Alarmed by dozens of reports of deadly rollovers of Yamaha Rhino off-road vehicles, the Consumer Product Safety Commission took action early last year. The agency pressured Yamaha to announce a “free repair program” — a recall by another name — to make fixes aimed at improving the vehicles’ stability.

The move by the agency, after eight years of lethargy under the Bush Administration, was widely viewed as a sign of its revival as a vigorous safety regulator.

Nearly 19 months later, however, the commission is refusing to disclose whether its actions in the Rhino case had the intended effect. It has turned down a request under the Freedom of Information Act to reveal how many Rhino owners have taken advantage of the free repairs.

In a letter denying FairWarning’s Freedom of Information request, the commission said it was withholding the data under a duty to protect “trade secrets and confidential commercial information…whose disclosure could give a substantial commercial advantage to a competitor.”

Why the number of Rhino owners getting the repairs might be a trade secret was not explained. A Yamaha spokesman would not discuss the matter. At the safety commission, spokesman Scott Wolfson said the Rhino case is still open, and “there are elements of the case that may not be disclosed at a given time.”

Yamaha submits periodic reports to the commission on the number of Rhinos brought for retrofitting. By law, before releasing data submitted by companies, the agency must notify them and weigh any confidentiality claims they raise. However, the companies can’t veto the disclosure, and the agency must decide if their claims are valid.

“It’s hard to believe that the intent of the Freedom of Information law has been fulfilled in this case,” remarked Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists. “Does Yamaha have a legitimate interest in protecting the information,” he asked, “or are they simply trying to stifle a story that does not reflect well on them?”

Moreover, he said, if the data show that relatively few Rhino owners responded, it would indicate that the action “did not achieve its intended result.”

Dropping the term “recall” was a concession by the agency to get Yamaha to act. At the time, however, agency officials expressed concern that failing to describe the action as a recall — a term that resonates with consumers and news organizations — might result in a weak response.

Manufacturers would rather use another name, but “from the consumer advocacy perspective, I’d rather things be called a recall because consumers know that term,” said Rachel Weintraub, senior counsel for the Consumer Federation of America.

Yamaha’s steadfast insistence that the Rhino is perfectly safe might also lead owners to dismiss the need for the repairs. The stance is crucial to the company’s defense of at least 700 lawsuits, most stemming from serious injuries and deaths when Rhinos tipped over, crushing riders’ feet, limbs or heads under the 1,100-pound machines.

Yamaha has claimed the Rhino is well-designed, with an array of safety features including seatbelts and and a roll cage. The company has blamed accidents on operators engaging in risky stunts or failing to heed warnings, such as the need to wear a helmet and to limit operation to drivers at least 16 years old.

As FairWarning reported last month, Yamaha has won four of five Rhino cases that have been tried to jury verdicts. It has quietly settled at least 40 other cases. Bolstering the plaintiffs’ claims is the commission’s finding that many rollovers appeared to involve turns at relatively low speeds on level ground.

Wolfson of the safety commission said that from the perspective of its chairman Inez Tenenbaum, the March, 2009, Yamaha announcement “was a recall.” Moreover, Wolfson said, “We do continue to urge all owners of the Rhino who have not taken advantage of the repair program to do so immediately.”

The free repairs include putting spacers on the rear axle to widen the Rhino’s stance, and installing doors on vehicles that do not already have them. In addition, Yamaha has offered a $100 coupon towards purchase of a helmet for owners who watch a safety video.

Introduced in late 2003, the Rhino was a trail-blazer in more ways than one, creating a new category of off-road machines known as ROVs (recreational off-highway vehicles) or side-by-sides — because unlike all-terrain vehicles they have seats for two. Rhino sales have topped 150,000, and several rival models have also achieved high sales.

The safety commission is conducting handling tests of the Rhino and other leading models as part of an effort to draft federal regulations for ROVs. Through July of this year, the commission said it had received reports of 152 deaths in ROV crashes — 70 involving the Rhino and 82 with other models.