WASHINGTON (AP) _ Ashland Inc. has agreed to stop advertisements for a Valvoline automotive additive that the government charged were unsubstantiated, the Federal Trade Commission said Wednesday.

Ashland, based in Russell, Ky., had claimed its Teflon-containing Valvoline TM8 Engine Treatment reduced engine wear by up to 75 percent, provided twice as much wear protection under high temperature conditions, extended engine life and improved fuel economy.

In its complaint, the FTC said that the company did not have a reasonable basis for the claims and that tests failed to substantiate them.

The consent agreement prohibits Ashland from making any claims about the performance or attributes of any engine treatment unless it has evidence to support them. It also bars misrepresentations of any tests or studies.

The agreement was the latest in a series of FTC cases involving unsubstantiated or false claims for automotive additives and high-octane fuels.