The journey from the thundering hooves of horsepower to the silent hum of battery power is a fascinating tale of innovation, perseverance and environmental consciousness. The history of automotive engines is a chronicle of human brilliance and dexterity, tracing its roots back to the era of the horse-drawn carriage and propelling us into a future defined by sustainable mobility. Although electric vehicles seem to now be our future, did you know that some of the very earliest experiments with horseless carriages were battery-powered?

The term ‘horsepower’ has a literal origin. In the 18^th century, Scottish engineer James Watt sought a way to quantify the power of his steam engines in terms relatable to his contemporaries. Drawing inspiration from the common sight of horses turning mill wheels, Watt coined the term ‘horsepower’ to express the work a horse could do in a given time. This marked the birth of the horsepower unit, laying the foundation for the industrial revolution and the mechanisation of transportation.

As the 19^th century unfolded, inventors and engineers turned their attention to harnessing the power of internal combustion engines. The late 1800s witnessed the birth of the automobile, with pioneers like Carl Benz and Henry Ford ushering in a new era of personal mobility. The road of petrol engines became the soundtrack of the 20^th century as cars replaced horse-drawn carriages, transforming the world’s cities and landscapes.

Almost universally credited with creating the automobile, Carl Benz’s 1886 Benz Patent Motor Car was the blueprint for the vehicles that would dominate the 20^th century. Yet, decades before, electricity had already proved to be perfectly capable of doing the same job. In the 1830s, Scotland’s Robert Anderson invented a motorised carriage powered by galvanic cells, and around the time Benz’s machine was on the scene, another Scot, William Morrison, who lived in Iowa, USA, had developed a self-propelled carriage that could travel at the breakneck speed of 20 mph and cover 50 miles on a charge.

At the dawn of the automobile, there was another well-established rival to petrol power: steam. In the early 1900s, scaled-down versions of the engines that revolutionised the railways were also driving cars such as Stanley Steamers. Although more than 11,000 vapour-powered machines were built by the American Stanley brothers, ultimately, the need to fill up with both water and solid fuel, combined with the time they needed to heat up, meant the steamers were soon surpassed by the more practical internal combustion machines.

A huge step forward for the internal combustion engine came with the development of the electric starter motor, which, largely, rendered the traditional starting handle obsolete, meaning drivers could start their cars at the press of a switch instead of literally risking a limb cranking it into life. Ironically, this small electric motor heralded the rapid demise of full-electric cars, and they wouldn’t return to favour for the best part of a century.

Instead, development of the internal combustion engine continued at a pace. Benz’s first single-cylinder employed the four-stroke cycle, invented by Nicolaus Otto, Gottlieb Daimler and Wilhelm Maybach in 1876, but within three years the two-stroke engine had joined it as a viable power plant and in 1892, Rudolf Diesel added his eponymous engine to the mix.

Meanwhile, the number of cylinders containing the combustion rapidly rose. In 1889, Daimler had a V-Twin and a year later Maybach increased the count to four. A straight-six was fitted by the Netherlands’s Spyker in 1903, a V8 was developed in France in 1904, America’s Packard upped the ante to 12 cylinders in 1912 and by the 1930s Cadillac and others were up to 16 – all in the quest for more and more power.

Another way to gain more grunt was discovered very early on: forced induction. Gottlieb Daimler patented a gear-driven pump to boost airflow to his engines back in 1885 and supercharging gained popularity, especially in Bentley and Mercedes-Benz models of the 1920s and onwards. An alternative approach – to use an exhaust gas-driven compressor, more commonly known as a turbocharger – dates to 1905 but wasn’t seen as practical for production cars until 1962 when both the Oldsmobile Jetfire and Chevrolet Corvair Monza made their debuts.

There have been other attempts to reinvent the combustion engine along the way, tweaking the original “suck, squeeze, bang, blow” four-stroke Otto cycle or, even doing away with cylinders completely. The Atkinson cycle, named after British engineer James Atkinson, only found its niche 100 years after it was invented. Using variable stroke lengths, it can deliver improved power and efficiency at the expense of a little more mechanical complexity. The Miller cycle devised by Ralph Miller, allows the intake valve to remain open longer. When combined with forced induction it further increases the efficiency.

Japanese carmaker Mazda has perhaps been the most ambitious with its efforts to challenge the combustion status quo. In 1967 it launched the sporty Cosmo coupe powered by a rotary engine that was originally invented by German Felix Wankel. In lieu of pistons rising and falling in cylinders, the rotary engine has an oval combustion chamber with a near-triangular-shaped rotor at its centre. With fewer parts than a piston engine and, as the name suggests, a rotary movement, these engines are smooth and powerful but proved not to be particularly fuel efficient and early examples were plagued with reliability issues. Nonetheless, Mazda persevered and now uses the rotary as a range-extender in its MX-30 electric vehicle.

The Japanese manufacturer also turned its attention to the more conventional piston engine, hoping to combine the best features of diesel and petrol together in one package. Its Skyactiv-X Spark Controlled Compression Ignition engines use compression alone to ignite fuel at low rpm, for diesel-like efficiency, and spark ignition at higher engine speeds for power.

The Mazda3 Skyactiv-X is also a mild hybrid, so now’s a good time to talk about this relatively recent technology. It was Toyota, with its Prius, that first introduced the concept to the mass market in 1997. It used a combination of a petrol engine and a battery-powered electric motor, which meant that, at low speeds, and for short distances, it was zero-emissions capable. Other brands soon followed with their own takes on the tech and now even the latest Lamborghini Revuelto is a hybrid.

Today’s hybrids come in several guises. So-called ‘mild’ hybrids usually employ an integrated starter-generator to give a little extra boost when pulling away from a standstill. This improves efficiency and reduces emissions, but the combustion engine will need to run for the car to move. “Self-charging” hybrids (like the original Prius) tend to have larger batteries and a bigger electric motor so they can be driven a short distance on electric power. When the batteries are depleted regenerative braking and power from the engine are used to replenish them. “Plug-in” hybrids, as the name suggests, can be plugged in to charge their batteries, which tend to be bigger, allowing for longer distances to be covered without any tailpipe emissions, while for longer journeys the combustion engine kicks in.

For a true emissions-free drive, however, the answer is electric. While some car makers, such as Toyota, are experimenting with using hydrogen in combustion engines or electricity-generating fuel cells, by far the majority are focused on battery-electric vehicles.

The modern electric car had something of a false start. In 1996 General Motors revealed its EV1 – a sleek coupe that, in its original form with old-school lead-acid batteries could do 55 miles on a charge. Later updated with nickel-metal-hydride cells the range increased to over 100 miles. More than 1,000 were produced, but in a bizarre about-turn, GM abandoned the project, even going as far as buying back and destroying almost every example.

It would take an upstart to really put electric cars on the agenda. In 2008 a little-known American company took a most unlikely approach. Tesla made electric cars sexy with its first car, a high-performance Roadster, based on the Lotus Elise. Almost 2,500 Roadsters were sold around the world, paving the way for Tesla to introduce its Model S luxury saloon and prove that there was a demand for a new way of driving.

With more efficient lithium-ion batteries and hugely powerful electric motors, Tesla delivered extreme performance – on the road and in sales. The legacy brands stood up and took notice.

Now, as governments around the world are moving to mandate zero emissions for new cars from as early as 2030, battery electric vehicles are, once more, the future of motoring.

As we can see, the combustion engine’s success came at a cost – environmental pollution and a growing dependence on finite fossil fuels. The realisation that our reliance on gasoline and diesel engines was unsustainable prompted the shift towards exploring alternative, cleaner technologies – of which there have evidently been a few.

In recent decades, EVs have indeed emerged as a promising solution to the environmental challenges posed by traditional combustion engines. The development of efficient battery technology, coupled with a growing awareness of climate change, has fuelled the popularity of electric cars. Companies like Tesla have become synonymous with cutting-edge EV design, challenging the dominance of internal combustion engines, and driving the automotive industry towards a greener future.

While EVs offer a cleaner alternative, the transition from traditional engines to battery power is not without its challenges. Battery technology continues to evolve, addressing concerns related to range, charging infrastructure and the environmental impact of manufacturing batteries. Breakthroughs in materials science and engineering are gradually overcoming these hurdles, promising a future where EVs become more accessible and practical for the masses.

The history of automotive engines is a testament to humanity’s ability to adapt and innovate in the face of evolving challenges. From the clatter of hooves to the whirr of electric motors, each chapter in this story reflects our quest for efficiency, sustainability, and a better tomorrow. As we continue to explore new frontiers in automotive technology, the journey from horsepower to battery power represents not just a shift in transportation, but a transformative leap towards a cleaner, more sustainable automotive future.

Whether you are passionate about preserving the heritage of classic cars or looking ahead with new technologies, we here at HBPR appreciate the entirety of the automotive industry. We recognise that we wouldn’t be where we are today without the pioneers of the past, and we love crafting memorable motoring content and delivering insight for all our clients. If any of our content has resonated with you, you’d like any more information or just looking for an informal chat about the automotive industry or otherwise, please do get in touch at hannah@hannahburgesspr.com. Our door is always open.