A while back I blew a brake light, and standing in the aisle at Canadian Tire I decided to go with a pair of the highest wattage they had, as of course that's safer right? I got some 2357, 28/8W.
Well then, perhaps related, I had some low voltage issues with the bike when running in crap traffic (I generally keep my brakes on sitting at lights), which is no fun. But got good at bump-starting my bike.
A new battery, some testing of my charging system (all good) and a voltage display later, I was still seeing pretty uncomfortable voltage drop while sitting at stop lights, so I decided to invest in some LED brake lights. Taking Land Roving's advice in a long ago thread, I picked up some VLED 1157 replacements, $50 for the pair which doesn't seem too steep.
WOW these things are bright!
So this is comparing LED vs. incandescent, running lights ...
And brake lights
The camera really doesn't show it well, the LED brake light basically overwhelms the incandescent. VLed claims a 1:6 ratio, I believe it. And they have that super fast on/off which I think is more noticeable; I often flicker the brake lights as a car is pulling up behind me and these things look like strobe lights.
Some numbers for the data geeks, this is the current draw of one lamp, engine off, fully charged battery:
2357 running: 0.54A
2357 brake: 2.5A
LED running: 0.06A
LED brake: 0.42A
Any my voltage hangs at much more comfortable levels while at long lights. Money well spent, I'd say.