The sport utility vehicle, or SUV, and its spin-off class known as the crossover or CUV, are now the most popular types of vehicles. In the United Kingdom, they account for more than half of all new cars sold, and the story is similar the world over.
Yet SUVs are controversial and have recently been targeted by a sustained campaign by activists who have deflated their tires (spelled ‘tyres’ in the U.K.) overnight, citing their carbon emissions, air pollution and danger to pedestrians. The group, called Tyre Extinguishers, said: “We want to make it impossible to own a huge polluting 4x4 in the world’s urban areas.”
So, while people keep buying these vehicles, are they really making the best choice for the environment or safety? Let’s look at the evidence.
To truly understand SUVs, though, we first have to look at the reasons why these vehicles are so popular and how they came about. Most agree that the first true mass-produced four-wheel drive was the Willy’s Jeep – a vehicle created to transport U.S. soldiers over rough ground in the Second World War. Britain’s answer to the Jeep was the Land Rover, which followed a similar design ethos but became slightly more livable and more appropriate for everyday use, with proper doors and better weather proofing.
The Range Rover, a vehicle that was introduced in 1970 and remains popular today, was perhaps the true original SUV. It combined the features of a luxury saloon car with the ability to effectively drive on rough terrain off-road. The Range Rover spawned hundreds of vehicles in a similar style, and it wasn’t long before every manufacturer was making SUVs, even those known for sports cars, such as Porsche and Lamborghini.
Within the same approximate footprint as a regular car, SUVs offer more space for passengers and luggage – useful since evolution means humans are getting larger. The flip side of this is that all cars – even minis – are getting bigger, too, so you wouldn’t necessarily need an SUV if you want more space.
Many drivers also report that they like the higher driving position and off-road ability. That said, many crossover vehicles do not have four-wheel drive, so they are no better than any other car in this respect.
We urgently need to reduce the greenhouse emissions from road transport. The good news is that key markets like Europe are actually doing well in setting targets to reduce tailpipe emissions, and in many cases, hitting them early. However, SUVs could start to reverse this trend.
- More material: Since SUVs are larger, they use more materials in their production than the car they are based on. A Volkswagen Golf, for instance, weighs around 1,330 kilograms, while the Tiguan, a Golf-based SUV, is 1,534. That extra 200 kilograms of metal, plastic and rubber – the weight of several people – all use additional raw materials and more energy to be produced.
- Worse fuel economy: The extra weight also means they don’t achieve the same fuel economy as a normal car, because the engine has to work harder to get the car moving. SUVs also tend to be further off the ground (a higher “ride height”). That makes them less aerodynamic and means worse fuel economy when travelling at speed.
- Risk of rolling: The fact the mass of the vehicle is higher off the ground also gives SUVs a higher centre of gravity, which increases the risk of a roll-over in an accident. A study in the U.S. showed that SUVs have an 11 times higher risk of rolling over in an accident and children in vehicles that roll-over have a two times higher risk of dying in that accident.
- Pedestrians in peril: Back to the weight. Many owners may assume that the larger SUV is safer, yet the U.S. National Highway Traffic Safety Administration observed that decreasing the weight of SUVs would reduce the seriousness of accidents by between 0.3 and 1.3 per cent. This is a more difficult thing to quantify than the effect on fuel economy, and conversely crash safety equipment usually adds weight too, but drivers should not assume an SUV is safer by virtue of its increased weight.
Blind spots and high bonnets make SUVs particularly dangerous for pedestrians. Indeed, a recent study in the journal “Economics of Transportation” concluded that replacing the U.S.’s growth in SUVs with regular cars over the past two decades, “would have averted 1,100 pedestrian deaths.” The author also found “no evidence that the shift towards larger vehicles improved aggregate motorist safety.” Another smaller study in the U.S. in 2020 showed that SUVs cause more serious injuries and deaths when they strike pedestrians, especially over 20 miles per hour (32 kilometres per hour).
Tom Stacey is a senior lecturer in operations and supply chain management at Anglia Ruskin University in East Anglia, U.K. This column was originally published by The Conversation.