Toyota may have emerged as Brawn GP's closest challenger so far this season, with podium finishes in the first two races, but the team has not yet done enough to totally appease its Japanese bosses.
That is the view of Toyota team president John Howett, who says that despite the outfit's strong showing, senior board members in Japan will not ease off their pressure until the team has won its maiden race.
Speaking to AUTOSPORT as to whether or not Toyota executives are now at ease with what the F1 team is doing, Howett said: "I think they are very positive, but they are still urging us to make that final step. They won't rest until we get there. But we won't either."
Toyota has benefited in the early part of the season from being one of just three teams that has used the double-decker diffuser.
With rival teams now developing the concept, following the FIA's final approval of it earlier this week, Howett is expecting tougher competition for the rest of the year.
"We want to win, but we've got to look behind us because I am sure some of the others will catch us," he said. "We have a couple of tenths to find to the Brawn cars, so it is still a very intense season.
"The Red Bull has been intensely competitive, there is not that big a gap to them, and they don't use it [the double-decker diffuser]. That is why there are a lot more areas of opportunity to develop performance, and I know there are some very professional teams there.
"We cannot sleep for one minute. I expect that it will still be a very difficult fight with other teams emerging mid season with very, very quick cars. And I am sure that some of the people who are dissatisfied or unhappy at the moment will be very competitive later in the season."