When most of us picture the high-tech personal mobility of the future, we tend to imagine a sleek, dead-quiet electric car, packed with voice- or motion-directed gizmos and self-driving features. We see ourselves gliding around almost effortlessly, free to talk, work or text as we see fit.

What few of us conjure up is having this sort of experience in a gasoline-fueled car. But that may be changing in the face of recent design advances. The internal combustion engine—the workhorse of the industrial age—is proving to be much...