As a past owner (many years ago) of a Wankel-engine powered car I was entertained at the mention of "Wankel". Emissions were the least of its problems, reliabi

As a past owner (many years ago) of a Wankel-engine powered car I was entertained at the mention of "Wankel". Emissions were the least of its problems, reliability being far less than desirable, as in barely able to keep going at all. Later on there were more reliable rotary engines, e.g., Mazda. If memory serves, there were emission problems and the engine was eventually discontinued for that reason. Rotaries were an interesting idea, hypothetically better, but implementation was obviously difficult and ultimately a failure. In today's world, we need to stop burning fossil fuels and electric-powered vehicles look promising. I'm looking forward to advances that will make electric cars practical. Of course, burning coal or natural methane to make electricity wouldn't be ideal, though possibly more efficient than the distributed combustion we now use.