All-new turbo V6 rules are currently scheduled to debut in 2014, but Germany's Auto Motor und Sport and Italy's Autosprint say some of the midfield teams are opposed on cost grounds.
"It is being heard from sources at (engine suppliers) Mercedes, Ferrari and Renault that the development of the turbo V6 is more expensive than expected," said the German report.
"Since no limit for the engine renting costs from 2014 has been set, the (small) teams fear that they will incur additional costs."
Currently, each non-works team pays about EUR 8 million for 16 normally-aspirated V8 engines and a few test engines, and up to 5m for KERS.
Another factor is the speed of the F1 cars, which is already beginning to be rivaled by the junior GP2 category. The new V6 turbo engines will be about 25kg heavier.
Italy's Autosprint speculated that the dispute could mean the V8s stick around in F1 for "one or two more seasons".