The E21's tyre management was key to Kimi Raikkonen's Australian Grand Prix victory as it allowed him to make only two pit-stops compared to the three of his main rivals.
While Lotus is confident that the car is one of the best in terms of tyre degradation, technical director James Allison doesn't count on being able to do this everywhere.
"It's fairly finely-balanced and we can't assume that we will be able to pull off the trick of running one fewer stop than everyone else at a competitive pace everywhere we go," Allison told AUTOSPORT.
"The car is good, the drivers have both said that from the outset and they have a good feeling about it, but it's not a given at all.
"It doesn't take much to shove the tyres from being able to do the two-stopper that Kimi managed to the three-stopper that Romain [Grosjean] ran."
Allison admitted that the car's qualifying performance was roughly representative of its position in the competitive order, but that the tyre characteristics this year means that starting position is not as important as it was at the end of 2012.
Raikkonen and team-mate Grosjean locked out the fourth row behind the Red Bull, Ferrari and Mercedes cars.
Lotus has downplayed expectations of a title bid, but Allison is confident that the car can continue to be in the mix as long as the tyres remain key to race form.
"On one-lap running, we are the third or fourth quickest team and that means we are going to be somewhere from fifth to eighth [in qualifying]," said Allison.
"The indications from the car are that it is capable over a wide range of tracks of running competitive in the races.
"The tyres are less of a story than everyone was anticipating but they are more highly-strung than last year.
"Qualifying pace is therefore slightly less important than it was at the tail-end of last season because it doesn't take many laps at 0.2-0.3 seconds a lap degradation before the qualifying pace is meaningless."