STAMFORD, Conn. -

Used-vehicle volume is down more than 7 percent year-over-year in 2012, helping to spur robust prices in the used market, according to RVI Group.

In fact, the RVI  Used Car Price Index climbed 8.1 percent year-over-year in February to 1.422, which marked a modest 0.4-percent rise from January.

Officials noted that when MSRP is taken into account, used prices were up 5.2 percent year-over-year and  climbed 0.6 percent month-over-month.

“Auction volume has contributed to the strong used car market, declining 7.6 percent on an annualized basis so far in 2012,” officials indicated. This continues what has been consecutive years of auction volume declines, according to RVI’s data. The RVI Auction Supply Index fell from almost 1.6 in 2009 to around 1.2 in 2010, then dipped to just over 0.8 in 2011. The 2012 index is close to 0.8.

As for pricing, RVI broke down its price index by segment. It showed that prices for all 19 vehicle categories were up from February 2011, with seven showing double-digit gains.

The strongest year-over-year increase was for the luxury full-size sedan class (up 19.1 percent), followed by sports cars (up 15.9 percent), subcompacts (up 15.6 percent) and luxury coupes (up 14.6 percent).

Others showing double-digit hikes were full-size SUVs (up 13.8 percent), sporty coupes (up 11.3 percent) and compacts (up 10.8 percent).

On a sequential basis, luxury midsize sedans showed the most growth (up 1.8 percent) with midsize sedans (up 1.5 percent) and luxury full-size sedans (up 1.4 percent) next in line, respectively.

Five segments saw their prices fall from January: full-size vans (down 1.7 percent), luxury coupes (down 1.4 percent), small SUVs (down 0.4 percent), full-size sedans (down 0.3 percent) and midsize SUVs (down 0.1 percent).