What if the internal combustion engine had gone differently?

A compact engine that burns liquid fuel in its own cylinders, light enough to carry itself.

If it had gone differently: Transport stays horse-drawn or rail-bound; there is no car, no truck, no aircraft engine, no 20th-century sprawl.

1. 1903Powered flight, Heavier-than-air flight stays a fairground stunt for another generation; the world shrinks more slowly.
2. 1908The Ford Model T, The car stays a rich man's toy; there is no mass motoring, no suburb, no roadside America.
3. 1913The moving assembly line, Cars, appliances and machines stay hand-built and expensive; there is no mass consumer economy.