Automakers and car dealers, who in radio ads could refer consumers to an 800-number or to newspaper ads, now will have the same ability in TV commercials.
Ad and auto industry groups said the rules unveiled last week could have the effect of increasing TV advertising for car leasing.
The Federal Reserve toughened some other parts of the rules, in ways that could change the way lease prices can be advertised.
Effective Oct. 1, 1997, advertisers who claim $0 down and $250 a month in large type, for example, can no longer put "acquisition costs" or other charges in small type below that. The rules require all three numbers to be of equal type size.
The Fed also said that advertisers who list any interest rate in their ads have to put right next to it, and not in small type far below, a statement that the cost may not reflect all charges.