AutoExpress wrote:

Research conducted by German motoring watch-dog DEKRA found that aiming the spray directly at the sidewall can cause tiny, barely detectable holes to appear on the rubber. And according to experts at the UK's leading tyre safety organisation, TyreSafe, with the sidewall weakened, the chance of a blow-out is hugely increased.

The group also warned against using strong detergents. When combined with a high-pressure blast of water, they can remove important protective chemicals from the compound. This damage, which could show up as a brown watermark, reduces both durability and grip.

With more than 80 per cent of drivers apparently unaware of the perils, TyreSafe has issued some potentially life-saving guidelines. Avoiding machines which run at pressures of more than 110 bar is top of the list, but the body also recom­mends using the widest spray pattern.

In addition, it advises owners to keep the washer nozzle at least 20cm from the surface of the tyre when cleaning, and not to aim the jet directly at the join between the tyre and rim.