With the rise of electric and hybrid cars, the need for sustainability in motoring has never been greater. Of course, even fully-electric vehicles still need tyres, so how environmentally conscious are tyres?
Likewise, no matter what car you drive, you eventually need replacement tyres. If you’re environmentally conscious, how you dispose of your old tyres can make a big difference. Here we will explore the various green attributes of tyres, as well as what you can do to help as a driver.
What Are Tyres Made Of?
Of course, a tyre is made up of more than just rubber. We have previously covered the complex nature of tyre construction and it’s many elements but, in short, the tyre ‘carcass’ includes various textile cords and a metal (typically steel) layer.
Still, a large proportion of the car tyre is made of rubber. This includes the tread, carcass and sidewall. On average, estimates suggest these areas take up 85% of the tyre’s rubber, with 35 per cent in both the tread and carcass and 15 per cent in the sidewall. The remaining 15% is used in the liner.
Rubber is the most predominant material used in car tyre construction]
Where Does The Tyre Rubber Come From?
Tyres are one of the largest demands for rubber, making up the majority share of the industry, but where does the rubber itself come from? Traditionally, rubber comes from a Hevea tree
This tree, originally from Brazil, requires a hot, damp environment to thrive, and this is why most natural rubber comes from the likes of Brazil and India, as they have the right climate to grow the tree.
Natural car tyre rubber is created by tapping Hevea trees
However, less than half of rubber used is natural. Many sources use synthetic rubber which use a variety of materials, including crude oil. Natural sap is still used, but the synthetic elements help to provide better parameters, such as heat resistance, which help extend the quality and life of the model.
The rubber car tyre has been used throughout motoring history, as few materials come close to matching its ideal properties. It is firm, but offers enough flexibility to afford it a variety of functions, as well as making it an easier material to work with.
That being said, modern technology is quickly developing new or alternative rubbers to help improve the situation. The Goodyear tyre group, for instance, is experimenting with Guayule, a desert shrub found along many southern U.S states and Mexico. Since the Hevea tree needs the right conditions, often competing with farming, the Guayule rubber represents a way to easily acquire more natural rubber for tyre production.
The Toyota tyre manufacturer, similarly, is using biosynthetic rubbers for various car parts, which utilise more natural components. This is mostly used for drive system hoses, but it could soon extend to tyre production as well. The Bridgestone tyre manufacturer, similarly, is designing airless tyres which use 100% natural materials.
Other companies, of course, are looking to improve the existing tyre rubber and efficiency. Microscopic studs, as seen on the Nokian Hakkapeliitta R2, cuts rolling resistance by as much as 30 per cent. Perhaps more importantly, the microscopic, tiny studs (which are not the same as winter studded tyres) ensures the tyre is still able to perform well, even when worn down.
What Happens To Old Tyres?
Of course, it is possible to repurpose old tyres, by adding new treads. These retreaded tyres have a few benefits and disadvantages which might put some drivers off using them. Despite this, retreading tyres is a great way to use the tyre carcass and the various, undamaged elements of the tyre itself.
There are many ways to recycle car tyres
Another way to recycle tyres is to simply break them down into their various parts. The steel in the carcass, for instance, can be used in a variety of purposes, but there are also many uses for recycled tyre rubber. This involves grinding the rubber down into granules, so that is can be used for a wide range of products, including brake pads, road surfaces and even new car tyres
Likewise, there is always plenty you can do to ensure the lifetime of your tyres. This involves knowing when to replace them, as well as how to store wheels and tyres correctly when not in use, such as when switching between your summer tyres and winter tyres.
As you can see, there are plenty of things to consider with car tyres, and plenty of materials are involved in their construction. Of course, this keeps on changing, as manufacturers are looking to make the best performing tyres possible.