The Evolution of Engine Technology

For over 100 years we’ve used the combination of air, fuel, and spark to power cars, but the way that we bring these things together has evolved over several eras. In the early years, engines were oversized, underpowered, and crude compared to what we’re used to today.

For example, Cadillac’s 1930s V16, a 7.4 liter brick of inefficiency, produced less power than Honda’s current 1.5 liter 4 cylinder Civic engine. Just for perspective, that means that a relatively mediocre engine today requires one quarter the number of cylinders, and about 20% of the displacement to generate more power than the cream of the crop just 90 years ago. So, how did we go from the lumbering, inefficient lumps found in early cars to the smooth, efficient, and refined pieces of machinery under the hood of modern cars? Well, let’s find out.

(image credit: Engineering Explained YouTube Channel)

Two Eras: Pre- and Post- Fuel Injection

When we look at the big picture, we can break down combustion engines into two distinct eras: pre and post-fuel injection. Fuel injection ‘injects’ fuel into the combustion chamber of an engine. Without fuel injection, you need a carburetor to distribute fuel to the cylinders. Carburetors, as anyone who’s owned a car with one knows, were finicky, imprecise, and required constant attention and adjustment based on conditions like temperature and altitude. Carbureted engines were inefficient and underpowered.

Fuel injection, however, eliminated the need for carburetors by injecting fuel either into the intake manifold or, later, directly into the cylinders themselves. Cars ran more smoothly, operated more efficiently, and generated more power. The first car built with fuel injection was the 1955 Mercedes 300SL Gullwing, a legendary car and the quickest in the world at the time. The Corvette got fuel injection soon after, and thus started the era of fuel-injection, with carburetors slowly beginning to be phased out.

The dawn of Forced Induction

Turbo Rocket v8 (image credit:

As we explore major developments in engine technology, we would be remiss if we didn’t take a look at forced induction. Forced induction refers to the pairing of either a turbocharger or supercharger to an internal combustion engine. Turbochargers use exhaust gases to spin a turbine that compresses air into the cylinders, and a supercharger uses an engine-driven belt to do the same thing.

Both turbos and superchargers increase power, but turbochargers are especially useful for their ability to increase efficiency. Adding a turbo to an engine does not make it more efficient, but it does make it (and I’m speaking very generally here) more or as powerful as a bigger engine. So turbos provide big engine performance with little engine fuel economy, and that’s why just about every car nowadays has one.

The first turbocharged passenger car was the aptly (and awesomely) named Oldsmobile Jetfire, which came out in 1962. Since then turbochargers have come quite a long way, and they played a big role in moving away from the era of big V8s into the era of boosted 4-cylinders that we live in now.

Come on Help My Car Go, Mr. Roboto: Electronic Engine Control

Electric Control Unit (image source:

Please forgive me for that miserable pun in the title of this section. But also try singing it to the tune of Mr. Roboto, just to indulge me. It actually works pretty well, just like Electronic Engine Control! In the early days of the internal combustion engine, things like ignition timing and air fuel ratios were all controlled mechanically. Mechanical systems detected engine irregularities in certain parameters, and then adjusted things mechanically to remedy whatever needed to be remedied.

However, as you might expect, these systems were not very precise, and prone to error. So manufacturers and their engineers explored ways to computerize the control systems of engines, and this was a slow process that happened over many decades. For this reason, it’s difficult to pinpoint exactly when electronic engine control was introduced, though it became more mainstream in the 1980s.

However, many preceding small advances built up to our ability to control an engine totally electronically as we do today. The ability to control engine parameters electronically yielded a whole host of benefits—namely increased engine smoothness, easier operation, and better efficiency.

Final Thoughts, and a Brief Nod to Miscellaneous Advancements

As you know and can see here, the three aforementioned technological advancements represent the most significant steps to the engines that we know and love today. However, they do not paint the whole picture, as tens of thousands of smaller pieces of tech that also helped to refine internal combustion engines, transforming them into something unrecognizable compared to their earliest examples. Among many others, these advancements include things like variable valve timing, camshaft placement, and ignition system overhauls.

I won’t bore you with a comprehensive list of those smaller advancements (not to mention a list of this type would take months of research to compile completely), but know that the above three are the big leaps, helped along by thousands of other smaller ones. In combination, all of these things led to engines that are smooth, efficient, powerful and refined, adjectives that would be ill-fitted in their application to engines produced just a few decades ago. 

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