I have read that Formula 1 cars use another brand of filters made of cotton. Does this mean they are better than Pipercross filters?
Not really. Formula 1 competition filters use a wide mesh that lets through a very large quantity of air and traps only the larger impurity particles which could damage the injectors or pistons during the race. Finer dusts are not filtered, since these engines are taken apart completely and serviced after each race. The “used in Formula 1” claim does not translate into benefits for regular road or sport use. Here it is important to ensure that the air supply is always in peak conditions. If you require very clean air together with performance airflow the right choice is Pipercross.