is it time to use power fets instead of relays?

[sss]

hey guys
i needed to change the lights relay on my bike ,so i was thinking
there are many power mosfets that can do the job instead , but is it possible today to make a fet circuit with a small heatsink to switch 12A current on/off in the same size as regular 12A relay?
maybe even change the starter relay for a few fets .
i know its possible , but in my tests i needed a heat sink . so ,the size of the unit is the main issue here.
what do u think? are there any low RSon mosfets that can be compared (in size) to conventional relay?

[AndrewT]

stick with relays.

[Eva]

Relays are still the preferred method, unless you want to dim lamps and control speed and direction in motors.

In high-tech modern cars lamps are usually driven from integrated high-side switch ICs. They include a N-channel MOSFET with level shifting for gate drive, over current and over temperature protections and a load detection output (for open filament detection). In these cars PWM is usually employed to apply 12V RMS to the lamps when the engine is on. Switching is usually done locally, so that fuses and runs of wire are avoided.