I used these to replace backup bulbs on an 03 marauder and 08 lincoln Town Car. They call for a 3156 bulb. Also used the 1156 (same bulb/different base0 on a 98 Subaru reverse lights. When used like this all emitters light up. I was a bit concerned that would not be the case. No worries. I say these are a good value because they are bright and seem sturdy.I tried a couple of other , cheaper, 3156 type leds and these antline knocked them out of the park on brightness. I will just give those other cheap ones away.Other cheaper ones would probably be fine if you just want an LED replacement, long life and low power consumption, equivalent to an incandescent bulb in brightness. If you want more light you can buy these.I think they would be plenty bright for turn signals. If you use them on modern cars for turn signals you will likely need can-bus ready bulbs resistors depending on the particular car. More advanced folks could possibly reprogram or rewire the car. Do your research first.Older cars likely will require just a new plug in electronic flasher unit. If you do all your flashing bulbs you need the low amp flasher units not just the regular electronic units.Jay