The inaugural AM Index gives an overview of three-year/ 30,000-mile used car values across every sector. Each month AM, in conjunction with CAP, will put the spotlight on one sector, starting with superminis in the January 12 issue.

Overall
The overall graph shows a typical trend January to November, with steady depreciation offset by plate change uplifts in March and September. The movements remained fairly flat between April and August before a 5% increase in September due to plate adjustment. The used car market remained buoyant into October, leading to a rise of 0.3% rather than the more usual slight decline.

Supermini
Percentage-wise, this sector showed a 6.9% increase in March, compared with an average lift of 3.9% for the index overall. This movement was driven by a strong market performance within the sector at that time. Conversely, market performance also contributed to the below-average increase in September.

Lower medium
The lower medium sector tended to run in line with the basket as a whole between January and September. Interestingly, the average premium for diesel over petrol rose from £334 in January to £555 in November. This is due to diesel outperforming petrol in the used market in recent months.

Upper medium
Three-year/30,000 values in this sector tended to follow the pattern of the overall basket, with August being the notable exception. A 5.6% overall decrease was caused by drops in the Mondeo, Vectra and Passat ranges for 2003-registered vehicles. This was brought by weaker than expected transaction prices.

Small executive
September saw small executive prices jump by 9.3%, compared with a 5% lift for the basket as a whole. Diesel models rose by 12.8% while petrol moved by just 5.6%. These figures were driven by an increased demand for small executives and the exceptional performance of diesel.

Large executive
Large executive followed a steady trend between January and November, with gradual depreciation across all months, bar March and September. The diesel premium remained fairly constant in ‘pound note’ terms.

MPV
As with large executive, the MPV sector showed consistent movements. The uplift of 7.4% into September is higher than the overall average.

Sports
This sector acts in a slightly different manner to the rest of the market. A large increase in March is followed by a lower-than-average rise in September. This is because the vehicles within this sector (particularly roadsters) are more popular in summer, making March the most likely month to feature heavy sales.

4x4
Another segment that featured a fairly typical trend this year. A below-average increase in March was caused by drops in the BMW X5 (diesel), Land Rover Freelander (petrol) and Volvo XC90 ranges as a result of market reviews. A 3.4% drop in August was due to a lowering of values for the X5, while 2% reductions in prices for Jeep Grand Cherokee and Freelander limited the September rise to 4%.