In #"1 cubic metre"# there are #1000# #L#.
#17.3*cm^3# #=# #17.3xx(10^-2m)^3#, i.e. #"centi" =10^-2#
#=# #17.3xx(10^-2m)^3# #=# #17.3xx10^-6*m^3#
#=# #17.3xx10^-6*cancel(m^3)# #xx# #10^3*L*cancel(m^-3)#
#=# #17.3xx10^-3*L#
#=# #0.0173*L" as required".#
In England, sometimes we replace #L# with #dm^-3# #=# #(10^-1*m)^3# #=# #10^-3*m^3# #=# #1L#. Mind you, now England has left the EU we might even move back to #"pints"#, and #"furlongs"#.