I agree that energy density is huge hurdle to over come. More so in aviation than ground vehicles but a problem none the less. It just wasn’t clear to me if you were implying that the modern automotive ICE was setting some kind of bar for cleanliness and efficiency compared to anything other than a non-modern automotive engine. But I think we are on the same page.
Originally Posted by MRR
The problem with electric motors is not that they cannot produce plenty of power and torque but that battery technology has not even come close to the energy density of liquid fuels. They don't necessarily have to reach this though because they are much more efficient to begin with but battery technology still has ways to go. Until this happens ICE vehicles will still be needed
"In theory, theory and practice are the same. In practice, they are not."