Tow Bars and Tow Cars: Breaking the stigma

In certain countries, such as the UK, there is a certain stigma and a number of myths surround tow cars or vehicles with tow bars fitted, which depending on one's viewpoint, either increases or decreases the appeal of a used vehicle. Jump across the pond to places like America, and you will struggle to find an SUV or pickup without a tow bar. But, what should you actually believe?

This article aims to break down what actually happens to a vehicle when you tow.

What is a tow bar?

A tow bar is a sturdy metal frame fitted to the car's chassis, which allows you to tow via a tow hitch or ball. Most trailers and caravans are fitted with a tow ball, and drivers can legally tow up to 3.5 tonnes from their vehicle with a braked trailer or caravan.

The tow bar frames are designed to spread any forces across the car's chassis, much like the car itself is designed to.

When towing, there are two forces at play - the lateral force and inertia of the trailer and the vertical load, or 'nose weight'. That is, the effort it takes to accelerate the trailer and decelerate the trailer, and the weight put onto the back of the vehicle.

Does towing damage suspension and tyres?

The answer is no. Trailers have what is known as a 'maximum nose weight', that is the maximum weight transferred onto the tow hitch of the vehicle, and in turn the vehicle's suspension and tyres.

Most trailers and vehicles have a maximum nose weight between 100kg and 150kg. To put that another way, that is no different to carrying a single passenger and some luggage in the boot. So, in the same way carrying a passenger and a big shop or going to the airport doesn't damage your suspension, neither does towing a trailer or a caravan.

However, if you consistently drove with 200kg or more of load in the boot of the vehicle, you would wear the suspension components faster, just as much as if you towed a loaded trailer every time you drove somewhere.

Does towing damage the chassis or brakes?

Again, the answer is no. Tow bars are designed to spread any lateral load through the chassis of the vehicle. In addition, by default the typical owner transitions into an economical and progressive driving style and doesn't drive around like an F1 driver when towing, there is actually less strain put on key vehicle components than if you regularly drive with a heavy right foot.

Most trailers and caravans in the UK use what is known as an over-run braking system. The technology is old-fashioned, but it does work and doesn't require any power. Trailers and caravans over 750kg have a piston inside their tow hitch. As you accelerate or cruise, this piston is extended. As soon as you begin to slow, the inertia of the trailer compresses this piston, which then pulls the brake cables for the brakes on the trailer. A well adjusted trailer actually brakes for the vehicle, and not the other way around, as is commonly misunderstood. 

Does towing create additional wear on the engine?

This does depend largely on how you drive, however towing generally forces most people into a smooth and progressive driving style rather autonomously. Most tow vehicles are diesel powered, and modern turbo charged diesel engines have oodles of torque to handle a trailer.

Whilst you may be towing a 2 tonne caravan, remember that caravan is on wheels and not being dragged along the ground to your destination. The additional load on the car's engine generally isn't any more than a fully loaded car going on a family holiday to a hotel.

Modern turbo diesel engines generally provide more than sufficient torque, such that the vehicle revs barely differ to driving with a largely empty vehicle. We do recommend a minimum of 2 litres and 4 cylinders for trailers and caravans up to around 2 tonnes, and a minimum of 6 cylinders for larger, heavier trailers. This is because the additional cubic capacity of these engine sizes ensures low stress when towing, and the turbos will not need to boost so frequently.

As ever, you should ensure your vehicle is regularly serviced.

Should I buy a vehicle with a tow bar?

The answer is yes. Don't ever discount a vehicle because it has a tow bar fitted. Most vehicles with tow bars fitted were fitted by a previous owner, and the average towing miles of a tow car is less than 1,000 miles per year, which really pales into insignificance when looking at used vehicles. There's a common mis-conception that just because a used vehicle had a tow bar fitted, someone has driven to Tesco, work, Aunt Betty and wherever else every day of their life towing their caravan - it just doesn't happen.

If a vehicle has been used regularly or daily for towing, it will most likely be a large 4x4 or pickup, for which these vehicles are specifically designed for this type of duty.

Considering a tow bar typically costs around £500 to be fitted new, a previous owner has made a sizeable investment into their vehicle, which can even be an indicator that it has been especially well cared for. This also means should you not like the tow bar aesthetically, it has a residual value should you remove and sell it, or can make the vehicle more appealing to any future buyer also.

At Coopers of Hampshire, we can remove tow bar flanges fitted to vehicles for you, on request.

Coopers of Hampshire are an automatic vehicle specialist based just outside Southampton in Ower. All of our vehicles are 115-point inspected and include body condition reports, and unless otherwise stated, include a minimum 3 months warranty. We are a registered company in England, number 14416644. We are VAT registered, number 451375008. We are Accredited by the Motor Ombudsman, the UK’s government-backed, self-regulatory body for the motor industry, registration number 23439.