The FIA World Motor Sport Council has ratified the World Rally Championship's switch to non-turbocharged Super 2000 cars from 2011.
While it had been known for some time that the S2000 rules would form the basis of the WRC's next technical package, there was continued debate over how much the more standard cars would be modified for rallying's premier category.
The FIA Rallies Commission decided last month that turbochargers should not be added, and that the only change to the basic S2000 rules would be the addition of extra aerodynamic components. That suggestion was officially approved at today's WMSC meeting.
Both S2000 machines and the current World Rally Cars will be eligible for the WRC next season, before S2000 takes precedence for 2011 and 2012.
The WMSC also agreed with the Rallies Commission's proposal to move to 1600cc turbocharged cars from 2013 onwards.
"From 2013, it is proposed that the World Rally Car will continue to be Super 2000 based with a cost-effective 1.6 litre turbo engine,"
said an FIA statement.
"This is subject to review, based on the specification of the car produced by manufacturers for the mass market."
S2000 cars currently compete in the Production class of the WRC, with Patrik Sandell winning the division in a Skoda Fabia in the last two rounds, and are the top category in the rival Intercontinental Rally Challenge, which has attracted works-backed S2000 entries from Skoda, Abarth, Peugeot and Proton.
WRC champion Sebastien Loeb has previously hinted that he would quit the series if S2000 cars were adopted without significant modifications.