In Spain the fastest Lotus was 3.5s off the pace of the fastest Sauber, 4s slower than the fastest Toro Rosso and 0.2s quicker than the fastest Virgin. In Monaco the fastest Lotus was 0.3s quicker than the fastest Sauber, 2.1s slower than the fastest Toro Rosso and 2.3s quicker than he fastest Virgin. The nature of the circuits may have played a role in that, but there's no doubt that Lotus have made progress and Heikki has a point about challenging the Saubers, but whether the team can maintain that is another question.