Yes thats true for petrol, I mentioned diesel, bosch like a lot of others use a 48v supply, and they are much faster than petrol and open in much less than a ms, they have to as the rail pressure is in the order of 1000's of psi, unlike petrols diesel engines vary the rail pressure, the injector is also driven with pwm as they have diffrent opening positions to control the spray pattern.
If you spring load your solenoid so that the spring holds the armature in the actuated position you'll speed it up a little, as when it fires the spring will be assisting you, this of course assumes the solenoid can be driven both ways, some do some dont.