The price of a car, whether new or used, varies significantly depending on the purchase date. However, in 2026, the classic calendar (end of quarters, open days) is no longer sufficient to explain price discrepancies. The chosen engine type, the evolution of pricing indices, and the penalty scale weigh as much, if not more, than seasonality.
Used price index and new penalty: the data that changes the calculation
Two indicators allow for a concrete measurement of the impact of timing on the cost of a vehicle in France.
| Indicator | Value 2026 | Source |
|---|---|---|
| AUTO1 Group Index (professional used) | Lowest level since 2021, down 6.2% since the peak in April | Journal Auto, October 2026 |
| Monthly decline of the index (September) | -2.3% in one month | Journal Auto, October 2026 |
| CO₂ penalty threshold (new) | From 108 g/km | Sud Radio, November 2026 |
| CO₂ penalty ceiling (new) | Up to 80,000 euros beyond 191 g/km | Sud Radio, November 2026 |
| Weight penalty threshold (new) | From 1,500 kg | Sud Radio, November 2026 |
The used car market is entering a correction phase driven by professionals. The price index, which has fallen to its floor since 2021, indicates that the current period offers more favorable purchasing conditions than the first half of the year, regardless of the chosen month.
For a new car purchase, the 2026 penalty transforms the registration date into a major budget variable. A vehicle delivered in December 2026 rather than January 2027 may be subject to a different scale if the thresholds change at the turn of the year. It is useful to consult the Au Top website to cross-reference these fiscal parameters with the seasonal calendar.
Used electric vehicle: a market counter to the classic calendar
The demand for used electric cars reached a record level in September 2026, according to Caradisiac and Le Figaro. This segment does not follow the usual logic of end-of-quarter periods favorable to buyers.
The explanation is structural. The supply of electric vehicles in the used market remains limited compared to the growing demand. Waiting until September or the end of a quarter can lead to fewer choices and higher prices in this specific segment.
In contrast, used thermal and hybrid vehicles follow the opposite trend: the AUTO1 Group index shows a continuous decline since April. For a diesel or gasoline model, the price correction offers a wider purchasing window, less dependent on a specific month.
What this changes for engine choice
- For a used electric car, the average price increases with record demand. Buying early in the year, when stock is replenished after the holidays, remains the least risky strategy.
- For a used thermal or hybrid vehicle, the market correction since April 2026 makes negotiation more favorable, regardless of the season.
- For a new vehicle subject to the penalty, the registration date matters more than the date of signing the order form. A delivery delay can change the total cost by several thousand euros.
New purchase price: why the registration date weighs more than the discount
Competitors extensively detail year-end discounts and quarterly targets for dealers. These levers exist. However, for models subject to the penalty, the cost difference related to the tax scale can far exceed the negotiated discount.
The CO₂ penalty for 2026 starts at 108 g/km and can rise up to 80,000 euros for vehicles exceeding 191 g/km. The weight penalty applies from 1,500 kg. A thermal SUV from brands like Renault or Toyota, for example, can exceed both thresholds simultaneously.
Negotiating a discount of a few hundred euros at the end of the quarter loses its appeal if the delivery slips into a less favorable fiscal year. The delivery and registration calendar significantly alters the total cost well beyond what commercial negotiation can achieve.
Vehicles in stock: the most reliable compromise
Cars already present in the dealer’s inventory have two advantages: a controlled registration date (the applicable scale is known) and often a higher negotiation margin, as the immobilized vehicle costs the professional in stock financing.
A model in stock for several weeks, even if it does not exactly match the desired configuration, can represent a net saving greater than that of a custom order delivered two months later under a potentially stricter scale.
Private vs. professional used: the price gap according to the period
The correction measured by the AUTO1 Group index concerns transactions between professionals. The prices practiced between individuals do not follow exactly the same curve.
Individuals often sell in connection with personal events (moving, change of situation) rather than based on commercial objectives. Seasonality is less pronounced, but certain periods generate an influx of listings: January (after the holidays), March (changing vehicles before spring), and September (back to school).
The abundance of listings among individuals increases the buyer’s negotiation power. For popular models like the Dacia Duster, Renault Captur, or Toyota hybrids, monitoring the volume of available offers provides a more reliable indication than the simple calendar.
- Checking the value of the targeted model across several sources before negotiating helps identify if the asking price already incorporates the market decline.
- A vehicle listed for sale for more than three weeks generally offers more room for discussion than a recent listing.
- In the electric segment, the relative rarity of the used supply makes negotiation more difficult, even in typically favorable periods.
The ideal moment for a car purchase in 2026 depends less on the month than on three variables: the targeted engine type, the applicable tax scale at the registration date, and the dynamics of the supply in the relevant segment. In the thermal used market, the price correction since April creates a favorable window. In the used electric market, record demand drives prices up. In the new market, the penalty may weigh more than any seasonal discount.
