If you have AMBER lenses then choose to use AMBER LED bulbs as the light is much stronger than using WHITE.
Of course AMBER LED bulbs are suited to the new clear lenses also.
Base types available in this AMBER section:
Bayonet 1156 BA15S 15mm bayonet
Bayonet 1156 BAU15S 15mm bayonet
Wedge T10 9.3mm wedge base
Wedge T20 16mm 7440
Wedge T25 16mm 3156
T series numbering came from the diameter of the glass part of the incandescent bulb.
3156/3157: Replaces 25mm glass globe type
7440/7443: Replaces 20mm glass globe type
*** Both above lamps all have the (16mm) large wedge base.
T10 and T15
Both of these have the same 9.5mm small wedge base.
The T10 version is generally used in dashboards and other small recessed parts of the car.
They generally aren't used as reversing or parking lights.
The T15 version (which originally was a larger 15mm glass bulb) was a larger incandescent bulb and therefore as an LED equivalent we use the T15 LED lamp.
We enlarge the bulb's diameter & power for the T15 wedge accordinglyCode #194 comes from the GE number for T10mm glass globe lamp.
Code #906, 912, 921 ...comes from the GE number for T15mm glass globe lamp.