Chrysler Corp. has mailed tentative 1988 model pricing schedules to its dealers with increases that average about 7 percent from 1987 stickers.

Prices for the compact Dodge Aries and Plymouth Reliant were frozen at 1987 levels at $8,364. By contrast, some increases appear astronomical. The Dodge Grand Caravan and Plymouth Grand Voyager LE minivans, for example, went up by 23 percent, or $2,948, to $15,509 for 1988 from $12,561 for 1987.

Chrysler spokeswoman Karen Stewart said the price increases range from zero percent to 5 percent on a "comparable equipment" basis, meaning that in some cases equipment that had been standard will now be optional, or vice versa.

Without equipment factored in, she said, the increases average 7 percent.

Arvid Jouppi, an independent Detroit analyst, said equipment content is a technique auto makers use to keep percentage increases down while dollar amounts rise sharply.

When standard equipment is made optional, the auto maker deducts the retail cost of that item and considers it a price decrease.

When optional equipment is made standard, the auto maker adds the retail optional cost of those items to the sticker but doesn't count them in any increase.

The base price of the Chrysler LeBaron coupe, for example, went up by $178 to $11,473.

Stewart said that with equipment changes -- some items made optional -- the price is $82 lower than in 1987. She wouldn't elaborate on the changes.

Chrysler increased the amount of standard equipment on most high or premium lines for 1988.

For example, on the Grand Caravan/Voyager LE minivans, $2,576 of the $2,948 increase comes from optional equipment made standard -- air conditioning ($867); 3 liter V-6 engine ($619); seven-passenger seating ($401); automatic transmission ($549); and luggage rack ($140).

However, those were the retail prices of those options, and the dealer prices are less than what the customer typically pays.

Other notable increases are on the Chrysler LeBaron premium coupe, $1,542 or 12.5 percent to $13,830; the New Yorker turbo, $2,977 or 20.6 percent to $17,373; the LeBaron GTS premium, $1,204 to $12,971; the Dodge Diplomat SE, $2,543 to $14,221; and the Dodge Lancer ES, $1,904 to $12,715.

In each case, optional equipment has been made standard for 1988, such as a 2.5 liter 4-cylinder engine replacing the 2.2 liter 4 cylinder as standard on the Lancer ES, along with the addition of air conditioning.

The tentative 1988 prices are mailed early so that dealers can begin taking orders for the new model year cars and actually make deliveries on early arrivals from the factory.

Final prices won't be firmed up until fall, traditionally after pricing leader General Motors Corp. announces its prices and the competition falls in line to "remain competitive."

General Motors and Ford Motor Co. have not sent tentative prices to their dealers.

Chrysler officials and dealers said they expect that once buyers realize they are getting more equipment for the extra money, they'll accept the increases.

But analyst Jouppi said that he was not so sure.

Jouppi also said he was surprised at the extent of the increase, "considering the market is soft now and GM went to 1.9 percent financing to sell leftover '87s.

"But the proof of any price increase has to come later, in terms of sales," Jouppi said.

Chrysler didn't include the Dodge Omni or Plymouth Horizon L-body or the Chrysler New Yorker Brougham or Dodge Dynasty C-body cars in its pricing. The L-cars go into production at Kenosha, Wis., next month, and the C-cars go on sale in October.