Yes, it is good to have one on standby, but usually those small
one is not that effective. For small vehicle/van, at least a 2.5kg
dry powder fire extinguisher, rather using 1kg type. For
lorry...etc, a 9kg type is suggested. However, if fire really
started in engine compartment, how you can open the front bonnet if
you see fire seeping out, still dare to slot your fingers in to
open the latch?
By the way, a small fire extinguisher like 1kg can only last for
less than 7-8 secs if the lever is fully pressed.