Older cars in the UK were assigned lower relative annual mileage indices than a new fleet in both 2005 and 2019. The figures below show how those indices varied by fuel type, vehicle age and measurement year, using a new-fleet benchmark of 1.00.
Contents
- How to read the mileage index
- Petrol cars aged 12 to 14
- Petrol cars aged 15 to 20
- Petrol cars aged 21 to 24
- Diesel cars aged 12 to 18
- Diesel cars aged 19 to 24
- Petrol and diesel patterns by age
How to read the mileage index
The figures are relative annual mileage indices for UK cars, rather than miles driven per year. A value of 1.00 represents the new-fleet benchmark used in the source. A value below 1.00 therefore indicates a lower relative annual mileage than that benchmark; it does not state a vehicle’s odometer reading or an individual owner’s annual use.
The comparison uses 2005 and 2019 measurement periods. The source labels the figures as part of the Development of the Road Transport Fleet Turnover Model. They are model-related indices for UK petrol and diesel cars, so they should not be read as a direct survey of classic British cars or as a forecast for any particular model.
| Vehicle group | Age range shown | 2005 to 2019 comparison | Benchmark |
|---|---|---|---|
| Petrol | 12–24 years | Every listed age has a higher 2019 index | 1.00 |
| Diesel | 12–24 years | Every listed age has a higher 2019 index | 1.00 |
Source for all figures: Development of the Road Transport Fleet Turnover Model.
Petrol cars aged 12 to 14
The petrol-car indices decline as age rises within both measurement periods. In 2005, the index was 0.70 at age 12, 0.66 at age 13 and 0.61 at age 14. In 2019, the corresponding figures were 0.78, 0.74 and 0.70.
| Petrol-car age | 2005 | 2019 | New-fleet benchmark |
|---|---|---|---|
| 12 years | 0.70 | 0.78 | 1.00 |
| 13 years | 0.66 | 0.74 | 1.00 |
| 14 years | 0.61 | 0.70 | 1.00 |
At age 12, the 2019 index was 0.78, compared with 0.70 in 2005. At age 13, it was 0.74 in 2019 versus 0.66 in 2005. At age 14, it was 0.70 in 2019 versus 0.61 in 2005. Each of these figures comes from the Development of the Road Transport Fleet Turnover Model, with the new-fleet benchmark at 1.00.
Petrol cars aged 15 to 20
The same age-related decline continues through the 15-to-20-year range. For petrol cars aged 15, 16 and 17 years, the 2005 indices were 0.56, 0.51 and 0.45. In 2019, they were 0.65, 0.61 and 0.57.
For ages 18, 19 and 20, the 2005 values were 0.40, 0.36 and 0.32. The 2019 values were 0.52, 0.46 and 0.42. Thus, the oldest age in this section had an index of 0.32 in 2005 and 0.42 in 2019, while the youngest had 0.56 and 0.65 respectively.
| Petrol-car age | 2005 | 2019 |
|---|---|---|
| 15 years | 0.56 | 0.65 |
| 16 years | 0.51 | 0.61 |
| 17 years | 0.45 | 0.57 |
| 18 years | 0.40 | 0.52 |
| 19 years | 0.36 | 0.46 |
| 20 years | 0.32 | 0.42 |
These are relative indices, not annual-mileage totals. The source is the Development of the Road Transport Fleet Turnover Model, and the periods are 2005 and 2019.
Petrol cars aged 21 to 24
For petrol cars aged 21 to 24 years, the indices were lower again. In 2005, the sequence was 0.28 at age 21, 0.24 at age 22, 0.21 at age 23 and 0.18 at age 24. In 2019, the sequence was 0.35, 0.30, 0.30 and 0.22.
| Petrol-car age | 2005 | 2019 |
|---|---|---|
| 21 years | 0.28 | 0.35 |
| 22 years | 0.24 | 0.30 |
| 23 years | 0.21 | 0.30 |
| 24 years | 0.18 | 0.22 |
The age-24 value is the lowest petrol index listed for either period: 0.18 in 2005 and 0.22 in 2019. The age-21 value is 0.28 in 2005 and 0.35 in 2019. The figures are reported in the Development of the Road Transport Fleet Turnover Model, against a new-fleet benchmark of 1.00.
Diesel cars aged 12 to 18
Diesel cars also show a descending index with increasing age. In 2005, the indices for ages 12 through 18 were 0.52, 0.48, 0.46, 0.43, 0.40, 0.37 and 0.34. In 2019, they were 0.60, 0.58, 0.55, 0.52, 0.48, 0.47 and 0.42.
| Diesel-car age | 2005 | 2019 |
|---|---|---|
| 12 years | 0.52 | 0.60 |
| 13 years | 0.48 | 0.58 |
| 14 years | 0.46 | 0.55 |
| 15 years | 0.43 | 0.52 |
| 16 years | 0.40 | 0.48 |
| 17 years | 0.37 | 0.47 |
| 18 years | 0.34 | 0.42 |
The 2019 index at age 12 was 0.60, while the age-18 index was 0.42. In 2005, the same endpoints were 0.52 and 0.34. These UK diesel-car indices are from the Development of the Road Transport Fleet Turnover Model.
Diesel cars aged 19 to 24
Among diesel cars aged 19 to 24 years, the 2005 indices were 0.31, 0.28, 0.25, 0.22, 0.19 and 0.16. Those values correspond to ages 19, 20, 21, 22, 23 and 24. In 2019, the same age sequence was 0.38, 0.35, 0.32, 0.29, 0.26 and 0.23.
| Diesel-car age | 2005 | 2019 |
|---|---|---|
| 19 years | 0.31 | 0.38 |
| 20 years | 0.28 | 0.35 |
| 21 years | 0.25 | 0.32 |
| 22 years | 0.22 | 0.29 |
| 23 years | 0.19 | 0.26 |
| 24 years | 0.16 | 0.23 |
The lowest diesel index in the supplied age range is 0.16 for a 24-year-old car in 2005. For the same age in 2019, the index is 0.23. At age 19, the values are 0.31 in 2005 and 0.38 in 2019. The source is the Development of the Road Transport Fleet Turnover Model, with 1.00 as the new-fleet benchmark.
Petrol and diesel patterns by age
Across the listed ages, every 2019 index is higher than its 2005 counterpart for both fuel types. The supplied figures therefore show a consistent period-to-period increase in the relative index, while still remaining below 1.00 at every age from 12 through 24 years.
At age 12, petrol is indexed at 0.70 in 2005 and 0.78 in 2019, while diesel is 0.52 and 0.60. At age 18, petrol is 0.40 and 0.52, while diesel is 0.34 and 0.42. At age 24, petrol is 0.18 and 0.22, while diesel is 0.16 and 0.23. These comparisons use the same UK geography, age definition and new-fleet benchmark described by the source.
| Age | Petrol 2005 | Diesel 2005 | Petrol 2019 | Diesel 2019 |
|---|---|---|---|---|
| 12 years | 0.70 | 0.52 | 0.78 | 0.60 |
| 18 years | 0.40 | 0.34 | 0.52 | 0.42 |
| 24 years | 0.18 | 0.16 | 0.22 | 0.23 |
The Development of the Road Transport Fleet Turnover Model is the source for each index in this comparison. For classic-car readers, the practical boundary is important: these numbers describe relative annual mileage by age and fuel type, not a guaranteed mileage level for an individual historic vehicle, a specific British marque or a particular year of manufacture.
The age bands also provide a consistent way to place the figures in context. The 12-year observations are higher than the 24-year observations for petrol and diesel in both periods. Petrol moves from 0.70 to 0.18 across those endpoints in 2005, and from 0.78 to 0.22 in 2019. Diesel moves from 0.52 to 0.16 in 2005, and from 0.60 to 0.23 in 2019. The intermediate ages fill out the same broad progression rather than supplying a single threshold for when a vehicle becomes historic.
Because the source gives indices rather than miles, the figures are most useful for comparing relative patterns. They can show the position of an age group against the 1.00 new-fleet reference and distinguish the 2005 series from the 2019 series. They cannot, on their own, convert a classic British car’s age into a predicted annual mileage or describe how far a particular owner drives.