NASCAR president Mike Helton told The Associated Press that the rule is expected to reduce team costs tied to engine research and development.
``It's not going to have a huge initial impact,'' he said. ``But it's part of the ongoing effort to minimize corner speeds by controlling tires, aerodynamics and engines.''
The new rule will be in place at tracks in all three national series with the exception of Daytona International Speedway and Talladega Superspeedway, where NASCAR already limits horsepower with carburetor restrictor plates.
In a related announcement, NASCAR confirmed it will reduce rear spoilers in the Cup series by an inch, to 4 1/2 inches, at all non-restrictor plate tracks next season. NASCAR decreased the spoilers by three-quarters of an inch entering the 2004 season in another effort to promote more passing.
NASCAR chairman Brian France said the sanctioning organization talked extensively with team owners before deciding on the gear rule.
``Rpms have been on a continual rise since the 1970s and the associated costs of gaining an edge in that area have escalated substantially during that time as well,'' France said. ``We have also noticed a substantial decrease in the number of engine builders over the past several seasons and this new rule should help reverse that trend.''
Engine builder Ernie Elliott said several weeks ago in an interview with the AP that he didn't think the new rule would accomplish what NASCAR hopes.
``NASCAR seems to think this is going to bring the have-nots closer to the haves,'' Elliott said. ``But the truth is the haves will just find a way to make up for the lost rpms by spending their money somewhere else.''
The rule will force teams to rebuild their inventory of engines, a huge upfront cost. But once the rpms are cut back and NASCAR has placed a cap on how high they can go, teams will save money because they no longer will constantly test new developments.
Most teams are getting about 9,500 rpms and producing about 800 horsepower, but NASCAR will cut both those numbers under the new rule.
``To limit rpms and engine costs in the future, they have to start somewhere,'' car owner Ray Evernham said. ``I mean where is the rpm going to go? 12,000? Like any rule, initially it will probably cost a little more money, but I think it can work.''
AP contributed to this article