Morale at the Detroit Three auto makers is on the upswing, reports, a website that lets workers anonymously critique their employer in exchange for anonymous salary information.

According to the study, dubbed, “U.S. Auto Manufacturer Company and CEO Report Card,” Ford Motor Co. employees are more positive about the direction of their company than counterparts at General Motors Co. and Chrysler Group LLC.

Workers participating in the online review process gave Ford a 3.6 rating, which falls into the “satisfied” category.

Chrysler and GM employees rated their workplaces 3.1 and 2.9, respectively, qualifying for an “OK” grade.

Last year, Ford and GM both earned a 3.0, while Chrysler garnered a 2.7, the study reveals.

While GM is down slightly from 2009, the rating doesn’t reveal the entire picture, says Tim Besse, Glassdoor’s co-founder and vice president-marketing.

“GM’s had four CEOs (in the past 17 months), so it’s a revolving door there,” he tells Ward’s, noting that sort of upheaval normally would result in a greater drop.

While not overwhelmingly positive, the Detroit Three ratings come as a surprise to Besse, given the amount of uncertainty surrounding the industry.

“Despite the turmoil and changing leadership structures, they’ve actually improved from an employee-satisfaction perspective,” he says. The website promotes honest evaluations, with staffers reviewing each entry, Besse says. Those posted by employees looking to “vent” are discarded. Any postings containing possible company secrets also are deleted.

Each review must list both pros and cons of the company to provide a balanced evaluation. Glassdoor rewards those who post a review by allowing them full access to the site’s information on companies and the salaries they pay.

When the site launched in June 2008, it had data on only 250 companies and included just 3,000 reviews. Today, it covers 90,000 companies and features 1 million reviews, Besse says.

In one posting, a Ford marketing manager says it’s a “good time to be with Ford,” but offers some constructive criticism. “Corporate processes are still a bit clunky and needing further streamlining.”

A GM manufacturing engineer says, “The best part of GM is the flexibility. Being a large company, you have people that can cover for you if you need time off. The pay is competitive and (includes) a great benefits package with time off.

“(But) it is difficult to advance without getting someone to like you. The company also doesn't have a program for career growth. It feels constricted that you don’t (know) how to advance either.”

A Chrysler engineering manager says the company has a “bright future,” but warns it has “very thin resources and new management approach is company-first, dedication with no regard to work/life balance if you want to move ahead.”

Although most postings offer mixed opinions about daily life, views on top leadership are decidedly positive.

According to the study, Ford CEO Alan Mulally is the top-rated Big Three executive, with an approval rating of 96% between mid-August 2009 and mid-August 2010. That’s up from 86% in the year-prior time frame.

“Ford is a standout,” Besse says. “Mulally is one of the top-rated CEOs on the site, up there with (Apple Inc. CEO) Steve Jobs.”

Despite the “revolving door” at GM, its past CEOs have proven popular with the rank-and-file.

Ed Whitacre, who this week stepped down as CEO, earned a 90% approval rating. That outranks his predecessor, Fritz Henderson, who received a 67% rating in early 2009, before sliding down to a 52% score later that year.

Rick Wagoner, who was ousted as GM CEO in March 2009, held a 55% approval rating during his tenure between summer 2008 and spring 2009, the study indicates.

Chrysler CEO Sergio Marchionne’s approval rating was 56%, about average for all top executives, Besse says. “With Chrysler, there’s old and new (employees) with Fiat (Automobile SpA) ownership, but they’ve managed to improve overall ratings.”

Bob Nardelli, who stepped down at Chrysler in April 2009, garnered a 31% rating, the study shows.

Marchionne is “not as beloved as Whitacre was, but he’s not doing a bad job, either,” Besse says.