>I remember my mechanic friend 30 years ago saying that Diesel was not cleaner than petrol and this whole thing would end badly.
Well, that's obviously a complicated topic, but if you use biodiesel, isn't it infinitely better than gasoline, being carbon-neutral?
>diesel fuel gels in cold weather while gasoline stays liquid
Don't modern cars have battery-powered heaters?
What about this argument that because compression ratios are higher in diesel, the materials must be sturdier to withstand it, therefore it ends up being more durable overall?
It is true. I'm a noob but it seems like basically the diesel compresses the air in the cylinder a lot as part of its stroke. This increases temperature enough for oil to ignite. Because it's a purely temperature based effect (rather than a spark) even relatively dirty fuel oils will work. In fact, the diesel oil you buy at the gas station is just an artificial uber oil made by mixing petroleum components.
Dirty oils however have slightly worse mileage (10-20% so not really a big deal) and clog up the filter more. Otherwise yes you can put pretty much any oil in there, even leftover fry grease from McDs. It's the same thing as the "intended" diesel fuel, just slightly lower quality. If you mix shit oil with good diesel you just get medium quality fuel that's half as bad as the oil.