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
Diesel engines and gasoline engines operate using diffirent principles – you can almost think of it like different operating parameters. The diesel cycle is inherently more thermodynamically efficient than the Otto cycle (how gasoline engines operate). However, they burn less clean, essentially less of the fuel is spent during the process, and I believe the fuel is also less purified – what this translates to is there are more pollutants spit out in the exhaust. The Holy grail has always been to filter the exhaust enough that diesel cars were as clean burning as their gasoline counterparts. Car companies lead us to believe they achieved this. It turns out – they actually just managed trick the emissions tests, and they’re inherently as dirty as ever. If you clean them up – they end up being less fuel efficient, essentially the juice isn’t worth the squeeze. The result – the diesel boom deflated.
Latest Answers