It's important to know that increasing the weight involves two parties. On one side, AL-KO VT as the chassis manufacturer, who will explain what is technically possible for the running gear. On the other, the manufacturer of your caravan, who must approve the level of weight upgrade that the bodywork can handle in everyday use. More information is available in the section “Necessary documents for a weight upgrade”.

The payload is calculated as the difference between the permissible gross weight and the unladen weight: Permissible gross weight – unladen weight = payload

As the unladen weight stated in the registration certificate does not always correspond to the actual unladen weight, it is always advisable to weigh your caravan beforehand. If your caravan has an AL-KO VT chassis – as is the case with almost all manufacturers nowadays – we can offer you individual solutions and possibilities to allow additional weight to be loaded into your caravan, enabling you to set off on your journey without stress. In this guide you will find out which measures are generally available and what the key considerations are.

There are a number of ways to achieve your desired weight upgrade – but not every variant is possible for every caravan. The measures suitable for your case depend on the interplay between the current weight, required additional weight and the specification of the running gear components of the caravan. Generally, the greater the difference between the current and the intended permissible gross weight, the more parts or running gear components will need to be replaced. That is why costs for the different types of weight upgrades can vary considerably, and even the price for the same type of upgrade can change significantly depending on the starting situation.

To determine which procedure will get you to your desired objective, we always start each enquiry with the weight upgrade checklist for AL-KO VT chassis. This checklist is the essential basis for further advice and forms the starting point for all further steps towards increasing your caravan’s gross weight.

On this checklist, you will enter key technical data for your caravan. Our technical team will use these details to identify which of your caravan’s components already have adequate capacity for the desired extra load, and which will need to be upgraded.

We will need the following details from you:

• Caravan manufacturer
• Caravan type/caravan model
• Vehicle identification number
• Chassis drawing number (chassis number)
• Information on registration and weight
• Manufacturer’s approval (certificate of no objection)
• Technical data for the axle, wheel brake, overrun device, towing connection, tyre size

Why is the checklist so important? As the chassis manufacturer, AL-KO VT cannot simply tell from the caravan type which individual components with which technical properties your caravan is made up of. However, this information is vital for answering questions on weight and therefore the payload upgrade of your caravan. The way the individual components interact determines the type of upgrade suitable for your vehicle.

Documentary weight upgrade

For some caravans, it is possible to carry out what is known as a ‘documentary weight upgrade’. This upgrade takes place solely on paper – specifically in the vehicle documents. It does not require any technical modifications to the chassis, but is processed entirely through the manufacturer of the caravan. The manufacturer checks for what overall mass the running gear of your caravan is actually rated. This is then confirmed by means of a certificate of no objection and a new type plate is issued. Afterwards you present the caravan at an inspection body such as TÜV or DEKRA for inspection and approval, and finally, you have the new permissible gross weight entered into the vehicle documents at the registration office.

Disadvantages: This type of upgrade is only possible in rare cases and in most instances only results in a slight increase in maximum weight or payload.

The cost of a documentary weight upgrade starts from around €150, depending on whether a brake calculation is still required from the chassis manufacturer.

Replacement of suspension elements in the axles

First, some basics about axle suspension: If the caravan is to cope with a higher load, it is ultimately the axles that must bear this weight. The axles of the caravan contain the suspension, which is made up of rubber cords. Each axle has three rubber cords per axle side. These differ in length and hardness depending on caravan type. If too much weight is placed on axles not designed for it, the rubber cords will become oval over time and the axle swing arm will then be misaligned in the axle tube. Visible consequences of overloading include worn tyres on the outside edge, which can subsequently lead to a tyre burst – something you certainly want to avoid!

To repair or avoid damage caused by overloading the axle, we are happy to check whether replacing the suspension elements with a stiffer version could be a suitable option for you.

With this type of weight upgrade, the axles of the caravan are removed and the rubber cords taken out. Based on the weight increase, our specialists calculate the correct length and hardness required for the new rubber cords to bear the increased axle load. After the new axle rubbers are professionally fitted, tracking and camber are adjusted. With this type of upgrade, an increase of up to 200 kilograms is possible.

Depending on your specific situation and desired weight, it may be necessary for a weight upgrade to replace running gear components. This may include the entire axle(s), brakes, shock absorbers, overrun device or frame parts. We also use the checklist to determine which parts of your caravan can already support the extra weight, and which must be replaced.

In addition to the information gathered from the checklist, extra factors may need to be checked when considering this type of upgrade. These include, for example, the presence of a GRP floor (glass-fibre reinforced plastic), a stabiliser coupling, an ATC, or a manoeuvring system, as well as the load capacity of tyres and wheels, the available space in the wheel arch, or a 100 km/h approval, since this extra equipment also affects the overall interaction of all components. AL-KO VT reserves the right to carry out upgrades exclusively in its own customer centres.

With the replacement of the relevant chassis components, the permissible gross weight can be increased by up to 300 kilograms.

The base price for this type of upgrade starts at €1,800, but the individual configuration of the components for each running gear setup is decisive. As a result, costs can vary considerably.

Replacing the complete chassis

To increase the permissible gross weight of your caravan, it may be necessary to replace the entire chassis. This is the case if the replacement of individual components is not sufficient for a meaningful weight increase. Here, as with replacement of chassis components, different additional equipment features are checked (GRP floor, stabiliser coupling, ATC, manoeuvring aid, etc.).

When replacing the chassis, the existing chassis is separated from the body and replaced in its entirety with a new one that can handle the specified load. With this type of upgrade, an increase of up to 500 kilograms is possible.

The starting price for replacing the chassis is €5,800, and for this type of upgrade too, actual pricing depends significantly on the individual circumstances.

Overview of the different types of upgrades and their costs

• Documentary upgrade, possible increase 100 to 200 kg, cost approx. €180
• Replacement of axle rubbers, possible increase 100 to 200 kg, cost approx. €500
• Replacement of running gear components, possible increase 100 to 200 kg, cost approx. €1,800
• Replacement of complete running gear, possible increase 100 to 200 kg, cost approx. €4,800

Necessary documents for a weight upgrade

You now know which upgrade options might generally be available. Now is the time to contact your caravan manufacturer to clarify how much additional weight your model can be approved for.

For this you apply for a so-called certificate of no objection. With this, the manufacturer confirms that the body of your caravan will also be rated for the new, higher permissible gross weight after the upgrade and can be put into circulation. In almost all cases, the caravan’s type plate will also need to be replaced – this too will be issued by the manufacturer with the new information.

These documents are not only necessary for carrying out the upgrade at AL-KO VT, but are also mandatory for the subsequent approval of the upgrade at an appropriate vehicle testing centre, such as TÜV or DEKRA. As a final step, you must have the new weight details entered in the vehicle documents (registration certificate) by the registration office.

What else to consider when upgrading the weight

Although a weight upgrade only changes the permissible gross weight of your caravan initially, this has effects on the entire vehicle combination.

• Towing vehicle: Please check whether your towing vehicle is also rated for the future weight of your caravan.
• Speed limit: The increased weight of the caravan may result in the loss of the 100 km/h approval if, after the upgrade, the trailer is heavier than the towing vehicle. This would mean a speed limit of 80 km/h on German motorways. Locally, different regulations will apply abroad.
• Driving licence: Check your current driving licence category. If the combination exceeds 3.5 tonnes gross weight due to the upgrade, you will need to upgrade to at least category BE.

How much does a caravan weight upgrade cost? Are there flat-rate offers?

The cost of a weight upgrade cannot be stated as a flat rate. The main reason is the individuality of each caravan. The interaction of all the components in your caravan determines the type of upgrade and the resulting costs, so there are no flat-rate offers. That’s why the checklist is essential for calculating the upgrade.

Can you increase the weight rating of a caravan retrospectively?

Yes, this is possible for very many models. Again, the specific starting point for your vehicle is crucial, which we identify with our checklist.

Who carries out the weight upgrade?

A caravan weight upgrade is usually carried out by the chassis manufacturer after checking the requirements for the specific vehicle. An exception is the so-called documentary upgrade, which requires no technical changes. This is inspected by TÜV and then entered in the vehicle documents by the registration office.

Where can I have my caravan weight upgrade carried out?

AL-KO VT reserves the right to carry out weight upgrades exclusively at its own customer centres. As the chassis manufacturer, we have complete expertise and are able to competently assess which individual solutions are available for each running gear set-up. In addition, in the event of unexpected issues, we can access the full expertise of our development department and use specialist technical equipment.

How long does the weight upgrade process take, from enquiry to completion?

The timescale is as individual as the cost. Depending on which type of upgrade is required for your chosen weight, we will determine which components need to be replaced. The delivery time of these parts is a key factor we cannot influence. Therefore, we strongly recommend that you do not leave your upgrade until just before you are due to go on holiday. However, we assure you that we will carry out the entire process as efficiently as possible.

Can I increase my caravan’s permissible gross weight without limit?

No, this is unfortunately not possible, as at some point the body would no longer withstand the weight. Your caravan’s manufacturer will be able to tell you how much additional weight can be approved for your model.

Michael Duckek heads up the customer centre at the Kötz site and is an expert when it comes to upgrading weight. That’s why he was a guest on the podcast of our partner CamperStyle. In the episode