Have you ever wondered to yourself what the difference is between old and new car engines? As with any technology, there has been a gradual improvement in efficiency and complexity, as you'd expect. As it turns out quite a lot.
Despite the basic concept remaining relatively unchanged, modern cars have undergone a series of many little improvements over time. In the following article, we'll focus on 4 interesting examples.
Let's take a look under the hoods of time, shall we?
If it ain't broke, don't fix it
The basic principles of the very first cars are still used today. One of the main differences is that modern cars are the result of a pressure to improve the power of engines and ultimately fuel efficiency. In part, this has been market pressure from consumers as well as larger market forces.
It might be useful to think of the analogy between a wolf and a dog. They share the same heritage, have similar characteristics but one would have a tough time in a modern suburb, while the other would flourish.
Before we begin we'll give a brief overview of how an internal combustion engine functions.
An internal combustion engine, in essence, takes a fuel source, like gasoline, mixes it with air, compresses it and ignites it. This causes a series of small explosions that, in turn, drive set of pistons up and down. These pistons are attached to a crankshaft that translates the reciprocating linear motion of the pistons into rotational movement by turning the crankshaft. The crankshaft, in turn, transfers this motion through the transmission, which transmits the power to the wheels of the car. Simple right?
Well, it is a lot more complicated than that, as you'd expect.
Here's a simple explanation of the basics:
Interestingly, the conversion of reciprocating force into rotational force is nothing new. A very early steam engine was devised by Hero of Alexandria in the 1st-Century AD (pictured above).
Even older crankshaft devices are thought to have originated during the Han Dynasty, China.
1. Modern engines are more efficient
Burning fuel, like gasoline, isn't particularly efficient. Of all the potential chemical energy in it, around 14-30% is converted into energy that actually moves the car. The rest is lost to idling, parasitic losses, heat, and friction.
Modern engines have moved a long way to tease out as much energy as possible from the fuel. Direct injection technology, for example, does not pre-mix the fuel and air before reaching the cylinder, like older engines. Rather, fuel is directly injected into the cylinders, This gives about a 1% improvement.
Turbochargers use exhaust gas to power a turbine that pushes extra air (meaning more oxygen) into the cylinders to further increase efficiency by up to 8%. Variable valve timing and cylinder deactivation further improve efficiency by only allowing the engine to use as much fuel as it actually needs.
2. Ultimate Power
As Jeremy Clarkson once said, "It's all about MPG than MPH nowadays" or maybe it wasn't him.
Modern cars better fuel efficiency, they are also a lot more powerful.
For instance, A 1983 Chevrolet Malibu had a 3.8-liter V-6 engine could spew out 110 horsepower. By comparison, the 2005 version had a 2.2-liter inline four cylinder generating 144 horsepower. Not too shabby.
3. Size is everything, or is it?
This drive, no pun intended, for better efficiency in engines has also shrunk their size over time. This is not a coincidence. Car manufacturers have learned that you don't need to make something bigger to make it more powerful.
All you need to do is make the object work smarter. The same technology that has made engines more efficient has had the side effect of making them smaller.
Ford F-series trucks are a great example. The F-150 had two versions in 2011. A 3.5-liter V-6 engine that generates 365 horsepower and a 5.0-liter V-8 that generates 360 horsepower.
Ok, you might say, but wasn't there a 6.2-liter V-8 that generated 411 horsepower? Why, yes, but the fact that a V-6 engine can almost compete with a larger V-8 in terms of power is telling.
4. Out with the old
Modern engines are also the result of a gradual replacement of the mechanical parts with electronic ones. This is because electrical parts tend to be less prone to wear and tear like mechanical ones, for one.
They also require less frequent tune-ups, per se. Parts like pumps have increasingly become replaced with electronically controlled ones rather than their analog ancestors.
Carburetors have been replaced with throttle bodies and electronic fuel injection systems. Distributors and caps have been replaced with independent ignition coils controlled by the ECU. Also, sensors monitor everything, more or less.
You can also argue newer cars are less secure.
The final word
Although on a basic level modern and old car engines work via the same principle, modern engines have undergone a lot of gradual improvements over time. The main drive has been the race for efficiency over power. A nice set of side effects have resulted in modern engines becoming relatively more powerful and generally smaller. An ever-increasing reliance on electronic control and monitoring systems has slowly been replacing analog ones, for better or worse.
All in all, modern car engines are more efficient, smaller, relatively more powerful, smarter and less prone to inevitable mechanical failure. On the other hand, repairs and servicing are now a more highly skilled and time-consuming undertaking. If the price for improved efficiency is an increase in acceptance for complexity, only you can be the judge.