When I was growing up, diesel was always considered the greener option than petrol, and this was reflected in the prices, diesel always cost less because it was taxed at a lower rate.
Now they say it’s worse than petrol and prices are now higher for diesel.
So what changed, or what did we suddenly learn about diesel that we didn’t know before?
Bonus question, considering they’re both made from crude oil, what’s the difference in how they’re refined?
In: Chemistry
Years of study eventually showed that some of the waste products of diesel burning were just as bad as those from petrol (gasoline) – it’s *never* been greener, we just used to think that it was. As we learn, the science changes. And it’s an oil derivative, so it’s never going to be exactly “green” anyway.
We also discovered that the NOx emissions were killing people and just basic “smoke/dust” (“particulate matter”) from burning it was far worse.
That meant more stringent controls. The EU EN590 standards, etc. really cracked down on what was allowed, which meant that diesels essentially became the same as or more expensive than other ICE vehicles. Diesel now has to give out 200 times less sulphur than in the 90’s, for example. Things like AdBlue came on the market to try to reduce emissions from burning diesel in vehicles.
And then we found that EVEN THOUGH we’d done all that, things like NOx weren’t dropping as much as we’d expect. It was at that point that we discovered that many car companies were literally just cheating the emissions tests and actually pumping out as much as they used to, but hiding it behind software trickery designed to detect if the vehicle was being tested for emissions or driven normally. They claimed that they basically couldn’t make a car with the performance they wanted if they didn’t give out those emissions.
That led to BILLIONS of dollars of lawsuits and recalls for many/most diesel manufacturers. That cost almost certainly is being recouped across the industry, not just diesels, but it also means diesels are under far more scrutiny now and thus costs are rising.
Diesel being greener was always a con, basically. We just didn’t know it for sure and people still bought them for decades thinking they were cleaner.
I can remember calling bullshit on this back in the early 90’s – my dad was a fleet mechanic for lorries, etc. and claimed (as he’d been told) that diesels were cleaner. It was always bollocks. By the 2000’s we knew it was a lie. Nowadays, people thinking that diesel is cleaner because of what they grew up with is still rife (as your question shows).
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