Formula One announced a deal with the sport's four engine manufacturers on Friday to reduce prices over three years from 2017, ensure all teams are supplied and reduce performance gaps.
The governing International Automobile Federation (FIA) said in a statement that the agreement had been approved by its World Motor Sport Council and would now be written into the regulations.
As part of the agreement, thrashed out over months, the FIA committed to stable power unit regulations until 2020 -- something the manufacturers needed to make the engines more affordable.
Research into "improving the sound", which means cranking up the volume to appease fans yearning for the old ear-splitting V8 wail, was under way with the aim of implementation by 2018 at the latest.
The 1.6-litre V6 turbo hybrid power units, made up of six main parts including the internal combustion engine and energy recovery systems, were introduced in 2014.
While far more fuel efficient, and technologically relevant to road car production, than ageing V8 engines, the new units have also been considerably more expensive.
A customer supply can cost well in excess of 20 million euros ($22.89 million), depending on the manufacturer, whereas FIA president Jean Todt has said 12 million would be an acceptable amount.
The FIA had threatened to introduce an independent power unit supplier if a deal could not be reached.
It said the new agreement would reduce the cost by one million euros in 2017 compared to 2016 prices. From 2018, the price would drop by a further three million euros.
"Cost reduction on power units will be driven by changes to the sporting and technical regulations in 2017 and 2018, with a progressive reduction of the number of power unit elements per driver per season," the FIA said.
Drivers are currently allowed five units per season, with penalties applied if they exceed their allocation.
The FIA said there would be an obligation to supply all teams, a bone of contention last year when Mercedes, Ferrari and Honda all ruled out providing engines to rivals Red Bull after that team fell out with Renault.
Red Bull are now using Renault units with Tag Heuer branding.
Measures to reduce the performance gap, with Mercedes dominant since 2014 and newest arrivals Honda still some way off the pace, would include the removal of a system of 'tokens' limiting development during the season.