Why components matter
Much writing about the car focuses on who built the first one. This article takes a different approach: it follows individual parts and systems that made cars easier to start, stop and survive in. Dates here are the commonly cited ones, and several inventions were developed by more than one person at roughly the same time, so treat any single “first” with caution.
Starting and ignition
Early gasoline engines were started by hand with a crank, and they used hot-tube or battery-and-coil ignition that could be temperamental. A major step was the high-voltage magneto, a small generator that supplied the spark without a battery. Robert Bosch’s company, with engineer Gottlob Honold, developed a widely used version around 1902.
Hand cranking was tiring and could injure the driver if the engine kicked back. Charles Kettering developed an electric self-starter, and Cadillac offered it on its 1912 models. Combined with a generator and a lead-acid battery, it made cars practical for people who could not or would not crank an engine, and it is often cited as one reason cars became more popular with women drivers. Later systems replaced mechanical contact points with electronic ignition, and today’s small electric motors in starters rely on the same basic idea.
Fuel and engine management
For decades, a carburetor mixed air and fuel. Wilhelm Maybach designed an influential spray carburetor in the 1890s. Engines of the 1920s began to suffer from knocking, an uncontrolled combustion that limits compression and power. Adding tetraethyl lead to gasoline reduced knocking and was widely used for decades, but it was later phased out because of its health and environmental effects.
Fuel injection existed earlier in aircraft and diesel engines, and electronically controlled fuel injection spread through passenger cars in the 1980s and 1990s, replacing carburetors. These systems depend on silicon chips and sensors, and later engine controllers also helped meet emissions rules.
Tires and wheels
Dunlop developed practical pneumatic tires for bicycles in the late 1880s, and the Michelin brothers used air-filled tires on a car in a French race in 1895. Compared with solid rubber, they greatly improved comfort and traction. The long-lasting rubber used in tires depended on earlier work on vulcanized rubber. Tubeless and radial tires followed in the twentieth century and improved durability and handling.
Brakes
Early cars used simple mechanical brakes, often acting on the transmission or the rear wheels only. Louis Renault is credited with an early drum brake patent in 1902, a design that enclosed the friction surfaces. Hydraulic brakes, which use fluid to transmit force from the pedal to all four wheels, were developed in the early 1920s, and Duesenberg offered them in 1921. Disc brakes, which resist overheating better, were used on racing cars in the early 1950s and on production cars soon after.
Anti-lock braking systems, which keep wheels from locking when the driver brakes hard, reached production cars in 1978 on some Mercedes-Benz models using a Bosch system. They were common on new vehicles by the 1990s and 2000s.
Safety equipment
Safety features arrived slowly, often after public pressure. Laminated safety glass, patented in France in 1903 by Édouard Bénédictus, began to appear in car windshields in the 1920s and 1930s. Béla Barényi, working at Mercedes-Benz, proposed the idea of a crumple zone in a patent in the early 1950s, in which the front and rear structures absorb crash energy while the passenger cell stays rigid.
The three-point seat belt was developed by Nils Bohlin at Volvo and introduced in 1959. The company then made the patent widely available. Airbags were patented in the 1950s, but systems became commercial options on some cars only in the 1970s and 1980s, and laws in different countries gradually required them. In the United States, the National Traffic and Motor Vehicle Safety Act of 1966 marked a shift toward federal safety standards.
Studies of these devices consistently show benefits, but no safety feature makes driving risk-free, and outcomes in any single crash are uncertain.
Emissions, electronics and electrification
In the 1970s, catalytic converters appeared on cars in the United States to reduce exhaust pollutants. Since then, microprocessors have taken over many tasks: controlling the engine, monitoring stability, handling navigation and assisting the driver. Meanwhile, lithium-ion batteries have made battery-electric and hybrid designs more practical, linking today’s cars back to the electric cars of the early 1900s.
The pattern
The modern car is the sum of a long list of small improvements. Starters and brakes made cars easier to use, safety equipment reduced injuries, and electronics made engines cleaner and more efficient. None of these changes was dramatic on its own, but together they separate the vehicles of the 1900s from those of today.