By Jim Mateja,Chicago Tribune

CHICAGO – General Motors is hoping to lure buyers by eliminating the need for – and the expense of – having a navigation system with a screen in the dashboard to map directions.

GM’s plan is to harness its OnStar satellite communications system, which provides in-car emergency services, to act as navigator. Named Turn by Turn, the system calls on satellites that allow OnStar to pinpoint your car in an emergency to do the work of the navigation screen.

Instead of relying on a keypad or touch screen, a driver will communicate with an OnStar adviser, who will program the route and digitally feed it back to the car, where it’s relayed through radio speakers.

“As you drive, when you come to a point where you should turn right, the radio mutes and the recorded voice tells you to turn right and keeps telling you where to go until you get to your destination,” said Chet Huber, president of General Motors OnStar subsidiary.

“The idea was to make navigation simple so you needn’t be a rocket scientist to make it work and could take it to the mass audience without charging $2,000,” he said.

But Art Spinella, general manager of CNW Marketing Research, wondered how much buyers will like the differences.

“Years ago a company took the alcohol out of its antiperspirant so it wouldn’t sting and sales fell because without the sting, consumers didn’t think the antiperspirant was doing its job,” said Spinella. “Same thing with a navigation system. People like to have a map on a screen to look at to know it’s working rather than wait to listen to voice commands.”

Only about 5 percent of vehicles sold each year have a navigation system as standard or optional and usually only the upscale ones because the cost is high.

“Demand is low and so is usage. There’s a potential for growth, but it’s from people who never had one before because most navigation system owners don’t get one again,” Spinella said. “There’s little need for a map telling you there’s a McDonald’s at the next exit on the interstate when signs alongside the road do that.”

GM, on the other hand, has racked up 4 million subscribers in the 10 years it has offered OnStar. Turn by Turn will be offered in the Buick Lucerne and Cadillac DTS and STS in March and then in 1 million other GM vehicles for the 2007 model year. By 2010, GM said, OnStar will be standard in all its vehicles and able to offer Turn by Turn. But the system can’t be retrofitted to any 2006 or later model other than Lucerne, DTS and STS.

“Whether it will steer people into a GM vehicle is hard to say. It all depends on the cost,” said Rebecca Lindland, senior analyst with Global Insight. “People all say they want run-flat tires, but when they find out how much they cost, they do without them.”