There are a few options available for you if you need to carry loads that are too big to fit in your car, the safest of which are to use a trailer with suitable towing accessories, or to have a set of roof racks. Whatever the carrying method though, there are also a few other things to consider such as weight distribution, the method used for securing the load, wind noise and aerodynamics and other general safety concerns.

Trailers

The most obvious, versatile and stable method for carrying external loads with your car, is to use a trailer and the relevant trailer accessories. We have covered trailers in more detail in other DIY articles, but the information here that pertains to loads, straps and more is still very much relevant to the use of trailers too.

Roof Racks

Before using roof racks, you should check the weight that can be safely carried on your vehicle's roof, as well as the load limit of the roof racks themselves. You may also require specialised rack accessories to suit the type of load you intend to carry - for example, to carry a kayak, you will inevitably need a set of kayak cradles. There is a massive variety when it comes to roof racks and the many different roof rack accessories that can be fitted - from roof rack platforms and trays and storage cases to the kayak cradles and bike carriers - be sure to consult an expert for advice on what setup will best suit your needs. If you've already got your setup sorted, we have a handy DIY on how to install roof racks, accessories and cages.

Remember that the more weight you carry on top of your car, the less you can carry inside it since it all adds to the total weight that you are carrying. Exceeding the manufacturer's limits can put a strain on your car's suspension to the degree that your handling and therefore your safety can be severely compromised.

Roof racks also increase wind resistance and buffeting - particularly when carrying loads - and so they can negatively impact your fuel economy to a fairly noticeable degree. For this reason, you should consider driving slower if you are carrying a load on your roof, and perhaps remove the racks if you aren't.

Straps & Tie Downs

When you are carrying any external load - be it on roof racks, the bed of a ute, or even in a trailer - it is important to consider how you are going to secure it. You'll need to do so in a manner that is safe and unable to come loose accidentally, but that you are going to be able to remove again once you get the load where it's going.

One of the most common methods is the use of ratcheting tie down straps, and for a good reason. These straps are adjustable and strong, and fairly easy to use, once you get the hang of how to thread them, so they can be used in almost any situation where you need to secure an external load. Another common method for securing lighter loads is the use of elastic straps or bungees - these are useful for securing things inside trailer or ute beds to eliminate unwanted movement, though they should absolutely never be used to secure a load to your roof racks. Similar to bungee cords, cargo nets can be used to keep looser loads from accidentally escaping from your trailer or ute tray, and yet again, these are unsuitable for tying things down to your roof racks. Most nets come in predetermined sizes and are usually made from sturdy nylon, though there are some stretchable elastic options too.

Whatever the method for securing your load, it is imperative that it be just that - secure. Be sure to familiarise yourself with the correct sorts of knots, loops and tying methods required to keep your cargo firmly in place until you need to free it, and always attach your tie down straps to sturdy and appropriate locations.

Weight Distribution

One of the more important things to consider when carrying external loads is how the weight is going to be distributed. Your vehicle will handle differently with different loads on, in or being towed by it, and so it's important to get a basic idea of what to expect with each, as well as how to correctly place your load in such a way that it will minimise the effect on your vehicle's handling and safety.

One of the most important things to get right is proper weight distribution in trailers. As a rule, you should always aim to have the majority of the weight located above the trailer's axle. If it is too far back, the weight of the load will compromise your car's ability to control the trailer, and it can cause fishtailing and other unpredictable and outright dangerous behaviour. If the load is too far forward, then it can place undue stress on the tow hitch and coupling, as well as lift the front wheels of your vehicle off the road somewhat - which can have an adverse effect on your steering.

Weight distribution in ute beds and on roof racks is slightly less critical than with trailer loads but is still essential to get right in order maximise safety and to avoid damage to your load or your car.

As far as roof racks go, the main thing to consider besides the actual weight limit of the racks, is how the load will be dispersed over them. You'll want the heaviest parts to be somewhat central, but more importantly carried by the actual racks instead of either suspended in the gaps between, or worse - sagging onto your roof.

Always be sure that when you add or remove stuff to an existing load, that you shuffle things around to maintain an ideal distribution of weight too.

Long load flags and other markers In most places, there are sensible limits to how much a load can legally extend from your car or trailer, and when one does extend beyond the limits of your vehicle, then it should be marked in such a way as to minimise the danger to other motorists. For this reason, you should be sure to read up on the laws in your region before carrying anything excessively long or wide on your roof racks or in a trailer. If you do carry a load that extends beyond specific limits set by your state or country, then you'll need to attach markers of some sort. Usually, these will be in the form of long load flags, or as reflective marking strips. Additionally, if you are carrying an overhanging load at night, then you might also be required to attach lighting to the load - be sure to check with your state or national laws in order to see which requirements you need to meet and in which circumstances.

Wind Noise

The final thing to consider when carrying external loads is just how much additional noise you are willing to put up with. A simple web search will reveal countless queries as to how to solve the problem of wind noise, including actual university studies done to try and find the absolute best solution possible! Luckily, for those of us without government funding and university research teams at our disposal there are still a few different ways that you can reduce the noise - from wind deflectors and fairings to specialised straps and simple methods for securing your loads - you should be able to find a solution that will suit your budget.