What are the types of inspection

Fixed and flexible maintenance intervals

Regular maintenance is essential for the operational and road safety of a vehicle. We explain the advantages and disadvantages of fixed and flexible maintenance intervals and how the service at BMW, Audi, Mercedes, Mini, VW and Co. works.

Fixed versus flexible maintenance interval

There is no such thing as a vehicle that does not require maintenance. For many assemblies and operating materials in cars, regular checks and renewals are indispensable in order to ensure the operational and road safety of the vehicle. Their wear and tear depends primarily on the operating conditions and vehicle manufacturers adjust the maintenance specifications as a compromise to normal, average conditions. Fixed maintenance intervals can therefore be advantageous for vehicles with low annual mileage and / or gentle driving style. Conversely, a flexible interval can be better in the case of above-average driving performance or extreme operating conditions.

Advanced vehicle electronics - such as sensors and software - can detect wear and tear on wear parts and thus enable needs-based maintenance calls. With this partial flexibilization of maintenance, fewer visits to the workshop are not necessarily to be expected, since, for example, brake fluid ages regardless of mileage and operating conditions and has to be replaced at regular intervals. They can still pay off for the customer because, for example, brake pads without sufficient reserves are not replaced at a fixed date as a precaution, but can be used up to the wear limit. Only then does the request appear to have a change made. The same applies to the engine oil. Maintenance calls based on requirements can therefore help to save resources.

The maintenance systems from Audi, BMW, Mercedes, Mini, VW and Co.

Since the 2000 model year, Audi customers have been able to choose between fixed and flexible service or maintenance intervals (long-life service). The vehicles are delivered from the factory with a flexible oil service interval. The oil change requests are made after 15,000 to 30,000 kilometers or after one to two years. To measure oil aging, the on-board computer takes into account the individual operating conditions (fuel consumption, cold starts, oil level, oil temperatures, etc.). With the optional fixed oil service interval, the oil change is due every year or every 15,000 kilometers - whichever is reached first. Vehicles with a flexible interval require a long-life oil, for petrol vehicles with a fixed interval you can use an alternative engine oil.

The service events "engine oil" and "inspection" are controlled and displayed separately for vehicles from around model year 2008 onwards, unless they occur at the same time. The driver receives the information via the service interval display in the cockpit and via the multimedia interface (MMI). Completed maintenance work is documented in the service plan (logbook) and in the Audi ELSA workshop system, to which only Audi authorized dealers have access. Inspection work is subject to a fixed service interval and is generally required every 30,000 kilometers or every two years (whichever is reached first). From around model year 2008, mileage-dependent service events (such as transmission oil changes) and time-dependent service events (such as brake fluid changes) can also be controlled with the inspection channel. As a rule, however, these events coincide with the inspection.

The BMW Group has had a flexible service and maintenance interval since 1982. The oil change requests are to be expected at around 30,000 kilometers or after around two years. The on-board computer takes into account the individual operating conditions (fuel consumption, temperature and time) to measure oil aging. The driver receives information on due maintenance via a display in the cockpit and, in the case of newer models, via a smartphone app and - depending on the vehicle equipment and customer approval - from the dealer.

Inspections are due every four years or 60,000 kilometers, and individual work can be called up from time to time, such as changing the brake pads. Completed maintenance work is entered by the authorized workshop in the classic logbook and, in the case of newer models, in the digital service book. The customer and persons authorized by him have read access to the digital service booklet. In addition, authorized independent workshops are allowed to make maintenance entries in the digital service booklet.

For Ford models from current production, fixed maintenance intervals are specified: every 20,000 kilometers or every year (due when the first value is reached). Exceptions: Different criteria apply to the Tourneo, Transit and Ranger models. In addition to the inspection / service, an oil change is always due during the maintenance appointment. Exceptions: Some models with bio-ethanol operation require an oil change every 10,000 kilometers and the Mondeo, S-MAX and Galaxy models have a display for flexible oil change when equipped with a Euro 6 TDCi diesel. The on-board computer takes into account the number of starts, the kilometers driven, the running time, the filling level and other factors to measure the oil aging.

The manufacturer's workshops document completed maintenance work in the service booklet (log book) and in the Ford DSN system (digital service certificate). When making entries in the DSN system, the customer receives a printout. Independent workshops can get free access to the DSN. As part of the Ford mobility platform “FordPass”, customers should also be able to access the information themselves.

Honda has completely abolished the fixed maintenance periods. The first models with flexible or automatic maintenance intervals were Jazz and Accord from model year 2009. All models now have this system, which evaluates mileage, time and driving cycles. On average, a Honda should be called to the workshop after a year and 20,000 kilometers through a display in the cockpit. The calls for inspection and oil change can also appear individually. Optionally, the maintenance interval system can also be deactivated. Inspection and oil change are then always required after a year or 20,000 kilometers (due when the first value is reached).

Many current Hyundai models have a maintenance interval of two years or 30,000 kilometers, whichever comes first. The interval length depends on the model and engine, which is why no standardization is possible. An inspection reminder can be set manually in the on-board computer. The inspection work and the oil change take place at the same time. The maintenance work carried out is documented in writing in the guarantee and service booklet. The introduction of a digital service booklet is currently not planned.

All current models from Kia have a fixed maintenance interval. Most have to go to the workshop for an inspection and an oil change after 30,000 kilometers or 24 months (due when the first value is reached). For Picanto, Venga petrol and Soul with petrol and electric motors, maintenance is due every 15,000 kilometers or 12 months (when the first value is reached). Extra oil changes - every 12 months - are required for the cee'd with a 1.4 MPI petrol engine. For the current cee'd there is a service interval display in the instrument cluster, as is the case with all current models from the Kia Rio. Completed maintenance work is entered in the service book.

Current Mazda models have to be serviced and oil changed at the latest every 20,000 kilometers or after 12 months at the latest. In addition, the current models with SKYACTIV-D diesel engines from the Mazda2, Mazda CX-3, Mazda CX-5 and Mazda6 series also have a flexible oil change indicator. This calculates the remaining service life of the engine oil based on the engine operating conditions. The remaining service life (in percent) can be called up by the customer via the MZD Connect system with the active display of the flexible oil change interval. When the wear limit of the engine oil is reached, the wrench indicator light that lights up in the instrument cluster informs the customer that an oil change is due. The aging or remaining useful life of the engine oil is determined from a corresponding algorithm of the engine control.

As early as 2005, Mazda was one of the first automobile manufacturers to introduce a digital checkbook, the Digital Service Proof (DSR). The DSR stores and documents all maintenance work and any additional work that is carried out on Mazda vehicles. All important documents relating to the maintenance history are available to the customer in the My Mazda app. Independent workshops can use the DRS free of charge after registering in the Mazda portal and after providing evidence that it is a vehicle workshop operation and enter the maintenance work that has been carried out.

All Mercedes-Benz passenger car models have a fixed maintenance interval: You must always go to the workshop for an inspection and an oil change after 25,000 kilometers or at the latest after 12 months. AMG vehicles or G models have to be serviced after a maximum of 20,000 kilometers or one year. As part of a service consultation on the vehicle, the customer receives a detailed list of individual maintenance items, such as information about service A or B, the additional work that is due and the oils used.

Currently in 133 countries, including in Germany, the maintenance work carried out on Mercedes-Benz cars and Smarts is documented in the digital service book. In Germany, this has been possible for cars since 2008 (Smart from 453 series). The customer is informed of the next service appointment by means of the service interval display in the cockpit. Customers who have registered via the “Mercedes me” Internet portal can also view the respective maintenance requirements via a smartphone app.

The current models from Mitsubishi have to be inspected and oil changed in the workshop every 20,000 kilometers or after 12 months at the latest. The customers are informed about the due maintenance date by means of a display in the cockpit. Completed maintenance work is documented in the service book (log book).

Most current Nissan models have to be serviced and oil changed every 20,000 kilometers (petrol) or 30,000 kilometers (diesel) or after 12 months at the latest. The customers are informed of the next upcoming maintenance date by means of a display in the cockpit. Completed maintenance work is documented in the service book (log book).

Current Opel models have a fixed maintenance interval: They have to go to the workshop for an inspection and an oil change after 30,000 kilometers or at the latest after 12 months. Flexible parameters for the wear and tear of the engine oil are stored. The driver receives the maintenance call via a display in the cockpit. The oil service life can be called up using the “myOpel” smartphone app. Depending on the model, different work volumes - intermediate or main inspection - are specified at the maintenance appointment. Completed maintenance work is documented in the service booklet (log book). Electronic findings reports can be viewed when registering in "myOpel".

Peugeot / Citroën / DS (PSA group)

The vast majority of Peugeot / Citroën / DS vehicles have fixed maintenance intervals. Only for vehicles with BlueHDI Euro6 diesel engines are there flexible maintenance intervals or the maintenance intervals can change from "normal use" to "difficult use" if the system detects the corresponding operating conditions. The variable intervals are merely a change to the information that applies to difficult use of the vehicle. Maintenance is therefore either carried out at the normal intervals or changes to the intervals for difficult operating conditions when the system detects the corresponding conditions. Relevant factors are, for example, soot or fuel. Service work and oil change are always summarized. The fixed maintenance differs depending on the model and engine and takes place between 15,000 and 30,000 kilometers or at the latest after one year under normal operating conditions.

In addition to the paper maintenance booklet, Citroën and DS customers have the option of having a digital maintenance booklet. This requires that the vehicle is equipped with BTA (this is a control unit with a factory-installed SIM card for the emergency call or breakdown call function) and that the customer has a so-called My-Citroën account and has booked the Connect Pack Monitoring option. This option will soon be offered to Peugeot customers. If the customer has booked the Citroën / DS Connect Pack Monitoring option, he can also view the maintenance booklet in his “My Citroën account” using a smartphone, tablet or PC. However, the digital maintenance booklet does not replace the paper maintenance booklet and does not serve as proof of maintenance or as a maintenance reminder. Independent workshops cannot receive direct write authorization for the digital maintenance booklet. However, the maintenance booklet is changed if the maintenance indicator has been reset in a workshop.

Most current models from Renault have to be inspected in the workshop every 30,000 kilometers or after 12 months at the latest. Customers are generally informed of the next upcoming maintenance date by means of a display in the cockpit. In addition, an extra request to change the oil may appear on the display if the oil is no longer in working order. Completed maintenance work is documented in the service booklet (log book).

Since the 2013 model year, Skoda customers have basically been able to choose between fixed and flexible service and maintenance intervals. The service call is based on the time and can usually be expected after one year. The on-board computer takes into account the individual operating conditions (such as time, oil level, oil temperatures, etc.) to measure oil aging. With the fixed maintenance interval, the oil change is due every year or every 15,000 kilometers (when the first value is reached). The Citigo model only has a fixed maintenance and oil change interval. The engine oil differs in the respective standard depending on the underlying interval (fixed or flexible).

The driver receives information on due maintenance via a display in the cockpit. Completed maintenance work is documented in the digital service plan, which Skoda dealerships and independent workshops can write to. In addition, after the maintenance, the customer receives written evidence to include in the logbook.

Current models from Suzuki with a petrol engine have a fixed maintenance interval: You have to go to the workshop for an inspection and an oil change after 15,000 or 20,000 kilometers - depending on the model - or at the latest after 12 months. With Vitara and Swift (from model year 2014, except Swift Sport), the driver receives a maintenance call via a display in the cockpit. Current models with a diesel engine and DPF have a flexible oil change indicator. The calculation of the flexible oil change intervals is based on the oil dilution that occurs when the diesel particulate filter is regenerated. With an average driving style, the oil change request appears on the display in the instrument cluster after around 20,000 to 30,000 kilometers. Inspection work and oil changes are also due individually. There is no choice between flexible and fixed maintenance intervals. Completed maintenance work is documented in the service booklet (log book).

There is also a trend towards flexible intervals at Toyota: The flexible maintenance indicator (OMMS) has been available since 2005 on models with 1.6 and 2.0 liter diesel engines. The engine control unit calculates the soot load in the engine oil, and thus the required change time, from the average values ​​of the engine speeds run, the fuel injection and the intake air quantities. With an average driving style, the maintenance call via a display in the instrument cluster comes after about a year or after 15,000 to 20,000 kilometers. There is no choice between flexible and fixed maintenance intervals. All other current Toyota models with petrol engines and 2.8 liter diesel have a fixed maintenance interval. You have to go to the workshop for an inspection and an oil change every 15,000 kilometers or after 12 months at the latest. The driver receives the maintenance call via a display in the cockpit. Completed maintenance work is documented in the service booklet (log book).

For Volvo cars from current production, fixed maintenance intervals are generally specified: After 30,000 kilometers or one year (due when the first value is reached). During the maintenance appointment, in addition to the inspection / service, the engine oil change is always due. The driver receives the maintenance call via a display in the cockpit. Completed maintenance work is documented in the service book (log book).

At VW, customers have had a flexible service and maintenance interval (LongLife Service) for almost all models since the 2000 model year. With these, oil change requests are to be expected after 15,000 to 30,000 kilometers or after one to two years.In addition, a higher-quality engine oil according to the VW standard is a requirement. The on-board computer takes into account the individual operating conditions (fuel consumption, cold starts, oil level, oil temperature, engine speed, distance traveled, etc.) to measure oil aging. Instead of the flexible maintenance interval, the customer can also switch to a fixed maintenance interval.

Some models are always delivered with fixed 15,000-kilometer maintenance intervals, including, for example, the up !, GTE, TGI and flex-fuel engines. For fixed intervals, a (cheaper) engine oil according to VW standards is sufficient. The driver receives information about due maintenance via the service interval display (SIA) in the cockpit and, in the case of models of the new so-called modular transverse matrix (e.g. current Golf, Passat, etc.) via the radio control unit (HMI).

Completed maintenance work is documented in the logbook and in the VW workshop system ELSA / ERWIN. A service sticker is also used on the door pillar up to model year 2014. Maintenance instructions via smartphone / tablet are in preparation. A digital service plan with writing and reading options by the customer or the contracted independent workshop is planned. The first inspection is generally required after 30,000 kilometers or two years (when the first value is reached). Then every 30,000 kilometers or always after a year (when the first value is reached). With a flexible interval, the oil change does not take place until after two years or 30,000 kilometers at the latest, but the car still has to go to the workshop annually for an inspection.

That happens when a car is serviced

For technical or economic reasons, some components do not survive the entire service life of a vehicle. These are parts that lose their material (e.g. brake pads, tires) or age and thus become unusable (e.g. starter batteries, windshield wiper rubbers). If the first-mentioned parts do not become unusable due to wear, this can often also occur due to aging (e.g. in the case of tires). Worn parts are replaced during maintenance work. In the case of parts or equipment that are not subject to any obvious wear and tear, but lose their functionality due to chemical or physical influences, the vehicle manufacturers prescribe a renewal after a certain mileage or service life. These include, for example, coolants, hydraulic fluids and lubricants, but also drive and toothed belts.

The manufacturer specifies exactly what is renewed during maintenance. For example, conventional water-binding brake fluids have to be replaced mainly because they absorb water from the ambient air. That means: after a fixed period of time. The mileage and conditions of use of the vehicle have no influence on this. The usability of the motor oil, on the other hand, decreases primarily due to chemical and physical influences, among other things. through the entry of residues from engine combustion - such as fuel, soot, acidic combustion condensates - and temperature-dependent oxidative processes. The aging of the engine oil therefore mainly depends on the operating conditions.

The usual scope of maintenance work includes the replacement of used operating fluids and wear parts as well as the functional check of important assemblies. In addition, the vehicle is examined for damage that may have occurred to tires, brake hoses or the body as a result of external influences or unfavorable operating conditions. If necessary, the vehicle manufacturer will also carry out free improvements ("field campaign") in the case of known weaknesses that are not relevant to security. Unfortunately, the car owner is usually not informed about this.

Wear parts and supplies that usually have to be serviced and their dependency on mileage, time and operating conditions:

Wear parts and supplies

Renewal depending on:

Axle and gear oil

Mileage

AdBlue / DPF additive

Mileage, operating conditions

Drive belt

Mileage, time

Radio central locking battery

time

Lighting / electrical equipment

time

Brake pads

Mileage, operating conditions

brake fluid

time

Fault memory

Mileage, time, operating conditions

Cabin air filter

Mileage, time

Body / chassis

time

Fuel filter

Mileage

Antifreeze

time

Engine air filter

Mileage

Engine oil

Mileage, time, operating conditions

tires

Mileage, time, operating conditions

Tire sealant

time

windshield wipers

Mileage, time

Starter battery

Time, operating conditions

Timing belt

Mileage, time

Spark plugs

Mileage

Wear parts and supplies: state of the art and outlook

Axle and gear oils are subject to loads that primarily depend on the design and type of gearbox. In some vehicles, oil changes are planned after higher mileage - after around 100,000 kilometers. Even with further developed lubricants and gears, it is unlikely that oil changes can be saved in all applications in the future.

AdBlue® already has to be refilled in current vehicle models not only during the maintenance appointments, but also in between. Stricter exhaust gas requirements for diesel vehicles also lead to higher AdBlue consumption, which means that there is also greater demand. The range is growing, filling stations are also installing dispensing systems for AdBlue. The reducing agent no longer has to be bought in disposable plastic containers, but can be refueled yourself, which is cheaper and more waste-saving.

Drive belts and toothed belts

Drive belts and toothed belts for auxiliary units are maintenance-free in current vehicles and now have a long change interval - usually over 100,000 kilometers. With better materials and constructions, it is conceivable that a change will no longer be necessary in the future.

Batteries for the radio central locking system

The batteries for the radio central locking are inexpensive standard parts. Their useful life depends on the self-discharge, capacity and energy consumption of the transmitter and can be up to four years. Vehicle manufacturers strive for low-cost solutions and small designs for radio transmitters, which is why longer battery replacement cycles are not to be expected here. In the future, the remote control key could also lose its importance as a separate component - if the car is unlocked using a smartphone.

The lighting system of current vehicles - especially those with incandescent lamp technology - should be checked regularly because defects are possible at any time. More and more cars have a lamp failure check as standard. This indicates when a lamp is defective. This occurs particularly rarely with headlights and lights with light-emitting diodes (LED), which often last as long as the entire car and are therefore often not interchangeable. In the (rare) case of a defect, however, the entire unit must be replaced, which can be very expensive.

Brake pads and discs

The wear and tear on brake pads and brake discs is highly dependent on the driving style. When driving normally, it is common to change the disc brake pads after around 80,000 kilometers. In difficult operating conditions - for example when driving with a trailer - considerably higher wear is possible, which is why a check during regular maintenance is essential. More and more cars are therefore equipped with a wear control: It lights up when a brake pad on the front axle is close to the wear limit. Then you should drive to the workshop within a few hundred kilometers.

In the case of a regular change, only the quality of brake fluid that the vehicle manufacturer specifies may be used. Mixing is prohibited. The usual glycol ether-based brake fluids are hygroscopic, so they attract water. With increasing water absorption, the properties of the brake fluid deteriorate: the boiling point decreases, the viscosity increases and corrosion problems can occur on the inner parts of the brake system. A regular change of the brake fluid - usually every two years (for some new cars for the first time after three years, but then also every two years) - is therefore essential.

The replacement of the traditional glycol ether-based brake fluids with other substances - such as silicone or mineral oils - has been called for time and again in order to reduce maintenance and thus save costs, because they do not attract water. Disadvantages of these products: They can be compressed more (means a spongy pressure point) and have poorer lubricating properties, which is why they are less suitable for current braking systems. What is critical with silicone and mineral oil fluids is the formation of local water droplets, which expand into vapor bubbles when heated to over 100 degrees Celsius and freeze when cooled below zero degrees Celsius (source: Bosch Kraftfahrtechnisches Taschenbuch).

Error memory of the control units

The fault memories of the electronic control units are helpful for finding the cause of acute problems. In addition, irregularities are sometimes saved here before a component fails completely. Reading out the fault memory during regular maintenance is therefore important for the operational safety of the car.

Air filters protect the engine and vehicle occupants from dust particles from the atmosphere. Your storage capacity is limited. Their loading depends on the environmental and operating conditions. Therefore, they have to be checked regularly and renewed if necessary. Cabin air filters should usually be changed every year and engine air filters according to the manufacturer's instructions. An extension of the change intervals through further technological development seems rather unlikely.

The usability of the engine oil decreases due to chemical and physical influences, including. through the entry of residues from engine combustion - such as fuel, soot, acidic combustion condensates - and temperature-dependent oxidative processes. Due to increasing engine design loads - such as downsizing - or fuels with higher biological proportions - such as alcohol or biodiesel - a shortening of the oil change intervals can be expected in the future. Some vehicle manufacturers therefore decouple the oil change from other maintenance work.

Tires are subject to aging and use-related wear and tear. Ultraviolet radiation and ozone cause aging, wear and tear is caused by abrasion on the road. The usual usability of car tires is therefore between one and eight years and is up to 60,000 kilometers.

Tire sealants lose their usability due to oxidation and other chemical reactions. They must be replaced after about five years or the use-by date printed on them.

The rubber lips of windshield wipers in particular are subject to aging and wear effects. Ultraviolet radiation and ozone cause aging, while wear is caused by friction on the window. The usual usability is about a year.

The starter battery loses storage capacity over time due to various chemical and physical effects. Therefore, it is now considered a wear part. An exchange is usually due after three to six years.

Spark plugs wear out depending on the type, material and fuel. In the 1980s, they were replaced after around 15,000 kilometers, with today's versions the replacement interval is around 60,000 kilometers.

Car maintenance in the future

For several years there have been vehicles that send a maintenance or repair requirement from the car via mobile phone directly to the nearest contractual partner via the manufacturer and immediately provide the owner with suggested dates.

All information on the care, repair and maintenance of vehicles can be found here

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