Factory Yamaha MotoGP riders Ben Spies and Jorge Lorenzo were encouraged to finish the opening night of the Qatar night test much closer to the pace-setting Hondas than they had been at Sepang.
Although RCV riders Dani Pedrosa, Casey Stoner and Hiroshi Aoyama locked out the top three places on Sunday evening, Spies was just 0.292secs from the front in fourth.
"We made the bike go in a pretty good direction today and hopefully we can get a little bit more out of it,” said the Texan. “We want to try another tyre tomorrow that we haven't used yet, all in all it's been a good first session.
“The bike seems to be closer to the front than Malaysia and I've got pretty good expectations after the first day. The track is a lot more flowing here which suits our bike well; I think this should be a good track for us."
Reigning world champion Lorenzo, who set more sub-1min 57sec laps than any other rider on Sunday, agreed with his team-mate.
"It seems we are closer to the Honda guys than in Sepang so I'm happy," said Lorenzo, who was fifth fastest and 0.411sec from Pedrosa. "We are going to continue and try a few different things tomorrow to try and find some more grip as well.
"We tried a few different things on some corners today to try to make the bike more stable when I open the throttle; in almost all the gears we have done a good job."
"As we suspected when the temperatures are a bit colder we get a benefit,” added team manager Wilco Zeelenberg. “We confirmed everything we needed to test so everything is under control so far."
Monday will mark the tenth and final day of 2010/2011 winter testing, with opening practice for the Qatar Grand Prix taking place on Thursday.
An injured Lorenzo finished a close second to team-mate Valentino Ross in last year's Qatar race, while Spies was fifth for Tech 3 Yamaha in his first race as a full-time MotoGP rider.