The struggling Swiss-based Formula One team are last in the standings and still without a point after 16 of the season's record 21 races.
Including last year's results, they have not scored for 19 races in a row.
"We will be using the latest specification of the 2016 Ferrari engine in 2017," Kaltenborn told reporters at Suzuka. "We took this decision a while ago...at a time where actually the rules for next year were not 100 percent clear.
"We took a strategic decision that we want to focus the resources we have on chassis development and performance development, and in a way leave the engine side to the areas we know," she added.
The decision means only Ferrari and U.S.-owned Haas will have the latest engines next year with Red Bull-owned Toro Rosso, who currently use 2015 specification units, switching to Renault.
Kaltenborn said the team was financially stable and the 2017 car's development remained on course.
Sauber, Formula One's fourth oldest team, announced in July a change of ownership with Swiss-based investment firm Longbow Finance taking over. The current drivers are Sweden's Marcus Ericsson and Brazilian Felipe Nasr.
(Reporting by Alan Baldwin, editing by Toby Davis)
