Porsche 911 vs Aston Martin Vantage: €4,998.69 apart on Walloon road tax alone

On the spec sheet, the Porsche 911 and the Aston Martin Vantage are separated by a stopwatch and a soundtrack. On a Walloon tax assessment, they are separated by a millimetre of displacement. The 911 Carrera displaces 2,981 cc. The Vantage displaces 3,982 cc. The tax-band boundary runs between them, and that boundary is worth €4,998.69 over three years of ownership.

Three Belgian terms recur below and are worth defining once. VRT (taxe de mise en circulation, TMC) is the one-off registration tax due when a vehicle first enters service, set regionally. Road tax (taxe de circulation) is the annual circulation tax, still calculated on engine displacement in Wallonia. The historic plate (plaque ancêtre, O plate) is the Belgian status granted to vehicles over 30 years old, with a flat road tax in exchange for restricted use.

Porsche 911 or Aston Martin Vantage: which is cheaper to keep?

The Porsche, and the gap comes from neither fuel nor tyres. It comes from two lines in a tax scale that nobody reads before signing.

The 911 Carrera (992.2) runs a 2,981 cc twin-turbo flat-six producing 290 kW. The Vantage runs a 3,982 cc twin-turbo V8 producing 489 kW. In the Walloon road-tax scale, still calculated on displacement, the first falls into the 2,751 to 3,050 cc band, i.e. 15 fiscal horsepower. The second falls into the 3,951 to 4,150 cc band, i.e. 20 fiscal horsepower, the last rung of the table before the per-horsepower formula takes over.

Five thousand euros, on two cars that have not yet seen a workshop.

How much is the road tax on each in Belgium?

€1,075.54 a year for the 911 Carrera, €2,741.77 for the Vantage, in Wallonia, additional decimes included. The SPW Finances scale is valid from 1 July 2026 to 30 June 2027 and is indexed every 1 July.

The Walloon table climbs in steps and the steps hurt. Going from 15 to 16 fiscal horsepower, that is 71 cc more, adds €333.16 a year. Going from 15 to 20 fiscal horsepower multiplies the bill by 2.55.

Why do both pay the same registration tax?

Because the Walloon formula saturates before it can separate them.

Since 1 July 2025, Walloon VRT is no longer calculated on fiscal horsepower. It multiplies a base amount tied to power in kilowatts by the ratio of CO₂ to 136 under WLTP, by the ratio of maximum authorised mass to 1,838, then by an energy coefficient that equals 1 for petrol. Above 155 kW, the base amount on a new car is €5,159.25. And the text sets a hard limit: the amount payable can never exceed €9,000.

Put the numbers in. The 911 Carrera emits 226 to 237 g of CO₂ per kilometre under WLTP depending on version, for a maximum authorised mass recorded at 1,860 kg. On the cleanest version, the formula returns roughly €8,676. On the highest-emitting one, it passes €9,000 and gets trimmed back to the ceiling. The Vantage, quoted at 274 g of CO₂ under WLTP, clears €10,300 before the mass factor even applies: ceiling, no argument.

The saturation threshold can be calculated: beyond roughly 436,000 in CO₂ multiplied by maximum authorised mass, a petrol car above 155 kW pays €9,000 and not a euro more.

The practical consequence is counter-intuitive. On a sports car of this calibre, adding displacement costs nothing extra at registration, because the ceiling is already reached. It costs every year, for life, on road tax. The annual line is the one to watch, not the entry line.

For how long will each brand keep warranting the car?

Fifteen years at Porsche, ten at Aston Martin. New-car cover favours Aston Martin, total duration hands it back to Porsche.

A new Porsche leaves with two years of worldwide warranty and no mileage limit. A new Aston Martin leaves with three years, unlimited mileage too. A one-year head start for the British car, on paper.

The handover changes everything. Porsche Approved is taken out in 12, 24 or 36-month blocks, with no mileage limit during the covered period, at any point before the vehicle's 14th anniversary and as long as the odometer has not passed 200,000 km, with cover that can extend to the fifteenth year. Aston Martin's Timeless programme requires a car under ten years old with an up-to-date service history, and adds twelve months of cover on top of whatever factory warranty remains.

What annual servicing budget should you plan on a 911 and on a Vantage?

I will not publish a Belgian figure, because no verifiable one exists.

Neither Porsche nor Aston Martin publishes a workshop rate for Belgium, and their importers do not either. The only figures available from a named source are American: around 1,500 to 2,000 dollars a year of authorised-workshop servicing on a Vantage, 700 to 900 dollars per axle for a set of brakes, and a clutch replacement quoted at 5,000 to 7,000 dollars, recorded on ConsumerAffairs on 31 August 2026. Hourly rates, taxation and network density bear no relation to Belgium. I quote them as an American order of magnitude, not as a Belgian reference, and I am not converting them into euros.

One thing does check out on both sides, and it weighs more than a bracket: the density of the approved network. Porsche operates dealerships and authorised workshops across all three regions. Aston Martin has a handful in the whole country. On a car stuck waiting for a part, the gap is not read in euros per hour, it is read in weeks.

How much does it cost to insure an Aston Martin V8 Vantage?

No Belgian insurer publishes a rate table for this segment, so no figure appears here. Two mechanisms decide the number and are worth understanding before asking for a quote.

The first is agreed value. On a car whose market value does not follow a linear depreciation curve, the sum paid on a total loss has to be fixed in the policy, not estimated after the event by an assessor consulting a market guide. The second is the track-use exclusion, near-systematic in Belgian policies, third-party and comprehensive alike, with timed sessions excluded without exception. Day-rate cover exists and is paid for separately. Get your position confirmed in writing before you drive.

Which depreciates less and which sells faster?

The 911, in a proportion measured in the United States and nowhere else publicly.

Over five years, iSeeCars records 17 percent of value lost for the Porsche 911 against 38.4 percent for the Aston Martin Vantage, figures accessed on 31 August 2026 on the American market. No public, dated, verifiable series measures the same thing on the Belgian used market. The ratio between the two matches what I have seen on Belgian listings for years, but an observation is not data: I flag the gap, I do not apply it to a Belgian price.

A Belgian signal does exist, and it is blunter than a percentage. As of 31 August 2026, the Aston Martin Vantage carries the "no longer marketed" tag in Moniteur Automobile's new-car price grid, and no Belgian list price is published for it. The Porsche 911 Coupé 2026 is listed from €139,199 to €276,163, and the 911 Cabrio 2026 from €153,637 to €290,601. A range continuously priced on the local market and a range absent from the grid do not produce the same volume of used cars, nor the same liquidity on resale.

The verdict, line by line

Over three years and registered in Wallonia, the Porsche 911 Carrera starts with a €4,998.69 head start on road tax alone, with registration tax strictly identical since both hit the €9,000 ceiling. Add four extra years of officially available warranty, a markedly denser approved network, and half the depreciation on the only public series that exists.

The Aston Martin Vantage hands back one year of factory warranty and a rarity that has value for whoever is looking for it. It charges for that every year, on a tax line that will not move for as long as the car is on the road.

The list price says one thing, the tax assessment says another, and the second one comes back every twelve months.

In the same segment, Ferrari and Lamborghini separate on different lines, essentially included servicing and the track exclusion. If the purchase is second-hand, the traps of the Belgian used market are worth reading before you travel to see a car, and luxury car depreciation details which models hold their value. Models costed line by line are in the luxury car ranking.

Sources

• SPW Finances, road tax amounts, additional decimes included, valid 1 July 2026 to 30 June 2027, accessed 31 August 2026: €1,075.54 for the 2,751 to 3,050 cc band (15 hp), €1,408.70 at 16 hp, €2,408.34 at 19 hp, €2,741.77 for the 3,951 to 4,150 cc band (20 hp), €48.61 flat for historic vehicles over 30 years old.
• SPW Finances, registration tax amount for cars, dual-purpose cars and minibuses, valid 1 July 2026 to 30 June 2027, accessed 31 August 2026: formula combining base amount, CO₂ divided by 136 under WLTP, maximum authorised mass divided by 1,838 and an energy coefficient, base amount of €5,159.25 above 155 kW with a 100 percent degressivity coefficient when new, coefficient of 1 for petrol, amount capped at €9,000 and never below €50.
• Porsche Belgium, Porsche Approved warranty, accessed 31 August 2026: contracts of 12, 24 or 36 months with no mileage limit, subscription possible before the vehicle's 14th anniversary and up to 200,000 km, cover extendable to the fifteenth year, coverage level aligned with the new-vehicle warranty.
• Porsche Belgium, new-vehicle warranty, accessed 31 August 2026: two-year worldwide warranty with no mileage limit.
• Porsche Newsroom, 911 Carrera press kit, accessed 31 August 2026: combined CO₂ emissions of 226 to 237 g/km under WLTP for the 911 Carrera, 231 to 235 g/km for the 911 Carrera Cabriolet.
• Mechanical specifications of the Porsche 911 Carrera (992.2) recorded on 31 August 2026: 2,981 cc twin-turbo flat-six, 290 kW at 6,500 rpm, maximum authorised mass of 1,860 kg.
• Mechanical specifications of the Aston Martin Vantage (2025 model year) recorded on 31 August 2026: 3,982 cc twin-turbo V8, 489 kW, combined CO₂ emissions of 274 g/km under WLTP on the Vantage S.
• Moniteur Automobile, Porsche 911 prices, recorded 31 August 2026: 911 Coupé 2026 from €139,199 to €276,163, 911 Cabrio 2026 from €153,637 to €290,601, published annual taxes of €2,374.94 in Brussels and €3,051.80 in Flanders for the 2026 Coupé, marked "NC" for Wallonia.
• Moniteur Automobile, Aston Martin Vantage prices, recorded 31 August 2026: "no longer marketed" on both the coupé and the Roadster, no Belgian list price published.
• iSeeCars, Porsche 911 and Aston Martin Vantage comparison, accessed 31 August 2026, American market: 17 percent of value lost over five years for the 911, 38.4 percent for the Vantage.
• ConsumerAffairs, Aston Martin maintenance costs, accessed 31 August 2026, American market: around 1,500 to 2,000 dollars a year at an authorised workshop, 700 to 900 dollars per axle for brakes, 5,000 to 7,000 dollars for a clutch replacement.
• Aston Martin, Timeless certified pre-owned programme, recorded 31 August 2026 from the official network: three-year new-car warranty with unlimited mileage, eligibility limited to vehicles under ten years old with an up-to-date service history, twelve additional months of unlimited-mileage cover.