The Kia Rio5 uses the 9003 bulb type for both high beam and low beam headlights across the 2006-2011 model years.
The 9003 is a dual-filament bulb, meaning a single unit contains separate filaments for both high and low beam functions. This design is also sold under the designation H4, and the two designations are generally considered interchangeable in the aftermarket.
Because the 9003 serves both beam functions in the Rio5, only one bulb type is required per headlight housing, rather than separate bulbs for each beam.
The 9003/H4 format uses a three-pronged connector and a P43t base, which is a standardized fitting. A bulb with a different base type would not seat correctly in the housing.
Dual-filament bulbs such as the 9003 carry two wattage ratings, typically 60 watts for high beam and 55 watts for low beam. Replacing the bulb with a single-filament type would result in the loss of one beam function.
The consistent use of the 9003 across all six model years indicates that the Rio5 headlight housing design did not change between 2006 and 2011, making bulbs from any of those years directly interchangeable with one another.