A boom in truck buying in the 1990s helped push the resale value of pickups and sport utility vehicles to levels well above most cars, but market forces are starting to pull them back down, according to the Chicago Tribune.

When Paul Taylor, an economist for the National Automobile Dealers Association (NADA), tracked the values of the best-selling 1999 vehicles from January 2000 to January 2001, four of the five biggest losers were trucks. The Ford Explorer dropped 20 percent, the Ford Expedition 14.5 percent, Dodge Grand Caravan 14.4 and the Dodge Ram pickup 14.

Popular SUVs such as the Chevy Blazer, Jeep Grand Cherokee and Dodge Durango also are losing

value as buyers embrace so-called crossover SUVs such as the Ford Escape, Honda CR-V, Toyota Highlander, Subaru Forester, Acura MDX, Lexus RX 300 and others that are based on car platforms instead of trucks.

"That is consistent with the market and a shift in consumer preference for crossover utility vehicles," Taylor said.

"In the past, it wasn't unusual for trucks to go 10 or 15 years without a redesign. Now you're

seeing a pretty dramatic decrease in product life cycles," said Derek Humphrey, manager of North American forecasting for J.D. Power and

Associates.

NADA's Taylor suggests that dealers increase efforts to minimize the number of days that used cars are held, since the value of certain models may drop faster than expected as the supply of used cars increases this year. Even with interest rates for financing inventory falling, faster depreciation of used-vehicle prices can reduce the gross margin from a used car that sits on the lot too long.

An alternative strategy is to go to auction

for cars more often, minimizing the time they are held. Auction purchases accounted for 33 percent of the new cars retailed by franchised dealers in 2000. The good news is that gross margins and net profits per used vehicle retailed are improving in the first quarter's data compared with the same quarter last year. And the ample supply means that auctions will have lots of the popular models, according to Taylor.