FAQ towbars

Here below we can hopefully answer many of the questions frequently asked with regard to towbars

A towbar is the necessary element to ensure a safe connection between the towing vehicle and the trailer. MVG produces fixed, detachable and swiveling towbars.
How do I know that all the requirements are fulfilled so that a towbar does not have to be registered?
  • The towbar and the vehicle must have an EU licence.
  • The fitting and operation instructions for the towbar include a diagram with the clearances required in accordance with the necessary EU Guideline 94/20/EG and the ECE Regulation No. 55.

If either of these conditions is not fulfilled, a proper fitting approval will be required from the officially recognised testing authority. These rules do not apply in non-EU countries and the towbar and its installation must be noted at the official test centers. 

Do all MVG towbars have to be approved by an officially recognised authority?

No. The installation approval of the towbar is part of the vehicle authorisation in accordance with the guideline 94/20/EG and the ECE regulation No. 55, and it will be carried out at MVG by an officially recognized expert or inspector and documented accordingly in the assembly and operating instructions of the towbar.

Therefore, it is not necessary to present the vehicle to the inspecting authority, nor does the MVG towbar have to be registered separately in the car documents.

In countries that do not belong to the EU, an entry with the official test centers is also required, as the above-mentioned EU directives do not apply there. The registration can usually be processed on site by the specialist workshops in these countries. 

Important: The assembly and operating instructions of the towbar must be kept with the vehicle documents and carried by the driver at all times.

What are the given trailer and coupling loads references?
The trailer and coupling loads given refer to the towbar loads and can diverge from the values approved for the vehicle. The values approved by the vehicle manufacturer for the vehicle are stated in the vehicle documents and/or the vehicle operating manual.

As far as the trailer and coupling loads are concerned, the vehicle manufacturer’s specifications are decisive for the use of the vehicle, whereby the values of the towbar load may not be exceeded.

Can a damaged towbar be repaired?
Any repairs or alterations to the towbar are not permitted and will mean the immediate expiry of the approval. Towbars which have been damaged or in any way affected by an accident must, for product liability reasons, be completely replaced.
What does the scope of delivery of a towbar include?
The MVG scope of delivery includes all add-on components, all mounting materials, protective caps/plugs plus a detailed assembly and operating instructions for a proper fitting of the towbar.
How can I find out the maximum traction weight?
  • The maximum traction weight is the second value on the vehicle identification plate.
  • The vehicle registration documents can have appropriate remarks regarding the maximum traction weight (in kg). This defines the maximum permitted gross weight of the convoy (combination of towing vehicle and trailer). This limitation must be observed by the vehicle owner / driver.
Assembly and assembly times for the towbar
The assembly times given are non-binding reference values in minutes. These data may diverge from the given time, depending on various influences, for instance the experience of the fitter, the level of equipment or the condition of the vehicle. The assembly times given refer solely to the fitting of the respective product. Required additional work, such as the removal of the bumper or other car parts, can vary from vehicle to vehicle and can hence not be taken into account concerning assembly times. In any case, the vehicle manufacturer’s information on towing trailers in the operating manual should be observed.

Towbars and electrical kits are safety components and should only be fitted by qualified personnel!

How is the maximum traction weight calculated?
The following details serve as a general example of technical data for a vehicle:

  • Maximum permitted traction weight: 2975 kg
  • Braked trailer load: 1250 kg
  • Maximum traction weight permitted: 2025 kg
  • Max. tare weight of the towing vehicle incl. 75 kg for the driver: 1525 kg

Example 1 – Trailing load fully utilised

  • Maximum permissible traction weight: 2975 kg
  • Braked trailer load: 1250 kg
  • Maximum permissible traction weight: 1725 kg
  • Max. tare weight of the towing vehicle incl. 75 kg for the driver(Clause 14): 1525 kg
  • Remaining load capacity for the towing vehicle: 200 kg

Maximum 3 additional persons permitted

Example 2 – Towing vehicle loaded to maximum

  • Maximum permissible traction weight: 2975 kg
  • Maximum permissible laden weight: -2025 kg
  • Maximum permissible weight of trailer: 950 kg

Maximum permissible weight of trailer of theoretically1250 kg may not be utilised to the full.

Example 3 – Towing vehicle and trailer loaded to maximum

  • Permissible gross vehicle weight: 2025 kg
  • Braked trailer load: +1250 kg
  • Real maximum traction weight: 3275 kg
  • Permissible maximum traction weight -2975 kg
  • Excess traction load: 300 kg

These loading conditions are not permitted!

How is the D-value calculated in accordance with guideline 94/20/EG?
This can be calculated using the following formula*. Here an example:

  • Permissible gross vehicle weight: 2025 kg
  • Braked trailer load: 1250 kg
  • D-value of km/h: 7.582 kN

*Legend:
D = D-value of the towbar [kN]
T = Total mass of the traction vehicle [kg]
R = Total mass of the trailer [kg]
g = Gravity (9.81) [m/s2]

Can the trailing load for my vehicle be increased?
As a rule, only the vehicle manufacturer or importer can authorise an increase in the trailing load. Since the vehicles are put through various endurance tests and road trials to check their load capacity and then approved accordingly, a later increase of the trailing load for the vehicle by the manufacturer or importer will, as far as we know from experience, not be granted. Later load weight increases for vehicles to increase the trailing load are only offered by specialised business enterprises.
How can maximal/minimal trailing load of a towbar be calculated in accordance with 94/20/EG?
Example 1 – Trailer with minimal loaded vehicle

  • Max. empty weight of traction vehicle incl. 75 kg for driver: 1525 kg
  • D-value of the used km/h: 9.1 kN
  • Max. permissible trailing load of km/h: 2368 kg
  • Permissible total traction weight: 2975 kg
  • Max. empty weight of traction vehicle incl. 75 kg for driver: -1525 kg
  • Permissible maximum weight of trailer: 1450 kg
  • Braked trailer load: 1250 kg
  • The permissible trailing load of the vehicle – 1250 kg – is in this example the lowest limit and may not be exceeded.

*Legend:
D = D-value of the towbar [kN]
T = Total mass of the traction vehicle [kg]
R = Total mass of the trailer [kg]
g = Gravity (9,81) [m/s2]

Example 2 – Trailer with maximal loaded vehicle

  • Permissible total traction weight: 2025 kg
  • D-value of the used km/h: 9.1 kN
  • Max. permissible trailing load of km/h: 1711 kg
  • Permissible total traction weight: 2975 kg
  • Permissible total traction weight
  • Permissible maximum weight of trailer: 950 kg
  • Braked trailer load: 1250 kg
  • The permissible trailing load of the vehicle – 950 kg – is in this example the lowest limit and may not be exceeded.

*Legend:
D = D-value of the towbar [kN]
TLeer = TotalEmpty mass of the traction vehicle [kg]
R = Total mass of the trailer [kg]
g = Gravity (9.81) [m/s2]

Can the towbar be fitted on lowered/raised vehicles?
As a rule, YES, but a few things must be observed, as MVG only develops and manufactures towbars for serial vehicles with EU approval.

For lowered vehicles the following applies:
The clearances specified in the Guideline 94/20/EG, Annex VII, Illustration 30 and the ECE Regulation No.55, Annex 7, Illustration 25a/25b must still be warranted.

With a maximum permissible weight of the vehicle and maximum rear axle weight the towball must be positioned between 350 mm and 420 mm from the ground to the centre of the towball.

For raised vehicles the following applies:
An alteration to the serial towbars is not possible for reasons of EG/ECE approvals. If the towball of the towbar on the raised vehicle is so high that proper use of the trailer is not warranted, the trailer must be adjusted in accordance with the technical possibilities (e.g. a height adjustable towbar) but still keeping in line with the technical specifications and guidelines.

If the adjustment of the trailer is not possible then the MVG towbar cannot be used. In such a case a towbar from the accessories for off-road vehicles can sometimes help.

What happens if the key for the removable MVG ball hitch gets lost or is broken?
We have replacement keys available for removable MVG ball hitches. When ordering replacement keys, please give the three-digit key number and the MVG model or MVG system of your towbar. The three-digit key number can be found on the lock cylinder of the removable MVG ball hitch.

– To be on the safe side, the key number should be noted in the operation manual of the removable MVG ball hitch. –

How can you tell if a car is allowed to tow a trailer?
Before fitting a tow bar it is very important to check whether the vehicle is actually approved for trailer operation. This can be seen on the vehicle data plate. If a value is stated in the second line of the technically permissible weights, this value constitutes the total weight allowed and specifies whether a trailer may be towed and with which weight. You will find where the data plate of the vehicle is located, in the user manual of the vehicle.

You will also find additional important information for trailer operation in the registration certificate part 1 (vehicle documents). Here are the values O1 and O2 as to the braked and unbraked towing capacity technically authorized are specified. If no values are given here, then the vehicle is not approved for towing.

What material are used to make the MVG ball-rods?
The ball-rods from MVG are made of forged steel (material ST 52-3N [S355J2 + N]).
Does the vehicle warranty expire due to the subsequent installation of a trailer hitch?
No. The warranty of the vehicle will not be affected when a trailer hitch is retrofitted. However, you should make sure that the towbar is properly installed, we recommend the installation by the hand of a specialist workshop.
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Mail info@mvg-ahk.de
Phone +49 (0) 2403 / 7902-60
Fax +49 (0) 2403 / 7902-99