The ATK GV650 headlight bulb specifications include an H1 size for high beam and H3 size for low beam applications. The replacement chart covers 2011 through 2014 production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The ATK GV650 uses the H1 bulb for high beam headlights across the 2011-2014 model years, and the H3 bulb for low beam headlights across the same range.
Both the H1 and H3 are single-filament halogen bulbs operating at 12V and 55W, meaning each bulb handles only one lighting function rather than combining high and low beams in a single unit.
The H1 uses a P14.5s base, while the H3 uses a PK22s base. These two base types are physically incompatible with each other, so the high beam and low beam positions do not accept the same bulb despite sharing identical voltage and wattage ratings.
Both bulb types are manufactured to the ECE standard, which governs lighting equipment across Europe and much of the world, and both also carry approval for use in the United States and Japan.
Because the H1 and H3 share the same 12V/55W electrical rating but differ in base design, substituting one for the other in the GV650 is not possible without a physical mismatch at the socket.