Hulkenberg has not scored points since the opening round of the season in Australia, while team mate Sergio Perez has made the top ten just twice - leaving Force India seventh in the constructors' championship, two spots down on their finishing position last year.
Asked by Formula1.com to pinpoint the reasons for that downturn, Hulkenberg said: "Two things are responsible for not being as competitive and quick as we thought.
"Firstly, my guess is that we've been a bit out-developed over the winter. And secondly, luck hasn't kissed us in races like China, Bahrain and Russia. A few unlucky incidents - the timing being not quite right - and that's what you get."
As to whether he expects an upturn from the updates Force India brought to Barcelona, and are continuing to evaluate in this week's in-season test, Hulkenberg added: "Of course we have a lot of hopes and expectations pinned to this package.
"It will take time to fully understand what we've got here - and what from the new parts and pieces will be implemented in the long run. I think at the next couple of races we will get wiser.
"We have already found more performance in the car in the wind tunnel, which we will introduce later in the year. So there is no standstill. The season is still young and you cannot let it stand as it is right now.
"To be honest right now the standing in the constructors' championship is not really on my agenda. All we are working on now is to bring performance back to the car - and start scoring points again. We will see where that takes us. We have 16 races to go - that is a marathon!"
Neither Hulkenberg nor Perez is testing in Spain this week, with driving duties instead being handled by Force India's development driver Alfonso Celis.
