- Spanish Grand Prix
Barcelona to be DRS's biggest test yet - drivers
The DRS has divided opinion in the paddock since its introduction at the start of the season but, combined with the new Pirelli tyres, has improved the chances of overtaking dramatically. It works by allowing drivers who are within a second of the car in front and on an FIA-prescribed part of the circuit to adjust their rear wing and boost their top speed.
At the last three races the system has worked well - possibly too well in Turkey - but Barcelona has seen very little overtaking in recent years and Hamilton is not sure whether that will change this time around.
"It will be interesting to see how the DRS affects the racing," he said. "Typically, it's been very tough to overtake at Barcelona because the best opportunity - into the first corner - is too fast to make a pass stick. It's always been too hard to really get alongside another driver into the corner.
"But we benefited from two great races in China and Turkey because the DRS area led directly into a heavy braking zone, meaning it was possible to get two bites of the cherry: using the slipstream and using the braking zone. In Barcelona, it's likely to be less clear-cut."
Lotus driver Trulli said the DRS could transform the circuit if it has the desired effect: "There's not a lot of overtaking chances around the lap and we'll see if the DRS plays the same role in Spain that it did in Turkey - if it does then tracks like Barcelona will suddenly have overtaking chances and that's got to be good for the fans."
Mercedes' Schumacher added: "We know the Circuit de Catalunya very well from testing, but it will be interesting to see the effect of KERS, the DRS and the Pirelli tyres on a track where overtaking is always difficult."
Kamui Kobayashi, who drove his Sauber from the back of the grid to 10th in Turkey, is more optimistic.
"In the past overtaking was particularly difficult on that circuit, but I believe the Drag Reduction System will help to make it an exciting grand prix," he said. "I feel very much at home using the adjustable rear wing. I'm happy with the system and I think it will be a real benefit for the Spanish Grand Prix's audience."