Leon Haslam believes his Suzuki Alstare can be a match for the twin-cylinder machines on race day, but only if the Valencia circuit continues to give up good grip.

The World Superbike Championship leader will start fourth on the grid in Spain as he looks to increase his advantage in the standings over his rivals, including closest rival Max Biaggi who starts just alongside in third.

However, Haslam says work still needs to be done before the races before he is fully satisfied with his machine, adding that the set-up is sensitive to temperature changes.

"I'm pretty happy how today went, though there's still work to do," he said. "The biggest problem for us at the moment is the temperature, because that is affecting how the bike works. Generally, I'm happy with the bike on race rubber and I'm also happy with the balance and set-up of the bike.

"Normally twins go well here, but when the four cylinder bikes have good grip, then they are a match for the twins and that's what we've seen today. We'll make a few minor tweaks to the bike in the warm-up tomorrow morning and see if we can improve the bike further.

"I'm feeling pretty confident that we're going to get some good results tomorrow and hopefully leave here still leading the championship."