I conducted an LED “shootout” in the both the front and rear turn signals of an RS faired bike. (My K75.)
To start with, don’t even bother trying “old style” LEDs. The LED 1156 bulbs I tried are all newer “SMD” (surface mounted) LEDs. Here are the bulbs I tested: (see attached pic)
- a regular old 1156 filament bulb
- 18 SMD LED 1156 bulb
- 35 SMD LED 1156 bulb
- 45 SMD LED 1156 bulb
Here are my results. I came to the same conclusion for both the front and rear turn signals.
Best: Filament bulb. Brighter and fuller than any of the LED bulbs tested.
Second: This is a tie between the 18 and 45. Both did about the same job in terms of brightness and filling out the turn signal lenses. I’d opt for the 18 SMD bulb (what I currently run in most of my bikes) because, though fewer in number, the individual SMD LEDs are bigger and brighter.
Third: At least for the bulbs I tested, the 35 SMD LED bulb was a darker amber and was the least bright.
Using 1157 dual brightness SMD LED bulbs: I’ve experimented with these and the low light from these is pretty dim. It’s barely visible during the day and somewhat visible at night. Because of that, I wouldn’t bother using 1157 SMD LEDs as running lights. If you really want to have your turn signals act as running lights then IMO your best bet is to run 1157 filament bulbs in Run-N-Lites K bike sockets.
I did not bother taking pictures because digital camera sensors process light differently then the human eye does. And what matters is how the human eye processes light when it comes to other road users seeing your turn signals.
Probably the best: Recently, CREE (an American LED company) has revolutionized the LED industry and the brightest flashlights and driving lights now have CREE LEDs in them. I've noticed some CREE 1156 amber bulbs on eBay and haven't tried them yet but, based on some other CREE led lights I've got, I'll bet they're pretty awesome.
http://www.ebay.com/itm/GP-Thunder-1156-7506-Cree-SMD-High-Power-Turn-Signal-Parking-Amber-Light-Bulbs-/120928703021?pt=Motors_Car_Truck_Parts_Accessories&hash=item1c27e9922d&vxp=mtr#ht_2626wt_930(Note: Unless you use the kludgy old 6 ohm 50W load resistors in parallel with each LED bulb, your OEM flasher relay will think all of your bulbs are out and hyperflash. Alternatives for running LED turn signals are to build your own LED flasher relay (see The Lieberry for details on this) or run an SM-6 Kisan Signalminder.)