The Hyosung GT250R uses an H1 bulb size for the high beam headlight and an H3 bulb size for the low beam headlight. The replacement chart covers vehicle production years spanning 2007 to 2017 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Hyosung GT250R uses the H1 bulb type for the high beam headlight across all model years from 2007-2017.
The H1 is a single-filament halogen bulb operating at 12V and 55W, fitted with a P14.5s base, and is rated under the ECE standard with approval also recognized in the US and Japan.
The low beam headlight on the GT250R is served by the H3 bulb type across the same 2007-2017 model year span.
The H3 shares the same 12V, 55W halogen single-filament construction as the H1 but uses a PK22s base, which is a pin-type connector rather than the bayonet-style P14.5s base of the H1, making the two bulbs physically incompatible with each other.
Both the H1 and H3 carry ECE certification, meaning they conform to the Economic Commission for Europe lighting regulations that govern photometric output and construction standards across European and many worldwide markets.
Despite sharing identical wattage and voltage ratings, the H1 and H3 are not interchangeable due to their differing base types, and substituting one for the other is not supported by the fitment data for the GT250R.