Boiler pressure?

No, BUT. Please read the note at the end.

Pressure is heat. Higher pressure means there is more heat in the system, and your radiators will operate at a higher temperature.

Lowering the temperature, and therefore the pressure, will mean that your radiators will run at a lower temperature, but your boiler system will have to operate longer at that lower output in order to keep your home at the desired temperature. There isn't any sensible gain to by had by doing this.

If you want to reduce your fuel consumption, add insulation.

PLEASE NOTE, 10 bar sounds kind of high for a home heating boiler and equates to about 345 degrees F / nearly 175 C, are you certain you're reading that right?

You make heat in your boiler.

You transfer that heat to your radiators.

The rooms are remotely heated.

You can't just make something different to get the same heat and use less fuel.

If you use less fuel than is necessary, the rooms will be heated less.

Maybe you could get a more efficient boiler if you want to use less fuel.

But a higher efficiency boiler costs money.

You could hire a heating engineer to check your system, to find if there is a fault.

Just wanting to use less fuel, could be unrealistic and impossible.

Maybe you could investigate your heat loss and try to reduce it.

you are wrong / you have to change the thermostat setting

You clearly don't understand how your heating system works.

10 bar is 145 psi. Are you sure? You must be reading the meter incorrectly.

you must have missread it ..no more than 2 is standard ...you can drop pressure by bleeding rad

10 bars??? Are you reading the pressure right? If the pressure is correct, shut off the boiler IMMEDIATELY and call a plumber/heating technician.

Bleed a radiator until 2.0 bar appears. The pressure should never get anywhere near 10 bar. I can only assume you over pressurised it yourself. If not, turn off or disconnect the filling loop if possible as it's letting by. If there is no flexy filling loop call in a heating engineer as a valve is faulty. Boiler pressure has no effect at all on gas consumption.