Putting diesel in a petrol car is a little rarer than vice versa, but it can still happen. Here’s what happens when you do ...

Diesel used to be a big deal. A couple of decades ago, some governmental authorities and plenty of automakers thought that, one day, we’d all be driving diesel vehicles fueled by sustainable biofuel.

Just a decade ago, diesel cars outsold gas cars in Europe. Super-efficient and great for long-distance cruising, diesel cars seemed headed toward a very bright future. Heck, there is still no vehicle ...