Trouble for pudgy cars: parking spaces are getting a lot slimmer

From the bumper-to-bumper bustle of downtown streets to the asphalt acres of suburban malls, Americans are learning to live with less - parking space, that is.

Ever since the 1973 Arab oil embargo crimped the style of gas-guzzling cars, ''scale down'' has been the phrase that pays in Detroit. So it was only a matter of time before cities, as well as private parking lot operators, saw the chance to cash in on the small-car trend:

* Los Angeles recently passed an ordinance allows new developments to parcel 40 percent of their parking to small cars.

* Developers of the Chesterfield Mall in Chesterfield, Mo., are narrowing parking spaces from 10 to nine feet. Result: 501 more spaces in an already 5,700 -space lot.

* In Boston, metered street parking spaces are being trimmed from about 23 to 20 feet. The move will net the city 17 percent more slots in metered areas.

''We're at a point where existing spacing is keeping some cars out of the city,'' says John Vitagliano, Boston's traffic and parking commissioner.

The bottom line, of course, is more cars inside the painted stripes and more people shelling out dimes and quarters. About 600 additional meters will be planted on Boston curbs in the months ahead.

Mr. Vitagliano says the city was planning to install thousands of new tamper-resistant meters anyway, so it was an ideal time to redesign the spaces.

The pared-down parking is made possible by the steady reduction in the size of American cars. Since 1975, the length of a standard-size car dropped by more than a foot, according to the Washington-based Urban Land Institute. Greater reductions have been made on compacts. Widths and wheelbases have also been trimmed.

''Based on the average, we can now reduce parking-stall sizes more than ever before,'' says Richard Roti, president of International Parking Design in California.

In some states - particularly in the West - well over half the cars are now ''small'' cars, says Mr. Roti. In California, for instance, more than 50 percent of the cars are shorter than 15 feet, while Michigan has slightly more than 15 percent in that category. By 1990, however, some parking experts foresee small cars accounting for 80 percent of the nation's auto population.

One way of jamming more cars on an acre of land is to set aside compact slots proportional to the number of small cars in the traffic mix. The idea was tried in the mid-1960s, but didn't catch on until the mid-'70s.

But Roti says small cars can't be relegated to the back of the lot. ''Small car parkers are going to feel just as entitled to park near front as the large cars, so you have to have patterns that encourage both groups to obey the rules.''

While creating small car spaces is efficient, it can cause problems. ''If you have a lot of small car spaces in your parking lot, and somebody comes along with a Cadillac and takes two - you haven't really gained anything,'' says Edward Whitlock, senior vice-president of the Connecticut-based consulting firm Wilber Smith & Associates.

Private developers, with an eye on building more shops or theaters on a piece of land, see dollar signs in smaller lots. In some cases, they have slightly reduced the size of all spaces, while also setting aside specific spaces for compacts.

''If you can reduce the overall size of the parking area, you can put the same size development on a smaller piece of land,'' says another parking consultant. But retail stores sometimes balk at parking changes, not wanting to inconvenience their shoppers. Most cities have ordinances - some dating from the 1950s - that specify the minimum size for parking spaces.

Meanwhile, if you're one of the people who grumble when you can't get the door on your Oldsmobile Toronado open, the picture isn't completely bleak. Experts figure angled parking spaces for full-size cars can't get much narrower than 8 feet.

The emphasis now, say parking consultants, is on designing more flexible lots - that can be changed to fit more cars at sharper angles in the future.