The Land Rover Discovery turn signal uses 7444NA and P21W bulb sizes according to the provided data. Information covers the range from 1995 through 2017 for the specified vehicle components.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The P21W is the most widely used bulb type across the Land Rover Discovery turn signal specifications, appearing in the front inner, front, and rear turn signal positions across the 1994-2004 model years. It follows the ECE standard used in Europe and worldwide markets, operates at 12V with a 21W output, and uses a BA15s single-contact bayonet base.
The BA15s bayonet base on the P21W is a single-contact fitting, meaning it is not interchangeable with dual-contact bayonet variants such as the BA15d, despite the physical housing appearing similar.
The front outer turn signal position on the Land Rover Discovery uses the 12961 across all listed model years from 1994-2002. This is a Philips part number designation for a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W, which is considerably lower in wattage than the P21W used in adjacent positions.
The 7444NA and 7443NA are dual-filament wedge bulbs following the ANSI standard used in the United States and Canada. Both operate at 12V with a 21W/5W output and feature natural amber glass, which produces an amber signal color without requiring an amber-tinted lens.
The 2019 Land Rover Discovery front turn signal uses the 7444NA specifically with halogen capsule headlamps, while the 2017 model uses the 7443NA under the same condition. Although the 7444NA and 7443NA share identical voltage and wattage ratings, they carry distinct ANSI designations and are not confirmed as interchangeable within these specifications.
The 2019 rear turn signal position uses the 7444NA, the same bulb type specified for the 2019 front turn signal with halogen capsule headlamps, indicating a consistent bulb type across both front and rear positions for that model year.
The front inner and front outer turn signal positions on the 1994-2002 Discovery require two different bulb types simultaneously, with the P21W serving the inner position and the lower-wattage 12961 serving the outer position. These two bulbs use entirely different base types and are not interchangeable with each other.
The T20 wedge base used by the 7444NA and 7443NA is physically larger than the T10 wedge base used by the 12961. The two wedge formats are incompatible despite sharing the same general wedge-style base design.
The front turn signal position transitions from the P21W in 2003-2004 to the 7444NA or 7443NA in 2017-2019, reflecting a shift from ECE-standard single-filament bayonet bulbs to ANSI-standard dual-filament wedge bulbs across those model years.
The dual-filament nature of the 7444NA and 7443NA means a single bulb serves two brightness levels within one housing, with the 21W filament typically active during signalling and the 5W filament serving as a parking or running light function.