The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity.
(Source - ibid.)
The cross-section area of solid 16 AWG copper wire is 0.002 sq. in. and 10 AWG wire is 0.008 sq. in. Obviously, 10AWG wire can carry more current (amps) than 16 AWG wire. (Do not assume that means four time as much -- the actual difference is based on complex formulae, in which the cross-sectional area is a factor, and experimentation.)
Wire that is too small for the current (amps) it is carrying will overheat, melting or burning the insulation and possibly causing a fire. The Blue Sea Systems website has a online
Circuit Wizard app that takes into account both the load current (in amps) and length of the conductor (wire, in feet) to identify the appropriate wire gauge.
I've been involved in three vehicle fires, all caused by overloaded wires due to short circuits or previous owners using too small wires. For that reason, I usually go to one size larger wire (i.e., 14 AWG wire when 16 AWG is considered adequate.) to reduce the chances of experiencing another vehicle fire.
