Buying a second-hand car

● TÜV NORD and Carly advise buyers to systematically check the condition of a used car before purchasing it – from the vehicle documents to the test drive

● Digital vehicle diagnostics provide added peace of mind: relevant vehicle data can be objectively read out and assessed either at a service centre or via an app

● For electric cars, the battery condition provides key information: initial TÜV NORD assessments show a median ‘State of Health’ value of over 95 per cent

A second-hand car is often the more economical choice – but it is difficult to assess a vehicle’s actual condition from the outside. TÜV NORD and Carly advise buyers to take a structured approach before purchasing and, where possible, to use digital diagnostic technology. This allows the vehicle’s history, technical condition and – in the case of electric cars – the battery condition to be objectively verified.

Check the paperwork, history and vehicle

Complete documentation is essential: the service booklet, maintenance records and MOT reports, as well as registration certificates I and II. Checking the Vehicle Identification Number (VIN) and noting the number of previous owners provides insight into the vehicle’s history. The inspection should ideally take place in daylight and dry weather, if possible with a second, knowledgeable person present; in the case of electric cars, it is also important to note that visibly damaged, orange-coloured high-voltage cables are a warning sign and must not be touched. The free TÜV NORD used car checklist provides a structured guide, taking you step by step through the paperwork, bodywork, technical condition and test drive.

Using digital vehicle diagnostics

In addition to a visual inspection, TÜV NORD’s vehicle diagnostics service for private customers at the service centre reads out relevant vehicle data in a matter of minutes and evaluates it independently. This includes a plausibility check of the mileage (VIN check), an analysis of the fault memory, a battery check for electric vehicles, and data cleansing in accordance with data protection regulations prior to a sale. Anyone who wants to keep an eye on the vehicle’s condition themselves can use the Carly app with the appropriate OBD adapter.

For electric cars: the state of health (SoH)

In the case of second-hand electric cars, the high-voltage battery is the most significant factor affecting value – and cannot be assessed from the outside. The State of Health (SoH) provides a measurable indication of its condition. An analysis of the OBCD data analysed by TÜV NORD and Carly over the past six months shows that electric car batteries are significantly more durable than is often assumed: the median of the recorded SoH values is over 95 per cent (95.42 per cent), which is a very high level. Even for vehicles manufactured before 2019, the average SoH is still a good 83 per cent (83.06 per cent). To put this into context: a value of 100 represents a brand-new battery; values above 90 are considered very good and indicate minimal ageing; and even a range between 85 and 90 per cent still indicates a solid condition with moderate wear and tear in a used car. The value can be read via the battery check in the vehicle diagnostics system or using the Carly app.

Test drive, sales contract and handover

A thorough test drive on city streets, country roads and the motorway will reveal any noises, vibrations or gear-changing problems. All verbal assurances should be set out in writing in the sales contract; at the handover, all original documents, a handover report and the roadworthiness and emissions test certificates are essential.

Condition is key – and can be checked

Unlike the specifications or the mileage shown on paper, the technical condition of a vehicle is difficult for laypeople to assess. Much of the relevant information can be found in the vehicle documents or stored in the control units. By checking these systematically and having the data digitally read out as well, you can make a purchase on a sound basis.

“When buying a used car, it’s the actual condition of the vehicle that matters – not gut feeling. Objective, retrievable data – from mileage to the battery – gives buyers a solid basis. That’s exactly what we recommend: check first, then decide,” says Avid Avini, CEO and founder of Carly.

“Trust when buying a used car comes from transparency. Digital vehicle data complements the traditional inspection and reveals what cannot be seen from the outside. In this way, we create a reliable basis for a confident purchasing decision, particularly when it comes to electric vehicles and the assessment of their batteries,” says Hartmut Abeln, CEO of TÜV NORD Mobilität

Further assistance from TÜV NORD

For a professional assessment, the TÜV NORD AutoKaufCheck and the vehicle diagnostics service for private customers are ideal. Further practical advice – from preparation and inspection to the test drive – is summarised in the guide containing tips on buying a used car.

Outlook: Press event in October

In October, TÜV NORD and Carly will explore the topic in greater depth at a joint press event. The focus will then be on the latest findings regarding odometer tampering and fault memory analysis.

Carly is an innovative car technology company based in Munich which, since 2014, has specialised in developing technologies and solutions for vehicle repair and maintenance. By analysing meaningful data and combining it with expert advice, the company provides valuable information on the condition of vehicles.

Carly

Christopher Polzar, Chief Marketing Officer (CMO), +49 151 55700810, press@mycarly.com