FAV Voltage

[turbonutter]

Hi,
I am using an Aquamist FAV to control the WI on my system, controlled by my engine ECU. I am currently wiring it up & was about to connect it to +12V, but noticed the coil is marked 6V DC.

What would be the best way to connect it to +12V and use a maximum of 50% duty from the ECU output (Low Side PWM) or I can connect to a +5V supply & use the full 100% signal, but then I guess the valve will only open 80% maximum?

Thanks
Neil