses, next time you're in the city or on the highway, pay attention to the characteristic diesel stink, either as a pedestrian or a driver. You're never going to smell it from a truck; it'll always be a passenger vehicle. :)

[dan12ha]

I’m in the UK. We have AdBlu pumps in the gas station. Just fill up fuel and AdBlu at the same time, it’s really easy.

[paradox460]

Here in the western US we have em too. Diesel bowsers have a second blue hose attached. You put one in the fuel port, one in the def port, and then let them both fill up

[archi42]

I think I've seen those pumps here in Germany as well, and I'm pretty sure you can get AdBlue in canisters (I have one in the basement that I forgot putting back into a rental).

Yes, this (plus that the whole thing is more convenient than filling up the washer fluid) makes the whole "we don't want the customer to fill it up" even more absurd.

[vuln]

Commercial diesel engines run for millions of miles / tens of thousands of hours versus passenger or non commercial is measured in hundreds of thousands of miles typically and thousands of hours. Commercials idle for far longer especially in dense areas like cities, rest stops, distribution centers and ports. Maintaining a fleet of diesels can be written off as a business expense (OPEX) while most non commercial use can’t or isn’t. Would be my guess.

[hattmall]

There's also no real competitive force. Gasoline isn't a viable alternative in most cases.

[SigmundA]

Not surprising, the commercial version of the ISB in question only goes up to 360hp rating, usually they run 300 or 340 hp. The commercial versions all have SCR (Urea Injection) along with DPF an EGR.

In the pickup it's rated 400 hp. I wouldn't be surprised if in the pursuit of HP / Torque to keep up with Ford and Chevy's diesels they cut corners on the emissions. The hotter you run diesel the more powerful it gets, the leaner the more efficient it gets, hot and lean makes NOx in the combustion chamber from oxygen and nitrogen, the more NOX the more SCR you need to reduce it back in the exhaust.