The tyre re-treading service in Ho Chi Minh City has for long helped vehicle owners in Ho Chi Minh City achieve significant savings by not having to buy new tyres and still passing quality examinations.
However as the service increases in popularity and more people take advantage of it, experts are raising safety concerns.
A car tyre retailer in District 12, identified only as Phuoc, keeps old tyres in his store's backyard. Customers can choose the ones they want and have it renewed.
There are hundreds of tyres in different sizes of Bridgestone, Michelin and Yokohama brands in the backyard.
Phuoc said when be buys the old tyres at VND200,000-500,000 (US$24) each, they only have around 30 percent of the quality of a new one.
Since the business is highly competitive with hundreds providing the retreading service, he has to book the old tyres in advance with vehicle owners and send his workers to get them, sometimes to locations outside the city.
Once the tyres are bought, a group of workers begin to make new treads for the tyres which are then painted black all over to make them look new and to hide signs of retreading.
It takes around 50 minutes for an old tyre to look all new again.
A truck owner named Hung said his tyres are worn every few months, so he chooses the cheap retreaded ones to save money.
A retreaded tyre costs VND700,000-1.5 million ($72), compared to new ones at VND2-8 million. If a customer brings their own old tyre, the retreading work costs VND40,000-50,000 ($2.42) each. So the retreading enterprises make a handsome profit.
However, there could be more than the apparent win-win situation for everyone concerned, experts say.
Nguyen Huu Huong, senior lecturer of transport technology at Ho Chi Minh City University of Polytechnics, said people should not use retreaded tyres.
Huong said to retread a tyre, which was already worn, would damage its rubber fiber.
"That would cause traffic accidents, very dangerous when the tyres are driving on highway."