When choosing a car or studying its technical characteristics, many drivers come across a mysterious term that often appears in old documents or specific reference books. That's what they call it. before-tax horsepowerThis is a concept that causes confusion among untrained motorists. At first glance, it seems that we are talking about some hidden power that disappears after visiting the tax office, but in fact everything is much more prosaic and related solely to the history of taxation.
In today’s world, where the standard for measuring the power of the internal combustion engine is kilowatts (kW) real horsepowerThe term seems anachronistic. However, understanding the nature of the tax is essential for a proper calculation of the transport tax, especially if you own a car with a history or are studying archival data. It is important to note that the engine does not lose power due to taxes, only the method of calculating it for fiscal authorities changes.
In this article, we will look in detail at where the term came from, how it relates to modern standards, and why it is still mentioned in the automotive environment. You will learn how to avoid errors when registering a vehicle and understand the difference between the actual engine traction and the numbers on the receipt.
Historical context of the term
The concept of “tax” or “before tax” forces originates in the early twentieth century, when the automotive industry was just beginning, and states were looking for ways to effectively tax a new mode of transport. Then engineers and officials faced a problem: how to estimate the power of the engine, if it was difficult and expensive to measure with a dynamometer at that time? To solve this problem, a formula was developed that depended not on the actual performance of the engine, but on its geometric parameters.
Different countries have used their own methods. For example, in the UK, the RAC formula was used, which took into account only the diameter of the cylinder and their number, completely ignoring the stroke of the piston. This led to absurd situations where a huge long-piston engine could have low “tax” power, while a compact forced unit could have high power. These calculations were the basis for tax burden.
⚠️ Note: Historical calculation formulas often underestimated the real power of long-piston engines, which encouraged engineers to build such engines, even at the expense of their efficiency.
With the development of technology and the advent of accurate stands for measuring torque and power, the need for such conventional units has disappeared. However, in some countries, including Russia (in the form of an engine-tax reference), the echoes of this system persisted. The term “before tax” originated as a contrast of real power, showing that the figure in the document serves only as a basis for collecting duties, and does not reflect the dynamics of acceleration.
Difference between kWh, hp and tax units
The modern motorist should clearly distinguish between three concepts that are often mixed in everyday life. First of all, it's kilowatts The official unit of measurement in the SI system, which is indicated in the technical documentation and PTS of most modern cars. Secondly, this horsepowerThe scaling of the machine is approximately 0.7355 kW and is a familiar indicator of the dynamic capabilities of the machine.
The third concept is precisely those conventional units used for fiscal calculations. In Russia, for example, the transport tax is calculated based on horsepower, but this power is taken from the PTS, where it is already converted from kilowatts. The problem arises when old documents or foreign catalogues contain values calculated according to outdated British or American standards (HP) that differ from metric hp.
The American horsepower (hp) is slightly larger than the metric (1 hp ≈ 1.0138 hp). If during customs clearance or registration of a car to use the wrong conversion rate, you can get a discrepancy in the documents. It is in such cases that the topic of “tax” values comes up, when it is necessary to bring US or British data to the Russian tax standard.
Table of conformity of power measures
1 hp (metric) = 0.73549875 kW|1 hp (American) = 0.74569987 kW|1 hp. ≈ 1.01387 hp|1 kW ≈ 1.35962 hp
It is important to understand that for the internal combustion engine there is no concept of “power before taxes” in the physical sense. The engine generates a certain amount of energy when burning fuel, and no government agency can reduce this physical process. All talk of power loss is purely bureaucratic.
Calculation methods in different countries of the world
Approaches to determining capacity for tax purposes have varied considerably and vary by region. Understanding these differences is critical for car importers and collectors of retro equipment. In Europe, the metric system has long been dominant, with horsepower defined as the ability to lift 75 kg to a height of 1 meter in 1 second.
The United States and the United Kingdom have their own standards. The American system SAE (Society of Automotive Engineers) for a long time allowed measurements of engine power without attachments (generator, pump, silencer), which gave inflated results known as "gross horsepower". Later, they switched to the measurement of “net horsepower” – with full equipment, which brought the figures closer to reality. These “clean” data are often the subject of disputes during registration.
- 🇩🇪 Germany: Uses metric HP. (PS), which are almost equal to the Russian, the calculation is carried out according to the DIN standard.
- 🇬🇧 United Kingdom: Historically, it used the RAC formula based on cylinder diameter, which had no direct connection to actual power.
- 🇺🇸 USA: It uses mechanical horsepower (hp) which is slightly above metric and SAE J1349 standards for measurements.
- 🇯🇵 Japan: For a long time she used her own measurement system, but now she has completely switched to kW and metric hp.
Today, international harmonization of standards has reduced differences to a minimum. In the technical passports of new cars, the power is indicated in kW, and the conversion into horsepower for tax is made according to a single mathematical algorithm. However, when working with archival data or rare models, knowledge of the national features of the calculation remains relevant.
When buying a car from a Japanese auction, pay attention to the line "Shaken" in the auction list - there is a power list, which may differ from the European version of the same model.
Transport tax and engine capacity in Russia
In the Russian Federation, the concept of “before tax horsepower” has been transformed into the question of how exactly the engine volume or power in kW is converted into the total amount of tax. The Russian tax code does not use complex physical formulas of the early XX century. The basis for the calculation is the entry in the PTS (Passport of the Vehicle) or CTS (Certificate of registration of the Vehicle).
If only kilowatts are in the column "Engine Power", they are converted into horsepower by multiplying by the coefficient. 1,35962. The result is rounded to the second digit after the decimal point according to the rules of mathematics. This is the number multiplied by the tax rate of your region. No "discounts" or "before tax" deductions are provided here.
| Power (L.S.) | Bet (Moscow, rub.) | Rate (Moscow region, rub.) | Bet (S-Petersburg, rub.) |
|---|---|---|---|
| 100 | 12 | 10 | 24 |
| 100 - 125 | 25 | 34 | 24 |
| 125 - 150 | 35 | 34 | 32 |
| 150 - 175 | 45 | 49 | 32 |
| 250 | 150 | 150 | 150 |
Particular attention should be paid to electric vehicles. In some regions, they have preferential rates or full exemption from tax for a certain period. However, the power of the electric motor is also indicated in kW and recalculated in hp. to be included in the relevant tax category if the benefit does not cover 100% of the amount.
⚠️ Note: If, after conversion, kW in hp If you get a value close to the threshold (for example, 124.9 hp), check the rounding. Rounding to 125bhp. It can move you to the next tax rate, which will significantly increase your annual payment.
The impact of chip tuning on the tax base
One of the most common questions related to power and taxes: what happens if you increase the engine power programmatically (chip tuning)? In terms of physics, the engine will start to produce more. torque and horsepower. However, from the point of view of the law, until you have made changes to the design of the car officially and have not updated the data in the PTS, for the tax inspection, your car remains the same as it was at the time of registration.
Things change if you decide to make the changes. In this case, it will be necessary to conduct a technical examination and make changes to the registration data. Only then will the “before-tax” (real) capacity become “post-tax” (official) and the amount of tax will rise. Until that moment, the state proceeds from the factory parameters specified in the documents.
☑️ Legalization of engine tuning
There is a risk, however. If the car gets into an accident and the examination shows that the real power significantly exceeds the declared in the documents, the insurance company can refuse to pay, and the traffic police can write a fine for illegal changes to the design. Therefore, it makes sense to hide the real power only until the first serious trial.
Practical tips for data verification
To avoid problems with tax calculation and registration, always check the data with the PTS when buying a car, especially a used one. Clerks errors occur when entering data, and instead of 149 hp. The database can be 151 hp, which automatically translates the car into a more expensive tax category.
If there is a discrepancy between the real power (for example, according to the results of measurements on the stand or the manufacturer's data for a specific modification) and the data in the PTS, this is a reason to contact the traffic police for adjustments. But you need to do this carefully, weighing all the pros and cons.
Always check the power in the PTS with the official manufacturer's catalog for your model and year of release - this will help to identify registration errors before charging a higher tax.
For an accurate calculation of the future tax, use online calculators on the FTS website, entering data from the certificate of registration, and not from memory or advertising booklets. Advertising "249 hp" can turn out to be "252 hp" after recalculating from kW, and it will cost you money.
FAQ: Frequently Asked Questions
Can I return the overpaid tax if the capacity in the PTS is indicated incorrectly?
Yes, if you prove that there is a technical error in the documents. To do this, you need to undergo an examination, get a new conclusion and contact the traffic police to correct the data in the register. After that, you can apply to the tax office for recalculation.
Why do different regions have different tax rates on the same capacity?
The tax code sets the basic rates, but the regional authorities are given the right to increase or reduce them up to 10 times depending on the environmental situation and the budget of the region. Therefore, the same “horsepower” in Moscow and Chechnya is different.
Is there a tax on the power of an electric car?
Yes, formally the tax is calculated based on the power of the electric motor in hp. However, in many regions (for example, Moscow, Moscow region) there are benefits that completely exempt owners of electric vehicles from paying transport tax for a certain period (usually 3-5 years from the date of registration).
How to Translate American HP into Russian HP For tax?
For accurate translation, you need to know what standard the power is measured. Roughly speaking, 1 American HP ≈ 1.014 metric hp. But officially in the PTS power should be recalculated through kilowatts: kW × 1.35962 = hp.