Adrian Newey has revealed that Audi was the driving force behind the aborted plans for Formula One to switch to four-cylinder engines in 2013.

Last December the FIA's World Motor Sport Council agreed on the switch to four cylinders, only for the F1 Commission to change its mind last week and propose V6s be brought in for 2014 instead. Newey said Audi's wavering commitment had contributed to the switch from four-cylinders to six, after the German car giant made a u-turn on a pledge to join the sport if it switched to four pots.

"The initial decision from the engine working group was for a four-cylinder turbo to be introduced for 2013," said Newey. "The big driver behind that was Audi. They said they would come into the sport if there was a four-cylinder turbo, and that's what everyone agreed in order to get Audi in. They subsequently decided that they won't bother after all, thank you very much, and we were lumbered with a four-cylinder turbo."

He said a V6 turbo is a much more practical solution due to its dimensions.

"You can then get into the politics of the whole thing," Newey added. "Certainly from an engineering point of view a four-cylinder turbo is not a nice engine to install, you've basically got to put a spaceframe around it, you can't make it a properly structural. A racing V6 is a much nicer engine to package. That will now be the 2014 engine."

Under the original four-cylinder the engines were only going to be allowed to rev to 12,000 rpm, but Newey said that might be increased amid concerns that the engines will sound too muted.

"The revs are still being debated, but it looks as if it will probably be around 14,000 or 16,000," he said.

The FIA has announced that the new 1.6L V6 turbo engines will have a rev limit of 15,000rpm and will still ensure Formula One has a unique sound.

There has been speculation of what the limit would be as Bernie Ecclestone and the circuit owners had voiced their concerns at the sound of the new engines. After Adrian Newey told BBC Sport in Valencia that he expected the limit to be "around 14,000 or 16,000", the FIA announced in a Q&A press release that the limit had been agreed on a middle ground.

"This parameter has been updated from 12000rpm to 15000 rpm to allow engineers more flexibility in power and energy management," the FIA release read. "However, as a consequence of the new architecture (V6) and the change in rev-limit, the engine will sound different, but will remain representative of Formula One."

The clarifications come after the FIA ratified the new power units for 2014 on Wednesday. In a further challenge to the engineers, the FIA announced that the fuel flow had not changed from the initial limit imposed in order to force the engines to be even more efficient.

"The fuel flow limit will stay the same. The technologies are the same and as a consequence any increase in rpm will constrain the engineers to work harder on reducing friction and gaining on engine efficiency. The challenge will be even bigger than originally planned and will therefore enhance the technological lead of Formula One."