Today we reproduce an article by Matt Thorne at AutoPredict which documents some of the insights have gained whilst studying MoT histories and developing an AI model. Other findings unearthed from the study of MoTs can be found at AutoPredict.co.uk/blog/
In the UK every vehicle must annually have its safety, roadworthiness and emissions inspected as part of an MOT test. This happens in many countries across the world, but the UK is unique as this MOT data is available for anyone to view and have access to. The quality and quantity of data mean many exciting and previously hidden insights can be found by analysing the data. Whilst developing our AI model that predicts how long a car will last we have uncovered some of these insights. Rather than keeping these hidden, we plan to share some of these insights in the next few posts.
Today we are going to look at which car on average does the most miles before it is taken off the road. Several articles have previously been written finding the highest mileage vehicle in the world, but these only look at individual cars. These cars are often owned and maintained by an enthusiast and don’t represent every other car of the same make, model, engine type etc. We wanted to know when you look at all the cars of the same type and averaged how many miles they did before they were taken off the road, which car does the most. As you might have guessed from the title, a specific category of vehicle out does any other.
Many factors effect how long a car is kept on the road. Very few cars simply die and cannot be fixed. Averaging the final miles of a particular type of car can therefore reveal insights not just about the cars themselves, but about who tends to own them, what they are used for, and the period of time they are used in.
So which car on average does the most miles? Even just grouping cars by their manufacturer immediately reveals a clear category of cars that drives far more miles than any other… Taxis. More accurately vehicles that are specifically built to be taxis. Here we are showing the top 5 highest mileage manufacturers. London Taxis Int, Carbodies and Metrocab, are the top 3. All make cars specifically made to be taxis and on average they all do more than 250000 miles, nearly double the next nearest manufacturer Mercedes.
Grouping by manufacturer and model shows Taxis still at the top, with some models averaging more than 350000. To show some context we have added the Mercedes Sprinter to the chart. This was the first non-taxi coming in at 12th and averaging just under 200,000 miles.
Finally, grouping by manufacturer, model and engine we see London Taxi Inc TX4, 2.6 Diesel come out on top, averaging an astonishing 440000 miles. Taxis dominated the top 50, with only 7 of the top 50 cars not being taxis. 6 of these were vans, such as the Mercedes sprinter and VW Transporter and the last was the Mercedes Ambulance. Again we have added the Mercedes sprinter to the bottom of the chart. This was the highest non-taxi coming in at 26th.
To really highlight how many more miles taxis do than all other cars we have plotted the distribution of the miles reached by taxis (London Taxis Int, Carbodies and Metrocab) and all other cars. Taxis have a lot more variance in their final miles, but their average is far higher.
All this begs the question, why is it that taxis do so many more miles than other cars? On the face of it, this might seem quite simple. Taxis spend all day driving around so, of course, they will do more miles. But if a car can do so many miles, why don’t all cars? In the UK when choosing a second-hand car mileage and age are often the two major considerations when picking a reliable car. Maybe the data from taxis suggests mileage doesn’t play as big a part in how long a car stays on the road as we think. Perhaps it is just age that is the major factor?
If we look at the number of years reached by cars in the distribution below we can see that taxis do tend to last slightly longer, but on average only by less than half a year. Maybe this suggests there is a limit to how many years you can expect a car to reliably last. But also confirms that age is a big factor in how long a car will stay on the road. Perhaps most cars could do many more miles, but their age is what eventually stops them.
Clearly, age and mileage are not the only factors. Maybe there is something else that allows taxis to last so many more miles. Looking in more detail at the MOT histories themselves gives us a few more hints. For example, if a higher percentage of tests are passed it could suggest the taxis are more resilient to wear and tear or equally they may be better looked after. As you can see the percentage of tests that are passed is nearly identical between taxis and all other cars. So looking at passes on their own doesn’t reveal too much.
However, looking at each test in more detail we can start to see some differences between taxis and all other cars. Regardless of if the car passes or fails each test the mechanic may leave a list of advisories of things that would be good to be fixed, but are not critical to the car passing its MOT. By looking at the average number of advisories per test we can get a more detailed glimpse into the condition of the car. As you can see on average taxis have fewer advisories per test. They also have a higher percentage of ‘clean’ (no advisories) tests. This could indicate the taxis themselves are more resilient, or equally are better maintained. Either way, it could at least partially explain the high mileages reached.
Whilst we can’t answer for sure why taxis reach such high mileages it does show how different certain types of cars can be from the average car. We think this nicely highlights how important it is to be informed about the specific car you are looking at buying. All the data and insights we have collected about cars in the UK are available for free to everyone. Go to AutoPredict and just type in a registration number and instantly get all the related data to that specific car and also get a prediction for how long that car is likely to last.