have you tested psi on a 2.5 nozzle? after watching all those videos that matt at og made i assume you want around 1000 psi to wash a car so 900 sounds good.
from what i understand, higher flow or gpm makes better foam. and in his case, he has a pressure washer to foam and to help wash his cars which is why he shoots for 1000 psi. but with lower flow...
can you feel the difference between 1100 psi and 1300 psi? so would a 2.0 feel like its putting out more than a 2.5 or would it be hard to tell without a gauge?