The fiscal power of a vehicle, expressed in fiscal horsepower (CV), is an administrative value recorded in section P.6 of the registration document. It does not directly reflect the mechanical power of the engine but serves as a basis for calculating several taxes and auto insurance rates. A vehicle with 9 fiscal horsepower falls into a mid-high range, often associated with sedans, compact SUVs, or station wagons equipped with engines between approximately 150 and 200 DIN horsepower.
Calculating fiscal power: what the P.6 box really indicates
The fiscal power results from a regulatory formula that combines the maximum net power of the engine (in kilowatts) and CO2 emissions. Therefore, it is not simply a reflection of engine displacement or torque.
Two vehicles displaying the same mechanical power can have different fiscal powers if one emits more CO2. A gasoline SUV with 150 DIN horsepower may have a fiscal power of 9 CV, while a hybrid sedan with comparable power may drop to 6 or 7 CV due to its reduced emissions.
This mechanism explains why engine type and fuel type weigh as much as gross power in the final result. Before comparing two models, checking the P.6 value on the registration document remains the only reliable reference, as online simulators do not always account for the latest regulatory changes.
To better understand the advantages and disadvantages of 9 fiscal horsepower, it is essential to first understand how this value impacts the actual costs of ownership.
Cost of the registration document for a vehicle with 9 fiscal horsepower
The price of the registration document directly depends on the fiscal power, multiplied by the unit price of the fiscal horsepower set by each region. This rate varies significantly from one region to another.
Moving from 7 to 9 fiscal horsepower mechanically increases the price of the registration document by two units of regional tax. In some regions where the unit price exceeds the national average, the difference can represent several tens of euros more.
In addition to this regional tax, there are management fees, delivery charges, and, if applicable, the ecological penalty. A vehicle with 9 CV is not automatically subject to the penalty, as it depends on CO2 emissions and not on fiscal power. A 9 CV plug-in hybrid may avoid the penalty, while a gasoline model with the same fiscal power will be subject to it.
Impact of 9 fiscal horsepower on auto insurance premiums
Insurers use fiscal power as one of the pricing criteria. The higher the fiscal power, the greater the statistical risk of a serious accident or theft is deemed, which translates into a higher premium.
A vehicle with 9 fiscal horsepower falls into a range where the insurance premium increases noticeably compared to a model with 5 or 6 CV. The difference depends on the driver’s profile, geographical area, and level of coverage chosen, but fiscal power remains a structuring factor in the quote.
Three elements amplify or moderate this impact:
- The driver’s profile: a young driver in a 9 CV will incur a more significant surcharge than an experienced driver with a good no-claims bonus
- The type of coverage: in comprehensive insurance, the premium difference between a 6 CV and a 9 CV is more pronounced than in third-party coverage
- The market value of the vehicle: a recent and expensive-to-repair model will increase the bill, regardless of fiscal power alone
Kilometric scale and tax deduction with 9 CV
Employees who opt for actual expenses instead of the flat-rate deduction can deduct their commuting trips using the kilometric scale published annually by the tax administration. This scale is indexed to the fiscal power of the vehicle.
A vehicle with 9 CV entitles the owner to a higher kilometric allowance than a model with 5 or 6 CV, which can partially offset the additional insurance and registration document costs for high-mileage drivers. The scale caps the power taken into account at 7 CV for cars, meaning that beyond this threshold, the deductible amount per kilometer does not increase.
This capping at 7 CV is a point often overlooked. In practice, a vehicle with 9 CV does not provide any additional tax advantage compared to a 7 CV in the context of the kilometric scale. Therefore, the interest of this fiscal power in terms of deduction is null if the purchase motivation is based on tax optimization.
Automobile taxation in 2028: a risk of increased costs for 9 CV
The 2026 finance bill proposes a tightening of taxation on powerful passenger vehicles starting in 2028. Taxation would become particularly heavy beyond 10-11 CV, but it would begin at 3 CV with increased progressivity.
A vehicle with 9 CV would then be close to the high penalty zone. For a purchase in 2025 or 2026, this means that the resale value of the vehicle could be affected in the medium term if future buyers anticipate higher ownership costs.
Moreover, for vehicles whose first registration occurs after July 1, 2026, the formula for calculating fiscal power could be modified, potentially changing the P.6 value displayed for identical engines. A model classified as 8 CV before this date could switch to 9 CV, or vice versa.
Choosing 9 fiscal horsepower: for which driver profile
The question is not limited to a number on the registration document. The choice depends on the actual use of the vehicle and the personal tax context.
- A driver covering less than 15,000 km per year, residing in an urban area, has no financial interest in increasing fiscal power: the additional insurance and registration document costs will not be compensated
- A driver who regularly tows, uses busy highways, or needs strong acceleration will find a 9 CV to be a compromise between driving comfort and still manageable costs
- A professional in a company vehicle must consider depreciation caps and the company vehicle tax, which increase with fiscal power and CO2 emissions
The threshold of 9 fiscal horsepower remains below the most severe penalty zones of the current penalty system, but the regulatory trajectory towards 2028 reduces this margin of comfort. Buying a 9 CV today without considering this evolution is to ignore a parameter that will weigh on the total cost of ownership in the coming years.