Fiscal horsepower and car insurance in Belgium: what each CV really costs

Fiscal horsepower does not set your premium. It sets your road tax, and the bill there is steeper than most drivers assume: €300.96 a year for an 8 CV Golf in Wallonia and Brussels, €539.09 for the same car as a 2.0 TDI, even though both deliver identical power. Here is where every euro goes, box by box on the registration certificate.

€300.96 a year for 8 fiscal horsepower, or 85% of the liability premium

Belgium's annual road tax scale is public, identical in Wallonia and the Brussels Region, and built on a single input: engine displacement, converted into fiscal horsepower (chevaux fiscaux in French, fiscale pk in Dutch).

Two breaks jump out. A fiscal horsepower costs around €57 a year up to 10 CV, then €123.69 from the step to 11 CV, and €320.10 once past 3,050 cm³. The scale is not linear: it hardens at two precise points, the first of which falls exactly on the 1,950 cm³ boundary, which is to say exactly where the two-litre engines that equip a large share of the Belgian family fleet sit.

Now set that amount against a premium. On this site's reference profile, compulsory third-party liability cover costs €353 a year. An 8 CV car pays €300.96 in road tax, or 85.3% of its liability premium. At 11 CV the tax rises to €539.09 and exceeds the liability premium by €186.09.

For an 11 CV car, the state costs one and a half times what compulsory insurance costs.

Does fiscal power influence the price of car insurance?

Barely, and never directly.

Belgian insurers price on real engine power in kilowatts, the vehicle's catalogue value, the cost and availability of parts, the postcode, driver age and licence seniority, declared annual mileage and bonus-malus level. Displacement appears in none of those grids as a criterion in its own right. The threshold Belgian practitioners quote sits around 75 kW: above it the contribution rises, because powerful vehicles are over-represented in claims and their repairs cost more.

Yuzzu puts it bluntly in its own public briefing: fiscal power is not directly used to calculate the premium, even though it gives an indication of engine power. The nuance is the one separating a correlation from a tariff. Large displacement often travels with plenty of kilowatts, and it is that second variable which ends up in the price.

The Bureau de Tarification, Belgium's statutory last-resort mechanism for drivers who can no longer find liability cover on the market, likewise sets its premium according to vehicle power, driver age and claims history. Not displacement.

Two 150 hp Golfs, €238.13 apart in tax

The demonstration fits inside a single model, in four versions commonly registered in Belgium.

Read the last two rows. Same brand, same body, same 110 kW, same licence category, same use: €238.13 apart in tax every year, that is €2,381.30 over ten years of ownership, for a 470 cm³ difference nothing makes visible from the driver's seat.

Now read rows two and three. Moving from the 116 hp 1.5 TSI to the 150 hp version adds 25 kW, a 29.4% power increase, and costs exactly zero euros in extra tax. The tax office sees nothing, the insurer sees everything. The two scales measure different things, which is why no "insurance price by fiscal horsepower" grid exists in Belgium: it would lump together risks that actuaries keep apart.

The first row, finally, gives the one trade-off that cuts both ways. Between the 1.0 TSI and the 116 hp 1.5 TSI, 4 kW separate the two engines, a 4.9% power gap, for €114.71 in extra annual tax, a 61.6% rise. The small three-cylinder is therefore penalised by the insurance market in negligible fashion and rewarded by the tax office in massive fashion.

Where each criterion actually bites, line by line

One table sums up the Belgian mechanics and heads off three quarters of the misunderstandings.

Exactly one cell puts fiscal horsepower to work over the long run: the annual road tax. Everywhere else it has retreated or never counted.

Wallonia has formalised that. Its registration tax reform, in force since July 2025, removed fiscal power from the calculation and replaced it with a formula combining a base amount that degrades with vehicle age, a CO₂ coefficient, a maximum authorised mass coefficient and an energy coefficient. The mass pivot is set at 1,838 kg. A Volkswagen Golf 8 petrol rated 85 kW, weighing 1,890 kg and emitting 122 g/km of CO₂ thus pays €113.46 in registration tax, according to the worked examples run on the SPW Finances simulator on 17 February 2026.

Flanders keeps fiscal horsepower as its basis, but corrects it. The annual tax is obtained by applying to the base amount per fiscal horsepower a CO₂ correction, raised by 0.30% per gram above 149 g/km, then an air quality correction tied to the Euro standard. The base scale runs from €82 at 4 CV to €2,247 at 20 CV for the period from 1 July 2026 to 30 June 2027. Our reference profile, living in Flemish Brabant, therefore falls under that regime, and its exact amount is read on the Flemish Tax Portal simulator, not on the Walloon scale.

Which car is cheapest to insure and to tax?

The one that wins on both scales at once, and they do not overlap.

For the premium, the commanding variable is power in kilowatts, followed by catalogue value as soon as you take omnium cover. On the reference profile, the full omnium supplement comes to €782 a year for a catalogue value of €31,670, that is €24.69 a year per €1,000 of catalogue value. A richer trim adding €3,000 of catalogue price therefore costs roughly €74 a year in omnium, every year, for as long as the cover runs. Material damage cover on its own accounts for €14.97 per €1,000.

For the tax, the commanding variable is displacement, and the profitable move is to stay on the right side of a band boundary. Choosing 1,950 cm³ rather than 1,951 is worth €123.69 a year. Choosing 1,550 rather than 1,551 is worth €57.55. The insurer-by-insurer detail, once the engine is settled, sits in our ranking of the best car insurers.

Here are the boxes to read before signing an order form, in the order in which they produce euros.

• Box P.2, power in kW. The figure that drives the premium, the Walloon registration tax and part of the acceptance rules. Above 75 kW, expect a loading; above 150 kW, check the registration tax before buying.
• Box P.1, displacement. The figure that drives the annual tax. Work out which band of the scale it falls into, not its raw value.
• Catalogue value including VAT. The figure that drives the omnium supplement, at roughly €24.69 a year per €1,000 on our profile.
• Box F.1, maximum authorised mass. Decisive for the Walloon registration tax since 2025, with a 1,838 kg pivot that also catches heavy electric cars.
• Box V.7, WLTP CO₂ emissions. Decisive for the Flemish correction and for the Walloon registration tax.
• Parts and approved repairer costs. Invisible on the registration certificate, very visible on an omnium quote.

Working out your fiscal horsepower without missing one

The formula everyone publishes divides displacement by 200. A 1,600 cm³ engine gives 8 CV, a 2,000 cm³ engine gives 10. It is convenient, it is repeated by Touring CarSelect as much as by the direct writers, and it is regularly out by one horsepower.

Take our Golf again. Its 1.5 TSI displaces 1,498 cm³, which gives 7.49 by division, so 7 CV if you round down. The official scale places the whole 1,351 to 1,550 cm³ band at 8 CV. The gap between the two readings is worth €57.55 a year, every year, or €575.50 over ten years for a rounding error. The point holds at the other end: a 999 cm³ engine gives 4.995 by division, while the 951 to 1,150 cm³ band classes it at 6 CV.

Keep the hierarchy of sources in mind. The registration certificate beats the scale, the scale beats the formula, and the formula only serves to estimate an order of magnitude before the paperwork is in front of you.

Fiscal horsepower limits for young drivers

No legal limit exists in Belgian law. The constraint is commercial, and it bears on kilowatts.

Companies apply internal acceptance rules that may decline a vehicle, require a loading or impose a higher deductible above a certain power threshold for a recently licensed driver. Anyone refused all liability cover may turn to the Bureau de Tarification. The amounts at stake, how long the loading lasts and the levers for reducing it are quantified in our article on young driver car insurance.

Method, reference profile and sources

Every premium figure quoted applies to this site's reference profile: a 35-year-old driver, Volkswagen Golf 1.5 TSI, living in Flemish Brabant, no claims for five years, around 15,000 km a year.

The premiums of €353 for liability and €1,135 for full omnium, along with the omnium supplement of €782 and the material damage cover at €474, are in-house averages calculated across the nine insurers present in the three public rate grids published by Mon-Assurance-Auto (Yago S.A., broker registered with the FSMA under number 114863), recorded on 26 January 2026. The profile behind those grids differs from ours in age, province and mileage: only the gaps and ratios are claimed as transposable, never the absolute amounts as a personal quote. The catalogue value of €31,670 including VAT was recorded on 31 August 2026 from the Moniteur Automobile price list.

The annual road tax scale for Wallonia and the Brussels Region comes from the car tax file published by Mon-Assurance-Auto, which cites as official sources the SPW Finances brochure and MyTax.brussels; it is valid until 30 June 2026 and was consulted on 18 September 2026. The principle of indexation every 1 July was verified against FLEET.be, published 10 July 2025. The Walloon registration tax formula and the €113.46 example for an 85 kW petrol Golf 8 come from worked examples run on the SPW Finances simulator on 17 February 2026. The Flemish mechanism, its base scale of €82 to €2,247 and the 0.30% per gram CO₂ correction above 149 g/km apply to the period from 1 July 2026 to 30 June 2027; the exact amount is calculated on the region's official simulator.

The technical specifications of the four engines, displacement and power, come from public manufacturer data sheets. The fiscal horsepower figures shown are those that follow from the bands of the scale; the number that binds you remains the one on your own registration certificate. The 75 kW threshold above which the contribution rises is a market rule reported by several Belgian insurance information portals, not a published tariff from any named insurer.

This site compares and calculates. It does not sell insurance, is not an intermediary within the meaning of Belgian law and issues no individual recommendation: to take out cover, speak to the insurer or to a broker registered with the FSMA, the Belgian financial services regulator. The general rules of the insurance contract come from the Belgian Insurance Act of 4 April 2014, disputes with a Belgian company go free of charge to the Insurance Ombudsman, and Wikifin, the FSMA's financial education portal, publishes neutral guidance on car insurance. No insurer pays for its presence in this article and no link on this page is affiliated.

In short

Exactly one line of your Belgian motoring budget really depends on fiscal horsepower, and it is not the insurance. It is the road tax: €186.25 at 6 CV, €300.96 at 8 CV, €539.09 at 11 CV in Wallonia and Brussels, with a €123.69 jump once past 1,950 cm³. The premium, by contrast, turns on the kilowatts in box P.2, the catalogue value and your postcode, and two cars of identical displacement can be priced very differently. Before settling on an engine, cost the two scales separately: the premium simulation for the insurance, the scale above for the tax. Then line the offers up on the comparison tool and check the insurer-by-insurer detail in our ranking of the best car insurers. Our pieces on insurance premium tax, on the costed causes of a premium increase and on the price of comprehensive cover complete the calculation.