Peter Sauber says it "doesn't look" as if any of the teams have found that "revolutionary invention" that puts their car in front of the chasing pack.
In recent years, the F1 teams have found innovations that have given them the edge over their rivals, starting with Brawn GP's title-winning double diffuser.
The following season it was the F-duct while last year Red Bull Racing put their blown diffuser exhaust to great use as they stormed to the Championship double.
As the double-decker diffuser and F-ducts were banned, so too has the blown diffuser exhaust as the FIA look to close all loopholes.
F1 technical departments, though, have some of the brightest minds in motorsport, although this season Sauber reckons they have failed to find that innovation.
"The big question is of course whether anyone, after the banning of the adventurous engine control (off-throttle-blowing), had found another revolutionary invention similiar to the blown diffuser," the team boss told Swiss newspaper Blick.
"So far it doesn't look like it.
"At the rear of the individual cars there are different solutions for the guiding of the exhaust gases but this is nothing unexpected."
Sauber also ruled out the suggestion that times set during last week's four-day test at Jerez are an indication of what is to come this season, saying everyone will have to wait until the very last day of running at the final test in Barcelona to get even a glimpse of the pecking order.
"Of course it is clear that our opponents do not stand on the spot. All will work until the very first race at full speed.
"Therefore the lap times are nothing more than a snapshot. We also do not know what fuel loads our rivals are using.
"Any attempt to create a ranked list based on Jerez is for me no more and no less than reading tea leaves.
"Only at the last test, when the teams try the updates for Melbourne, will the fog of uncertainty clear."
