Bridgestone urged to improve markings

The two different tyre compounds used each weekend now have to be 'visibly' distinguishable following a last-minute rule change by the FIA, as exclusively revealed by autosport.com.

However, Bridgestone's introduction of a small white circle at last weekend's Australian Grand Prix was generally deemed to be a failure as observers could not see the marking once the car was moving - even at slow speed.

And although Bridgestone have said that major changes are unlikely to be made until the Spanish Grand Prix, leading figures within the sport have called for something to be done before then.

BMW motorsport director Mario Theissen said: "I think it could be good if every spectator understands what goes on. And if the spectators don't understand it, then we should not do it.

"We need to make it clear what type of tyres people are running. The current idea is not a solution because they (the circles) are difficult to see when the car is still, and as soon as the car is moving there is no chance."

Williams technical director Sam Michael told autosport.com: "I have to acknowledge that it is pretty hard to see the tyre. We can see it because we know exactly what we are looking for and where to look for it, but from a spectators point of view you would not be able to see it.

"Maybe a better solution would be to paint the bottom of the grooves. The grooves don't wear, so you would see a white stripe from the front view.

"You could maybe paint one groove, maybe the outside one, on all the tyres - although that is quite a bit of work for Bridgestone."