Detroit's automakers are getting some help from the federal government, at least in terms of their efforts to find flaws in the new Toyota Tundra pickup, a newspaper reported.

The New York Times (NYT) said the new full-size Tundra, built in a new plant in San Antonio, Texas, got a four-star head-on crash rating from the federal National Highway Traffic Safety Administration (NHTSA), rather than a perfect five stars. Competitors were expected to take advantage of the news.

The NHTSA has given perfect scores to all full-size pickups made by Detroit-based automakers such as Ford's F-series, GM's Chevy Silverado and Chrysler's Dodge Ram.

Given Toyota's reputation for building safe cars, the Tundra's four-star rating is viewed by many as an embarrassment for the automaker, which has acknowledged the Tundra to be the most important vehicle it has ever sold in the United States, the NYT said.

The paper said five stars indicate that the chances of suffering serious injuries are less than 10%, while four stars mean the chances are 11% to 20%.

The newspaper noted that the government has proposed changes to its crash-test rating system because it says too many vehicles receive five stars.

Toyota spokesman Bill Kwong told the New York Times the automaker "would have loved to see five" but noted that its own testing found that the Tundra meets or exceeds all crash-protection standards.

"If somebody's tests show that our vehicle is not quite there, we need to go back to the drawing board and find out why," Kwong reportedly said. "I'll bet our engineering team is crawling all over this thing as we speak and trying to find out what went on."

The NYT said Detroit's automakers began trying to pick apart the Tundra long before it went on sale in February. Recently a GM sales manager sent an e-mail message to dealers disputing claims Toyota makes in its ads for the truck.

A Ford spokesman, Jim Cain, suggested to the paper that the Tundra's rating could be incorporated into Ford's advertising campaign, which compares the abilities of vehicles like its own F-series pickup with those of competing products.

"Why wouldn't we?" Cain asked the New York Times. "They can't beat us on capability and now they can't match us on safety."