The BMW 340i uses H7 bulb sizes for both high beam and low beam headlight applications. Replacement specifications in the chart cover 2016 to 2018 model production years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW 340i uses the H7 bulb type for both high beam and low beam headlights across the 2016-2018 model years, and this applies specifically to vehicles equipped with halogen capsule headlamps.
The H7 is a single-filament halogen bulb, meaning it contains one tungsten filament and is dedicated to a single lighting function rather than serving dual purposes within one housing.
H7 bulbs operate on a 12-volt electrical system and draw 55 watts, which are standard ratings for halogen headlamp applications in passenger vehicles.
The H7 uses a PX26d base, a two-pin connector with a specific keyed orientation that prevents incorrect installation and is not interchangeable with other base types such as P43t or PGJ19.
The H7 is an ECE-regulated bulb, meaning it conforms to the Economic Commission for Europe lighting standard, which governs beam pattern, intensity, and color temperature for road use.
Although the H7 originates as a European standard, it also carries approval for use in the United States and Japan, giving it broad regulatory acceptance across major automotive markets.
Because both the high beam and low beam positions on the 340i share the same H7 specification, the same bulb part number applies to either position, though each position occupies a separate housing and socket.
The halogen capsule headlamp condition noted in the specifications indicates that vehicles fitted with non-halogen systems, such as adaptive or full-LED headlamps, follow a different bulb configuration not covered by these entries.