The economic downturn is having an impact on drivers that goes beyond the cost of petrol, it has been claimed, with drivers delaying essential replacement of their tyres.According to Protyre, evidence exists that drivers are taking the risk of driving on worn and possibly defective tyres.It claims drivers are putting themselves and other road users at risk, as old tyres could potentially cause an accident and costly car insurance claims, as well as resulting in a prosecution.Adrian Walsh, director of RoadSafe, described the company's research as "worrying"."Clearly drivers are delaying the replacement of worn tyres which is a false economy and will place drivers at greater risk of having an accident."The Highway Code states that tyres must be inflated to their manufacturers recommended level and have a tread depth of at least 1.6mm around the entire circumference of the tyre and three-quarters of the breadth of the tread.