Parents also have the option of programming the teen's key to limit the audio system's volume, and to sound continuous alerts if the driver doesn't wear a seat belt.
"Our message to parents is, hey, we are providing you some conditions to give your new drivers that may allow you to feel a little more comfortable in giving them the car more often," said Jim Buczkowski, Ford's director of electronic and electrical systems engineering.
The feature, called "MyKey," will be standard on an unspecified number of Ford models when the 2010 cars and trucks come out late next summer. The feature will spread to the entire Ford, Lincoln and Mercury lineup as models are updated, spokesman Wes Sherwood said.
Ford arrived at the 80 mph limit even though freeway speed limits are lower in most states because it wanted to leave a margin in case an unusual situation arises, Buczkowski said. In some states, freeway speed limits are above 70 mph, Sherwood said.
"Just lopping it off at exactly 70 mph was felt to be too limiting," Buczkowski said.
The company already uses computer chips in its keys to prevent thefts. The car won't start unless it recognizes the chip in the key.
"It's making use of existing technology, and through the magic of software, we're able to build features on top of the features we already have," Buczkowski said.
In addition to speed limits, MyKey also will limit the volume of the audio system, and it will sound a six-second chime every minute if seat belts are not fastened. The chime sounds for adult drivers, too, but ends after five minutes to avoid annoying adults who adamantly don't want to wear seat belts, Buczkowski said.
Parents also have the option of having the car sound a chime if the teen exceeds 45, 55 or 65 mph.
Ford said its market research shows 75 percent of parents like the speed and audio limits, but as you might expect, 67 percent of teens don't like them.
Danisha Williams, a 16-year-old senior at Southfield-Lathrup High School in suburban Detroit, said she's against the idea.
"I wouldn't want my parents to have that much control over how I'm driving," she said. "If your parents are holding your hand, you're never going to learn."
Brittany Hawthorne, 17, another Southfield-Lathrup senior, said there may be emergency situations where she'd have to drive more than 80, possibly to accelerate to avoid a crash.
Ford's research shows that parents would be more likely to let teens use their vehicles with the system, Sherwood said, and if it gets them the car more often, the number of teens objecting drops by nearly half.
A top official from the Insurance Institute for Highway Safety, a research group funded by the auto insurance industry that is pushing to raise the minimum driving age to 17 or 18, found the key intriguing. IIHS says car crashes are the leading cause of death among teenagers.
"Research we've done has shown that speeding is a major factor in teen crashes, especially novice teen drivers," said Anne McCartt, the institute's senior vice president for research. "So I think a system that tries to correct the speeding behavior has the potential to improve safety."
More than 5,000 U.S. teens die each year in car crashes. The rate of crashes, fatal and nonfatal, per mile driven for 16-year-old drivers is almost 10 times the rate for drivers ages 30 to 59, according to the National Highway Traffic Safety Administration.