What are the advantages of a large displacement motor?
However, it is incorrect to compare American engines with European or Japanese ones. The reason for this lies in the fact that the engines have different designs and have very significant differences. To understand the peculiarities of American engine building, you need to delve a little into history.
Since the 1950s, large cars with powerful engines have been actively built in the USA, which were practically perfect for their time. At the same time, cars in America with native engines were built in huge quantities.
The automotive industry in Japan differed greatly from the American one. In the 50-70s, the automotive industry was just emerging in the country, which is essentially also true for European countries, where cars were not produced in a wide variety.
Naturally, American motorists were patriotic in everything, in the USA there was an opinion that a really good vehicle could only be made in America, and nowhere else. At the same time, it was large American cars that were considered the best. The bigger the car, the better it was. As a result, cars weighing almost 3 tons became widespread in the States, which forced automakers to equip their offspring with the most powerful engines.
In such a situation, the Americans took the simplest path – to increase the power of vehicles, they simply increased the engine size. From here, cars with engines of 7 and 8 liters appeared on the market, capable of delivering up to 400 hp. with. These engines made it possible to accelerate heavy and wide American cars to 100 kilometers per hour in just 9 seconds. But this eventually led to the fact that cars began to consume a lot of fuel – up to 40 liters of gasoline. But there was a lot of fuel, it was affordable and such an expense did not bother anyone.
In Europe, such an approach to the automotive industry, in principle, could not appear. There are two main reasons for this. Firstly, after the Second World War, almost all European countries experienced economic difficulties, Europeans had to rebuild countries, and not build extremely voracious cars. Secondly, Europeans are traditionally known for their stinginess and frugality, which is why they could not afford to keep such American monsters.
The result was the spread of production throughout Europe of small cars with small motors, which later began to be modernized without a significant increase in volume.
In the 70s, there was a well-known fuel crisis, as a result of which even Americans thought about how they could spend less gasoline on cars. In parallel with this, the green movement was gaining strength in the States, fighting for the preservation of the environment, who did not like the legends of the American auto industry – voracious and unenvironmental. All this eventually led to a decrease in engine power, but maintaining their volume. For example, the Buick Rivera in 1974 retained an engine capacity of 7.5 liters, but its power was reduced to 245 hp. with.
The reduction in engine power eventually led to a variety of consequences, including positive ones. First of all, large motors with low power parameters were characterized by very high torque at low speeds, thanks to which the cars received very high acceleration dynamics.
In addition, due to the low-speed engines, the cars created minimal noise while driving at constant speeds. Prone to comfort and convenience in everything, the Americans took it with a bang.
As a result, American car manufacturers have maintained a tradition of building large displacement engines. Today, the world-famous Grand Cherokee has a 5.2-liter engine with a power of only 220 hp. with. However, it has important advantages – excellent torque.
Conversely, the BMW has more power and a smaller engine, but its peak torque is higher than that of the Cherokee. This feature applies to almost all cars of Japanese and European production.
In other words: the more power with a smaller engine size, the faster the motor rotates.
That is, so that any Japanese-made car with 200 hp. and with two liters of engine it could accelerate just like the American Cherokee, its engine should run at 8000 rpm. At the same time, the Cherokee achieves excellent acceleration at just 3000 rpm.
Summing up, we can note the most important:
- The speed of acceleration of the vehicle is directly affected not by its maximum power, but by the torque. The lower the peak torque is in terms of engine speed, the faster the car will accelerate. This is the main advantage of American cars with large engines.
- Engine power primarily determines the maximum speed, and not the dynamics of the acceleration.
- American engines are characterized by low power, but they have a lot of torque at low speeds, which has a very positive effect on their durability.
Simply put, the engine in cars from the USA spins slowly, but allows the car to accelerate as quickly as possible. This is the main difference between US cars from European and Japanese ones.