What is the power of an engine?

SummaryWhat does power mean and how is it measured for an engine? What legal and financial differences make a more powerful engine?

What does power mean and how is it measured for an engine?

D 'Where does the unit of measurement for power come from?

To understand how power works, you must first understand how it is measured.

The maximum power of an engine, expressed in Europe in horsepower or hp was simply a term adopted in the 18th century to compare the pulling force of a horse and a steam engine. The exercise was carried out by tying the horse or machine to a rope, itself connected to a weight of 75kg. The goal was to pull the weight as quickly as possible over a meter high. The horse was eventually found to have a maximum displacement power of 735.5 watts, so one horsepower was worth 735.5 watts.

How is it used today?

The term has today evolved to measure mechanical energy and includes every type of engine: gasoline or diesel, hybrid or hydrogen, and electric. To say that a car has 100hp means that it has as much motive power as 100hp, so 7355 watts. Generally, the more powerful a car, the higher its top speed and faster acceleration. A car with a similar but less powerful engine will accelerate slower and will have a harder time reaching the same speed.

Each region of the world has a different way of measuring engine power, the principle of operation is generally similar, however, in Europe, a method has been adopted to simplify this measurement. Here, it is the German method which was retained, called DIN, in reference to the Bavarian institute which developed it.

This method consists quite simply in measuring the power of a automotive engine directly at the clutch. It is proportional to the size of the engine block and the rotational speed of the pistons (generally expressed in revolutions per minute). The maximum power will of course be affected by the different frictions at the level of the various mechanical parts: gearbox, differential and undercarriages. Indeed, each imperfection present in the transmission results in a minimal loss of power, however, if we add all these losses, the power delivered to the wheels is no longer the same as that delivered by the engine. Thus, the standard is the same everywhere in Europe and no car is at a disadvantage.

To get an idea of ​​what a powerful car means in France, we can look at the average power of cars. produced in 2017, namely, 117hp.

Please note, in the United States, power is measured in kw or kilowatts, another measurement that can be converted as follows: a kilowatt is equal to 1000 W or 1.36 hp. The engine torque, expressed in newton meters or Nm, and proportional to the power, is also widely used by Americans but is less representative of the real power of your engine.

Les Chevaux Fiscaux, a real tax calculation unit:

Although many European inhabitants speak of DIN horsepower, the European and French legal system uses the fiscal horse or CV in all its files and administrative procedures. This new power unit is calculated from the engine power in watts but also from the C02 emissions in grams per kilometer. It allows you to realize how much your vehicle pollutes.

What legal and financial differences lead to a more powerful engine?

The differences in purchasing:

Buying a powerful car presents some differences compared to the purchase of a conventional car.

Indeed, there is in France what is called the ecological bonus-malus which implies that the more your vehicle emits effects gas greenhouse, the more your vehicle will be taxed, which can go up to € 10,500 in penalties to be paid in addition when buying a new vehicle! Although the relationship between C02 emissions and power is indirect, it is nonetheless heavily taxed. And conversely, the “cleaner” your vehicle, the greater the bonus the state will pay you, which can go up to € 6,000 in bonuses for certain electric cars.

If you buy occasion, the ecological bonus-malus does not concern you, but there will however be the C02 tax (if your car has been in service since June 1, 2004) which can go up to € 1,000. Finally, you will have to pay an annual tax each year which, depending on your registration year and your fiscal power, can also go up to 1000 €.

Note that all electric cars do not pay any taxes linked to anti-pollution laws since they are not polluting.

If ever the purchase of a powerful car interests you despite the important taxes of the French government, then you can opt for overfeeding! Choose a turbocharged engine that has lower CO2 emissions than a non-turbo engine of equivalent power (also called atmospheric). However, if it is still too expensive you can buy a car with a hybrid engine which will lower the cost of your emissions taxes even more than a turbo engine and could even give you an ecological bonus!

What differences for your budget auto?

Owning a high power car is unfortunately not without consequences, in fact, for a car, the more powerful an engine and the higher the speed, the more fuel it will be supplied. This will increase your fuel consumption, so your consumption of liters of gasoline per 100km will generally increase with engine power. To have a better performance, it is better to turn to low-displacement cars.

You will therefore see your vehicle's fuel budget increase but you will also encounter other costs such as insurance by example. Indeed, the more powerful a car, the more your insurance company will charge you because your car is more likely to have an accident than a low-powered car, and also more likely to be stolen. Be careful, however, insurance companies do not take into account the horsepower of your car but rather tax horsepower. Also, if you are a young driver and it turns out that the first car you are going to insure is relatively powerful, the insurance prices will be exorbitant compared to a common vehicle.

Finally, as powerful cars are generally produced in smaller series than conventional cars, you may have a higher maintenance cost because parts are harder to find and therefore more expensive. This also applies to your tires, because a more powerful car needs better tires to maintain normal grip. In addition, the expertise required to take care of your vehicle is not the same, so you will have to pay more labor for maintenance and spare parts are generally more expensive.

In this topic, find your used car at the best price.

Buy your used car with confidence with CapCar! Whether the car you are looking for is powerful or not, CapCar can help you to find one without you having to doubt the honesty of the seller or the condition of the car. Indeed, all our cars are checked with a fine comb before being put on line on our site. With CapCar you know exactly what you buy, then go ahead and trust CapCar!

If you are planning to buy a new car, here is a table showing the recommended power to have depending on the vehicle category .